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Conserved domains on  [gi|1796318598|ref|YP_009724390|]
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surface glycoprotein [Severe acute respiratory syndrome coronavirus 2]

Protein Classification

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List of domain hits

Name Accession Description Interval E-value
SARS-CoV-like_Spike_SD1-2_S1-S2_S2 cd22378
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
543-1208 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from SARS-CoV-2 (COVID-19) and related betacoronaviruses in the B lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the sarbecovirus subgenus (B lineage), including highly pathogenic human CoVs such as Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS-CoV-2 (also known as a 2019 novel coronavirus or 2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. Notably, SARS-CoV-2 has a functional polybasic (furin) cleavage site through the insertion of PRRAR*SV (* indicates the cleavage site) at the S1/S2 interface, which is absent in SARS-CoV and other SARS-related coronaviruses. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


:

Pssm-ID: 411965 [Multi-domain]  Cd Length: 662  Bit Score: 1400.89  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  543 FNGLTGTGVLTESNKKFLPFQQFGRDIADTTDAVRDPQTLEILDITPCSFGGVSVITPGTNTSNQVAVLYQDVNCTEVPV 622
Cdd:cd22378      1 FNGLTGTGVLTPSSKRFQPFQQFGRDVSDFTDSVRDPKTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  623 AIHADQLTPTWRVYSTGSNVFQTRAGCLIGAEHVNNSYECDIPIGAGICASYQTQTnsprRARSVASQSIIAYTMSLGAE 702
Cdd:cd22378     81 AIHADQLTPAWRVYSTGSNVFQTQAGCLIGAEHVNTSYECDIPIGAGICASYHTVS----LLRSTSQKSIVAYTMSLGAE 156
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  703 NSVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVF 782
Cdd:cd22378    157 NSIAYSNNSIAIPTNFSISVTTEVMPVSMAKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALSGIAVEQDKNTQEVF 236
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  783 AQVKQIYKTPPIKDFGGFNFSQILPDPSKPSKRSFIEDLLFNKVTLADAGFIKQYGDCLGDIAARDLICAQKFNGLTVLP 862
Cdd:cd22378    237 AQVKQMYKTPTIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDINARDLICAQKFNGLTVLP 316
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  863 PLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTA 942
Cdd:cd22378    317 PLLTDEMIAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKQIANQFNKAISQIQESLTTTS 396
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  943 SALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASA 1022
Cdd:cd22378    397 TALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASA 476
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1023 NLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGKAHFPREGVFVSNGTHW 1102
Cdd:cd22378    477 NLAATKMSECVLGQSKRVDFCGKGYHLMSFPQAAPHGVVFLHVTYVPSQERNFTTAPAICHEGKAYFPREGVFVSNGTSW 556
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1103 FVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKE 1182
Cdd:cd22378    557 FITQRNFYSPQIITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKE 636
                          650       660
                   ....*....|....*....|....*.
gi 1796318598 1183 IDRLNEVAKNLNESLIDLQELGKYEQ 1208
Cdd:cd22378    637 IDRLNEVAKNLNESLIDLQELGKYEQ 662
SARS-CoV-2_Spike_S1_RBD cd21480
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome coronavirus 2 ...
319-541 7.24e-166

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome coronavirus 2 Spike (S) protein; This group contains the receptor-binding domain of the S1 subunit of the spike (S) protein from highly pathogenic human virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV). The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While RBD of mouse hepatitis virus (MHV) is located at the NTD, most of other CoVs, including SARS-CoV-2 use the C-domain to bind their receptors. Recent studies found that the receptor-binding domain (RBD) of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV-2 and most CoVs.


:

Pssm-ID: 394827  Cd Length: 223  Bit Score: 492.30  E-value: 7.24e-166
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  319 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 398
Cdd:cd21480      1 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  399 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGST 478
Cdd:cd21480     81 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGST 160
                          170       180       190       200       210       220
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1796318598  479 PCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 541
Cdd:cd21480    161 PCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 223
SARS-CoV-like_Spike_S1_NTD cd21624
N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory ...
13-304 4.14e-152

N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory syndrome coronavirus and related betacoronaviruses in the B lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the sarbecovirus subgenera (B lineage), including the highly pathogenic human coronavirus (CoV), Severe acute respiratory syndrome (SARS) CoV, and SARS-CoV-2, also known as a 2019 novel coronavirus (2019-nCoV) or COVID-19 virus. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2 and SARS-CoV, use the C-domain to bind their receptors. The S1 NTD contributes to the Spike trimer interface.


:

Pssm-ID: 394950  Cd Length: 280  Bit Score: 458.34  E-value: 4.14e-152
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   13 SQCVNLTTRTQLPPAYTNSFTRGVYYPDKVFRSSVLHSTQDLFLPFFSNVTWFHAIHVSGtNGTKRFDNPVLPFNDGVYF 92
Cdd:cd21624      1 EGCTTFSDKTAPNMTQYSSSRRGVYYPDDIFRSDVLVLTQDYFLPFNSNVTWYHSLNALG-ERKYYFDNPVLPFGDGVYF 79
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   93 ASTEKSNIIRGWIFGTTLDSKTQSLLIVNNATNVVIKVCEFQFCNDPFLGVYYHknnksWMESEFRVYSSANNCTFEYVS 172
Cdd:cd21624     80 AATEKSNVVRGWIFGSTFDNTSQSAIIVNNGTHIIIRVCNFQLCKNPMFAVSKP-----GTQTNSWIYSNAFNCTYEYVS 154
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  173 QPFLMDLEGKQGNFKNLREFVFKNIDGYFKIYSKHTPINLVRDLPQGFSALEPLVDLPIGINITRFQTLLALHRSYLtpg 252
Cdd:cd21624    155 QSFQLDVSEKNGNFKHLREFVFKNVDGFLKVYHGYQPINVVRGLPSGFSVLKPIFKLPLGINITNFRVVLTMFSPAQ--- 231
                          250       260       270       280       290
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1796318598  253 dssSGWTAGAAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKCTLK 304
Cdd:cd21624    232 ---SNWTAGNAAYYVGYLKPTTFMLKFDENGTITDAVDCSQDPLAELKCTLK 280
 
Name Accession Description Interval E-value
SARS-CoV-like_Spike_SD1-2_S1-S2_S2 cd22378
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
543-1208 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from SARS-CoV-2 (COVID-19) and related betacoronaviruses in the B lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the sarbecovirus subgenus (B lineage), including highly pathogenic human CoVs such as Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS-CoV-2 (also known as a 2019 novel coronavirus or 2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. Notably, SARS-CoV-2 has a functional polybasic (furin) cleavage site through the insertion of PRRAR*SV (* indicates the cleavage site) at the S1/S2 interface, which is absent in SARS-CoV and other SARS-related coronaviruses. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411965 [Multi-domain]  Cd Length: 662  Bit Score: 1400.89  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  543 FNGLTGTGVLTESNKKFLPFQQFGRDIADTTDAVRDPQTLEILDITPCSFGGVSVITPGTNTSNQVAVLYQDVNCTEVPV 622
Cdd:cd22378      1 FNGLTGTGVLTPSSKRFQPFQQFGRDVSDFTDSVRDPKTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  623 AIHADQLTPTWRVYSTGSNVFQTRAGCLIGAEHVNNSYECDIPIGAGICASYQTQTnsprRARSVASQSIIAYTMSLGAE 702
Cdd:cd22378     81 AIHADQLTPAWRVYSTGSNVFQTQAGCLIGAEHVNTSYECDIPIGAGICASYHTVS----LLRSTSQKSIVAYTMSLGAE 156
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  703 NSVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVF 782
Cdd:cd22378    157 NSIAYSNNSIAIPTNFSISVTTEVMPVSMAKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALSGIAVEQDKNTQEVF 236
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  783 AQVKQIYKTPPIKDFGGFNFSQILPDPSKPSKRSFIEDLLFNKVTLADAGFIKQYGDCLGDIAARDLICAQKFNGLTVLP 862
Cdd:cd22378    237 AQVKQMYKTPTIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDINARDLICAQKFNGLTVLP 316
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  863 PLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTA 942
Cdd:cd22378    317 PLLTDEMIAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKQIANQFNKAISQIQESLTTTS 396
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  943 SALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASA 1022
Cdd:cd22378    397 TALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASA 476
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1023 NLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGKAHFPREGVFVSNGTHW 1102
Cdd:cd22378    477 NLAATKMSECVLGQSKRVDFCGKGYHLMSFPQAAPHGVVFLHVTYVPSQERNFTTAPAICHEGKAYFPREGVFVSNGTSW 556
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1103 FVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKE 1182
Cdd:cd22378    557 FITQRNFYSPQIITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKE 636
                          650       660
                   ....*....|....*....|....*.
gi 1796318598 1183 IDRLNEVAKNLNESLIDLQELGKYEQ 1208
Cdd:cd22378    637 IDRLNEVAKNLNESLIDLQELGKYEQ 662
CoV_S2 pfam01601
Coronavirus spike glycoprotein S2; The coronavirus spike glycoprotein forms the characteriztic ...
710-1211 0e+00

Coronavirus spike glycoprotein S2; The coronavirus spike glycoprotein forms the characteriztic 'corona' after which the group is named. The Spike glycoprotein is translated as a large polypeptide that is subsequently cleaved to S1 pfam01600 and S2,. The S2 subunit normally contains multiple key components, including one or more fusion peptides (FP), a second proteolytic site (S2') and two conserved heptad repeats (HRs), driving membrane penetration and virus-cell fusion. The HRs can trimerize into a coiled-coil structure built of three HR1-HR2 helical hairpins presenting as a canonical six-helix bundle and drag the virus envelope and the host cell bilayer into close proximity, preparing for fusion to occur.


Pssm-ID: 460263  Cd Length: 502  Bit Score: 661.66  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  710 NSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVFAQVKQIY 789
Cdd:pfam01601    1 GNISIPTNFTISVQTEYIQTTSPKVSVDCAQYVCNGNERCLQLLVQYGSFCSTIEQALQGSARLEDVEVLSMLSISNRAL 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  790 KTPPIKDFGG-FNFSQILPDPskPSKRSFIEDLLFNKVTLADAGFIKQYGDCLGDIAARDLICAQKFNGLTVLPPLLTDE 868
Cdd:pfam01601   81 TLATISNFGSdFNFSSFLPCL--NSGRSAIEDLLFDKVVTSGLGTVDAYKKCTKGTSIADLVCAQYYNGIMVLPGVVDAE 158
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  869 MIAQYTSALLAGTITSGWTFGAGAalqIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTASALGKL 948
Cdd:pfam01601  159 KMAMYTASLTGGMAFGGLTGAAAA---IPFALAVQARLNYLGLQTDVLQENQKILANAFNNAVGNITDGFTTTASALSKI 235
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  949 QDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATK 1028
Cdd:pfam01601  236 QDVVNANAQALNQLTQQLSNNFGAISSSIQDIYSRLDQLEADAQVDRLINGRLAALNAFVTQQLTKASEVKASRQLAQQK 315
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1029 MSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGK-AHFPREGVFVSNGTH-WFVTQ 1106
Cdd:pfam01601  316 VNECVKSQSSRYGFCGNGTHLFSLPQAAPNGIMFLHTVLVPTEYITVKATPGLCVNGTtGYAPRDGQFVLNNTSnWYITP 395
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1107 RNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLgDISGINASVVNIQKEI--- 1183
Cdd:pfam01601  396 RNMYQPRPITGSDFVQISSCDVNFVNITNTKLPPLIPDYVDFNKELEDIYKNLNSTLPDL-DLDIFNATILNLTDEIkdl 474
                          490       500
                   ....*....|....*....|....*...
gi 1796318598 1184 DRLNEVAKNLNESLIDLQELGKYEQYIK 1211
Cdd:pfam01601  475 ERLQELIDNLNQTLVDLEWLNRYETYIK 502
SARS-CoV-2_Spike_S1_RBD cd21480
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome coronavirus 2 ...
319-541 7.24e-166

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome coronavirus 2 Spike (S) protein; This group contains the receptor-binding domain of the S1 subunit of the spike (S) protein from highly pathogenic human virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV). The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While RBD of mouse hepatitis virus (MHV) is located at the NTD, most of other CoVs, including SARS-CoV-2 use the C-domain to bind their receptors. Recent studies found that the receptor-binding domain (RBD) of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV-2 and most CoVs.


Pssm-ID: 394827  Cd Length: 223  Bit Score: 492.30  E-value: 7.24e-166
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  319 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 398
Cdd:cd21480      1 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  399 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGST 478
Cdd:cd21480     81 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGST 160
                          170       180       190       200       210       220
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1796318598  479 PCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 541
Cdd:cd21480    161 PCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 223
SARS-CoV-like_Spike_S1_NTD cd21624
N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory ...
13-304 4.14e-152

N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory syndrome coronavirus and related betacoronaviruses in the B lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the sarbecovirus subgenera (B lineage), including the highly pathogenic human coronavirus (CoV), Severe acute respiratory syndrome (SARS) CoV, and SARS-CoV-2, also known as a 2019 novel coronavirus (2019-nCoV) or COVID-19 virus. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2 and SARS-CoV, use the C-domain to bind their receptors. The S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394950  Cd Length: 280  Bit Score: 458.34  E-value: 4.14e-152
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   13 SQCVNLTTRTQLPPAYTNSFTRGVYYPDKVFRSSVLHSTQDLFLPFFSNVTWFHAIHVSGtNGTKRFDNPVLPFNDGVYF 92
Cdd:cd21624      1 EGCTTFSDKTAPNMTQYSSSRRGVYYPDDIFRSDVLVLTQDYFLPFNSNVTWYHSLNALG-ERKYYFDNPVLPFGDGVYF 79
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   93 ASTEKSNIIRGWIFGTTLDSKTQSLLIVNNATNVVIKVCEFQFCNDPFLGVYYHknnksWMESEFRVYSSANNCTFEYVS 172
Cdd:cd21624     80 AATEKSNVVRGWIFGSTFDNTSQSAIIVNNGTHIIIRVCNFQLCKNPMFAVSKP-----GTQTNSWIYSNAFNCTYEYVS 154
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  173 QPFLMDLEGKQGNFKNLREFVFKNIDGYFKIYSKHTPINLVRDLPQGFSALEPLVDLPIGINITRFQTLLALHRSYLtpg 252
Cdd:cd21624    155 QSFQLDVSEKNGNFKHLREFVFKNVDGFLKVYHGYQPINVVRGLPSGFSVLKPIFKLPLGINITNFRVVLTMFSPAQ--- 231
                          250       260       270       280       290
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1796318598  253 dssSGWTAGAAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKCTLK 304
Cdd:cd21624    232 ---SNWTAGNAAYYVGYLKPTTFMLKFDENGTITDAVDCSQDPLAELKCTLK 280
bCoV_S1_N pfam16451
Betacoronavirus-like spike glycoprotein S1, N-terminal; This entry represents the N-terminal ...
34-334 8.49e-65

Betacoronavirus-like spike glycoprotein S1, N-terminal; This entry represents the N-terminal domain of the betacoronavirus-like trimeric spike glycoprotein. The distal S1 subunit of the coronavirus spike protein is responsible for receptor binding. S1 contains two domains; an N-terminal galectin-like domain (NTD) and a receptor-binding domain (S1 RBD) also referred to as the S1 CTD or domain B. Either the S1 NTD or S1 RBD, or occasionally both, are involved in binding to host receptors. S1 NTD is located on the side of the spike trimer and mainly recognizes sugar receptors. For many betacoronaviruses (b-CoVs), for example mouse hepatitis virus (MHV), the RBD is located in the NTD. The structure of the MHV S1 NTD showed the same fold as human galectins (galactose-binding lectin), however it does not bind any sugar; instead, it binds to the carcinoembryonic antigen cell-adhesion molecule CEACAM1) through protein-protein interactions. All three CEACAM21a-binding sites in MHV spikes can be fully occupied by CEACAM1a. It has been shown that CEACAM1a binding to the MHV spike weakens the interactions between S1 and S2 and facilitates the proteolysis of the spike protein and dissociation of S1. The homologous bovine CoV (BCov) S1 NTD also possesses a galectin fold but binds to sialic acid-containing moieties on host cell membranes, as does the NTD of three other group A b-Covs, namely human CoV (HCoV) OC43, avian b-CoV, and infectious bronchitis virus (IBV). Despite the S1 NTD of human respiratory b-CoV HKU1 being highly homologous to the NTDs of MHV and bovine CoV, it does not bind to either sugar or human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) and the RBD is found instead in the S1 RBD domain.


Pssm-ID: 465119  Cd Length: 296  Bit Score: 221.90  E-value: 8.49e-65
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   34 RGVYY-PDKVFrSSVLHSTQDLFLPFFSNVTWFhAIHVSGTNGTKRFDNPVLPFNDGVYFASTEKSNIIRG--------W 104
Cdd:pfam16451    6 DGTYYlPDRVY-SNTTTLRQGLFPKQGDNVTNY-VYSPAHHCGKRNFSTPFLPFGDGIFVHIGNASNATGGriiseppaF 83
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  105 IFGTTLDSKTQSLLIVNNA--TNVVIKVCEFQFCNDPFLGVyyhknnkSWMESEFRVYSS------ANNCTFEYVSqPFL 176
Cdd:pfam16451   84 VFGSTFGNTSHTLIIAPDScqTNLTILVCNFTLCANPVTAC-------RWGAGNYNANNSlvyfknAINCTFNRTY-NIT 155
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  177 MDlegkqgnfKNLREFVFKNIDGYFKIYSKHTPInlvrDLPQGFSALEPLVDLPIGINITRFQTLLalhRSYltpgDSSS 256
Cdd:pfam16451  156 FD--------TSLIYFGFKQQDGGFHIYYSYWLP----DLDSGPPTLFPFATLPLGINITYFQVIP---SSI----RSTQ 216
                          250       260       270       280       290       300       310
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1796318598  257 GWTAGAAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKCTLKSFTVEKGIYQTSNFRVQPTESIV-RFPNITN 334
Cdd:pfam16451  217 NCRRANAAYYVAPLKPSTFLLDFDVNGYITNAVDCSFDPLSELKCSTGSFEPDTGVYSTSSYRAQPVGSVYvRQPNVTC 295
bCoV_S1_RBD pfam09408
Betacoronavirus spike glycoprotein S1, receptor binding; This entry represents the receptor ...
348-502 1.04e-43

Betacoronavirus spike glycoprotein S1, receptor binding; This entry represents the receptor binding domain (S1 RBD) of the betacoronavirus spike glycoprotein. The spike glycoprotein is arranged in trimers on the surface of the viral membrane and is essential for viral entry. The spike protein is translated as a large polypeptide that is subsequently cleaved to the distal S1, responsible for receptor binding, and the membrane-anchored S2 responsible for membrane fusion. The coronavirus (SARS-CoV) S1 subunit is composed of two distinct domains: an N-terminal domain (S1 NTD) and a receptor-binding domain (S1 RBD) also referred to as the S1 CTD or domain B. Each of these domains have been implicated in binding to host receptors. However, most coronaviruses are not known to utilize both the S1 NTD and S1 RBD for viral entry. SARS-CoV makes use of its S1 RBD to bind to the human angiotensin-converting enzyme 2 (ACE2) as its host receptor.


Pssm-ID: 462789  Cd Length: 156  Bit Score: 156.12  E-value: 1.04e-43
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  348 ASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADSFVIRGDEVRQIAPGQTGKIADYNYKLPD 427
Cdd:pfam09408    1 PSPANWERKTFSNCNFDFSVLLSLLQVSSFKCYGVSPSKLADMCYGSVTIDYFAIPETHKSNLQPGSPGAISKYNYKLPD 80
                           90       100       110       120       130       140       150
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1796318598  428 DFTGCVIAWNSNNLDSkVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGSTPCNgvegFNCYFPLQSYGFQPTNG 502
Cdd:pfam09408   81 DFYGCVLAFNVNANTN-YAFADNYPYRYIKPGQYQPCNSFVSTVPNSPDGHYCT----PSSFNGVVVITLKPATG 150
 
Name Accession Description Interval E-value
SARS-CoV-like_Spike_SD1-2_S1-S2_S2 cd22378
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
543-1208 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from SARS-CoV-2 (COVID-19) and related betacoronaviruses in the B lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the sarbecovirus subgenus (B lineage), including highly pathogenic human CoVs such as Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS-CoV-2 (also known as a 2019 novel coronavirus or 2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. Notably, SARS-CoV-2 has a functional polybasic (furin) cleavage site through the insertion of PRRAR*SV (* indicates the cleavage site) at the S1/S2 interface, which is absent in SARS-CoV and other SARS-related coronaviruses. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411965 [Multi-domain]  Cd Length: 662  Bit Score: 1400.89  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  543 FNGLTGTGVLTESNKKFLPFQQFGRDIADTTDAVRDPQTLEILDITPCSFGGVSVITPGTNTSNQVAVLYQDVNCTEVPV 622
Cdd:cd22378      1 FNGLTGTGVLTPSSKRFQPFQQFGRDVSDFTDSVRDPKTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  623 AIHADQLTPTWRVYSTGSNVFQTRAGCLIGAEHVNNSYECDIPIGAGICASYQTQTnsprRARSVASQSIIAYTMSLGAE 702
Cdd:cd22378     81 AIHADQLTPAWRVYSTGSNVFQTQAGCLIGAEHVNTSYECDIPIGAGICASYHTVS----LLRSTSQKSIVAYTMSLGAE 156
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  703 NSVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVF 782
Cdd:cd22378    157 NSIAYSNNSIAIPTNFSISVTTEVMPVSMAKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALSGIAVEQDKNTQEVF 236
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  783 AQVKQIYKTPPIKDFGGFNFSQILPDPSKPSKRSFIEDLLFNKVTLADAGFIKQYGDCLGDIAARDLICAQKFNGLTVLP 862
Cdd:cd22378    237 AQVKQMYKTPTIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDINARDLICAQKFNGLTVLP 316
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  863 PLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTA 942
Cdd:cd22378    317 PLLTDEMIAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKQIANQFNKAISQIQESLTTTS 396
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  943 SALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASA 1022
Cdd:cd22378    397 TALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASA 476
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1023 NLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGKAHFPREGVFVSNGTHW 1102
Cdd:cd22378    477 NLAATKMSECVLGQSKRVDFCGKGYHLMSFPQAAPHGVVFLHVTYVPSQERNFTTAPAICHEGKAYFPREGVFVSNGTSW 556
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1103 FVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKE 1182
Cdd:cd22378    557 FITQRNFYSPQIITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKE 636
                          650       660
                   ....*....|....*....|....*.
gi 1796318598 1183 IDRLNEVAKNLNESLIDLQELGKYEQ 1208
Cdd:cd22378    637 IDRLNEVAKNLNESLIDLQELGKYEQ 662
betaCoV_Spike_SD1-2_S1-S2_S2 cd22370
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
543-1203 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses; This family contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses, including three highly pathogenic human coronaviruses (CoVs), Middle East respiratory syndrome coronavirus (MERS-CoV), Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS coronavirus 2 (SARS-CoV-2), also known as a 2019 novel coronavirus (2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411957 [Multi-domain]  Cd Length: 667  Bit Score: 1112.55  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  543 FNGLTGTGVLTESNKKFLPFQQFGRDIADTTDAVRDPQTLEILDITPCSFGGVSVITPGTNTsNQVAVLYQDVNCTEVPV 622
Cdd:cd22370      1 LYGYTGTGVLTETNATFLPFQNFGYDSNGNLIAFKDPQTNTIYTILPCVSGPVSVITPGNNT-NEVAVLYNGLNCSEVPS 79
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  623 AIHADQLTPTWRVYSTGSNVFQTRAGCLIGAE-HVNNSYECDIPIGAGICASYQTQTNSPRRarSVASQSIIAYTMSLGA 701
Cdd:cd22370     80 AISAVSLTPWWRVYSSTSNYFDTPVGCLLGAVnSSNNSYECDLPLGAGLCASYTTQSVLRSR--SVASRSIRLTTMSFFA 157
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  702 EN----SVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKN 777
Cdd:cd22370    158 ENsvdvEVAYSNFSIQIPTNFTIAVTEEFIPTTMPKVTVDCAQYVCGDSSECSNLLLQYGTFCDNINRALTGVALLQDKN 237
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  778 TQEVFAQVKQIYKTP-PIKDFGGFNFSQILPDPS---KPSKRSFIEDLLFNKVTLADAGFIKQYGDCLGDIAARDLICAQ 853
Cdd:cd22370    238 QLEVFASVKQIVKTPaPLKDFGGFNFSSLLPCLGsngGSSARSAIEDLLFNKVTLADVGFMKQYDDCTGGSAARDLICAQ 317
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  854 KFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGK 933
Cdd:cd22370    318 SFNGLKVLPPLLTDEMIAAYTSALLGGTATSGWTFGASSAAQIPFAMQMAYRFNGIGVTQQVLVENQKLIANKFNQALGS 397
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  934 IQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLI 1013
Cdd:cd22370    398 IQTGFTATNSALAKLQDVVNQNAQALNTLVKQLSNNFGAISSSLNDILSRLDKLEADVQIDRLINGRLQVLQTYVTQQLI 477
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1014 RAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGKAHFPREG 1093
Cdd:cd22370    478 RASEIRASAQLAAQKMSECVKGQSKRVDFCGNGTHLMSFPQSAPNGVVFLHVTYKPTSYKNVTTAPAICHNGKAYFPKEG 557
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1094 VFVSNGTHWFVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGIN 1173
Cdd:cd22370    558 VFVKNNNSWMFTGRNFYEPEIITTDNTFYSGSCDVNFTYVNNTVYNPLQPELDDFKAELDKFFKNHTSPDPNLGDLSGIN 637
                          650       660       670
                   ....*....|....*....|....*....|
gi 1796318598 1174 ASVVNIQKEIDRLNEVAKNLNESLIDLQEL 1203
Cdd:cd22370    638 ASFVDLQKEMDTLQEVVKQLNESLIDLKEL 667
CoV_Spike_S1-S2_S2 cd21698
S1/S2 cleavage region and the S2 fusion subunit of coronavirus spike (S) proteins; This model ...
667-1203 0e+00

S1/S2 cleavage region and the S2 fusion subunit of coronavirus spike (S) proteins; This model represents the S1/S2 cleavage region and the S2 subunit of the spike (S) glycoprotein from coronavirus (CoVs), including three highly pathogenic human CoVs, Middle East respiratory syndrome coronavirus (MERS-CoV), Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS coronavirus 2 (SARS-CoV-2), also known as a 2019 novel coronavirus (2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect S1 and S2. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV, and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP), and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. Notably, SARS-CoV-2 has a functional polybasic (furin) cleavage site through the insertion of PRRAR*SV (* indicates the cleavage site) at the S1/S2 interface, which is absent in SARS-CoV and other SARS-related CoVs. The S1/S2 cleavage region and the S2 fusion subunit play an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411955 [Multi-domain]  Cd Length: 523  Bit Score: 769.66  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  667 GAGICASYQtqtnsprrarsvasqsIIAYTMSLGAENS---VAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYIC 743
Cdd:cd21698      1 YGGICICYD----------------GAIYTVSTGQEESpsiVAISTENIAIPSNFTLSVTTEYLQVTMTKVSVDCTTYVC 64
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  744 GDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVFAQVKQIYKTPPIKDFGGFNFSQILPDPSKPSKRSFIEDLLF 823
Cdd:cd21698     65 GGSPRCKNLLLQYGSACDTIEQALRGIAVLEDSEVSNMFSTSKQALKLAIIKSFGGFNFSQILPTPSRPSGRSAIEDLLF 144
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  824 NKVTLADAGFIKQYGDCLGDIAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGwtfgAGAALQIPFAMQMA 903
Cdd:cd21698    145 TKVVTAGLGTVDQYKNCTKGIAIADLACAQYYNGIMVLPPVADAEKMAMYTGSLTAGMVFGG----ITAAAAIPFSLAMQ 220
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  904 YRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSR 983
Cdd:cd21698    221 ARLNYVGLQQNVLLENQKLLANSFNKAIGNISDAFSSTSSALQKIQDVVNQQAQALNTLTSQLSNNFGAISSSIQDIYQR 300
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  984 LDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFL 1063
Cdd:cd21698    301 LDKLEADVQVDRLITGRLAALNAFVTQQLIKAAEVRQSRRLAQQKINECVKSQSSRYGFCGNGTHLFSIPQSAPSGIVFL 380
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1064 HVTYVPAQEKNFTTAPAICHDGKAHFPRE--GVFVSNGTHWFVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTV-YDP 1140
Cdd:cd21698    381 HTVLVPTSYKNVTAYPGICVDGKAGSPLEgpLVFIQNNNHWFVTPRNMYEPRIITTADFVQITSCDANVTIVNNTVnLDP 460
                          490       500       510       520       530       540
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1796318598 1141 LQPELDSFKEELDKYF---KNHTSPDVDLGdisGINASVVNIQKEIDRLNEVAKNLNESLIDLQEL 1203
Cdd:cd21698    461 VIPDYVDVNEELDDYIqnlPNHTLPDLDLS---GYNATILNISSEIDRLNEVAKNLNQSVVELQEY 523
CoV_S2 pfam01601
Coronavirus spike glycoprotein S2; The coronavirus spike glycoprotein forms the characteriztic ...
710-1211 0e+00

Coronavirus spike glycoprotein S2; The coronavirus spike glycoprotein forms the characteriztic 'corona' after which the group is named. The Spike glycoprotein is translated as a large polypeptide that is subsequently cleaved to S1 pfam01600 and S2,. The S2 subunit normally contains multiple key components, including one or more fusion peptides (FP), a second proteolytic site (S2') and two conserved heptad repeats (HRs), driving membrane penetration and virus-cell fusion. The HRs can trimerize into a coiled-coil structure built of three HR1-HR2 helical hairpins presenting as a canonical six-helix bundle and drag the virus envelope and the host cell bilayer into close proximity, preparing for fusion to occur.


Pssm-ID: 460263  Cd Length: 502  Bit Score: 661.66  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  710 NSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVFAQVKQIY 789
Cdd:pfam01601    1 GNISIPTNFTISVQTEYIQTTSPKVSVDCAQYVCNGNERCLQLLVQYGSFCSTIEQALQGSARLEDVEVLSMLSISNRAL 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  790 KTPPIKDFGG-FNFSQILPDPskPSKRSFIEDLLFNKVTLADAGFIKQYGDCLGDIAARDLICAQKFNGLTVLPPLLTDE 868
Cdd:pfam01601   81 TLATISNFGSdFNFSSFLPCL--NSGRSAIEDLLFDKVVTSGLGTVDAYKKCTKGTSIADLVCAQYYNGIMVLPGVVDAE 158
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  869 MIAQYTSALLAGTITSGWTFGAGAalqIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTASALGKL 948
Cdd:pfam01601  159 KMAMYTASLTGGMAFGGLTGAAAA---IPFALAVQARLNYLGLQTDVLQENQKILANAFNNAVGNITDGFTTTASALSKI 235
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  949 QDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATK 1028
Cdd:pfam01601  236 QDVVNANAQALNQLTQQLSNNFGAISSSIQDIYSRLDQLEADAQVDRLINGRLAALNAFVTQQLTKASEVKASRQLAQQK 315
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1029 MSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGK-AHFPREGVFVSNGTH-WFVTQ 1106
Cdd:pfam01601  316 VNECVKSQSSRYGFCGNGTHLFSLPQAAPNGIMFLHTVLVPTEYITVKATPGLCVNGTtGYAPRDGQFVLNNTSnWYITP 395
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1107 RNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLgDISGINASVVNIQKEI--- 1183
Cdd:pfam01601  396 RNMYQPRPITGSDFVQISSCDVNFVNITNTKLPPLIPDYVDFNKELEDIYKNLNSTLPDL-DLDIFNATILNLTDEIkdl 474
                          490       500
                   ....*....|....*....|....*...
gi 1796318598 1184 DRLNEVAKNLNESLIDLQELGKYEQYIK 1211
Cdd:pfam01601  475 ERLQELIDNLNQTLVDLEWLNRYETYIK 502
bat-HKU9-CoV-like_Spike_SD1-2_S1-S2_S2 cd22381
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
543-1244 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Rousettus bat coronavirus HKU9 and related betacoronaviruses in the D lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the nobecovirus subgenus (D lineage), including Rousettus bat coronavirus HKU9 (Ro-BatCoV HKU9). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411968 [Multi-domain]  Cd Length: 731  Bit Score: 604.44  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  543 FNGLTGTGVLTESNKKFLPFQQFGRDIADTTDAVRDPQTleILDITPCSFGGVSVitpGTNTSNQVAVLYQDVNCTEVPV 622
Cdd:cd22381      1 LYGYTGTGVLSTSNLTIPDSKVFSASSTGDIIAVSVNGT--VYSISPCVSVPISV---GYDPGFERALLFNGLSCSERAR 75
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  623 AIhADQLTPTWR--VYSTGSNVFQTRAGCLIGAEHVNNSY--ECDIPIGAGICasYQTQTNSPRRARSVASQSIIAYTMS 698
Cdd:cd22381     76 AV-SEPASDYWRasVSDGANNTFDTPSGCVYNVINRTTITvnQCSMPLGNSLC--LVNNTTAVSARGSLSLLSLVTYDPL 152
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  699 LGAENSVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNT 778
Cdd:cd22381    153 YDSSVTPLTPVYWVSIPTNFTLAATTEYIQTTAPKINIDCAKYLCGDSSRCLTVLLQYGTFCDDVNKALARVSTILDASL 232
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  779 QEVFAQVKQiyKTPPIKDF---GGFNFSQIL----PDPSKPSKRSFIEDLLFNKVTLADAGFIKQYGDCL-----GDIaa 846
Cdd:cd22381    233 VSLVSELTS--DVVRSENLafdGDYNFTGLMgclgSNCNSKSYRSALSDLLYNKVKVADPGFMQSYQKCIdsqwgGNI-- 308
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  847 RDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQ 926
Cdd:cd22381    309 RDLICTQTFNGISVLPPIVSPGMQALYTSLLVGAVASSGYTFGITSVGVIPFATQLQFRLNGLGVTTQVLVENQKLIANS 388
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  927 FNSAIGKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQT 1006
Cdd:cd22381    389 FNKALVSIQKGFDATNQALSKMQTVINQHAQQLQTLVQQLGNSFGAISSSINEIFSRLDGLEANAEVDRLINGRMVVLNT 468
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1007 YVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGK 1086
Cdd:cd22381    469 YVTQLLIQASEVRAQAALAKQKISECVKAQSLRNDFCGNGTHVLSIPQLAPNGVLFIHYSYQPTAYALVQTAAGLCFNGT 548
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1087 AHFPREGVFV--SNGTHWFVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDV 1164
Cdd:cd22381    549 GYAPRGGLFVlpNNSNLWHFTKMNFYNPVNISYSNTQVLTSCSVNYTTVNYTVLNPSEPSDFNFQEEFDKWYKNQSSQFN 628
                          650       660       670       680       690       700       710       720
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1165 DLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIKWPWYIWLGFIAGLIAIVMVTIMLCCMTSCCSCL 1244
Cdd:cd22381    629 NTFNPSDFNFSTVDVNEQLATLTDVVKQLNESFIDLKKLNVYEQTIKWPWYVWLAMIAGLVGLALAVVMLLCMTNCCSCF 708
SARS-CoV-2_Spike_S1_RBD cd21480
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome coronavirus 2 ...
319-541 7.24e-166

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome coronavirus 2 Spike (S) protein; This group contains the receptor-binding domain of the S1 subunit of the spike (S) protein from highly pathogenic human virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV). The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While RBD of mouse hepatitis virus (MHV) is located at the NTD, most of other CoVs, including SARS-CoV-2 use the C-domain to bind their receptors. Recent studies found that the receptor-binding domain (RBD) of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV-2 and most CoVs.


Pssm-ID: 394827  Cd Length: 223  Bit Score: 492.30  E-value: 7.24e-166
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  319 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 398
Cdd:cd21480      1 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  399 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGST 478
Cdd:cd21480     81 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGST 160
                          170       180       190       200       210       220
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1796318598  479 PCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 541
Cdd:cd21480    161 PCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 223
MERS-CoV-like_Spike_SD1-2_S1-S2_S2 cd22379
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
544-1211 8.00e-165

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Middle East respiratory syndrome coronavirus and related betacoronaviruses in the C lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the merbecovirus subgenus (C lineage), including Middle East respiratory syndrome coronavirus (MERS-CoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411966 [Multi-domain]  Cd Length: 682  Bit Score: 507.41  E-value: 8.00e-165
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  544 NGLTGTGVLTESNKKFLPFQQFGRDIADTTDAVRDPQTlEILDITPCSFGGVSVITpgTNTSNQVAVLYQDVNCTEVPVA 623
Cdd:cd22379      2 YGVTGRGVFQNCTAVGIRQQRFVYDSFDNLVGYHSDDG-NYYCVRPCVSVPVSVIY--DKSTNTHATLFGSVACEHISTM 78
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  624 IHA-DQLTPTWRVYSTGSNVFQTRAGCLIGAehVNNSY---ECDIPIGAGICASYQTQTNSPRRARSVASQSIIAYT--M 697
Cdd:cd22379     79 MSQfSRSTQSMLRRRSTNGPLQTAVGCVIGL--VNTSLtveDCKLPLGQSLCAVPPTLTPRSVSSVPGEQLASINFNhpL 156
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  698 SLGAENSvaySNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKN 777
Cdd:cd22379    157 QVDQLNS---SGFKVSIPTNFSFGVTQEYIQTTIQKVTVDCKQYVCNGFEKCEQLLREYGQFCSKINQALHGANLRQDDS 233
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  778 TQEVFAQVKQIYKTPPIKDFGG-FNFSQILP---DPSKPSKRSFIEDLLFNKVTLADAGFIKQYGDCL--GDIAARDLIC 851
Cdd:cd22379    234 VRNLFASIKTSQSQPLIAGLGGdFNLTLLEPpsiSTGSRSYRSAIEDLLFDKVTIADPGYMQGYDECMkqGPPSARDLIC 313
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  852 AQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAI 931
Cdd:cd22379    314 AQYVAGYKVLPPLYDVNMEAAYTSSLLGSIAGAGWTAGLSSFAAIPFAQSIFYRLNGVGITQQVLSENQKLIANKFNQAL 393
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  932 GKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQ 1011
Cdd:cd22379    394 GAMQTGFTTTNLAFQKVQDAVNANAQALSKLASELSNTFGAISSSIGDILKRLDVLEQEAQIDRLINGRLTSLNAFVAQQ 473
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1012 LIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDG---KAH 1088
Cdd:cd22379    474 LVRSETAARSAQLAKDKVNECVKSQSKRNGFCGQGTHIVSFVINAPNGLYFFHVGYVPTNHVNVTAAYGLCDSAnptNCI 553
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1089 FPREGVFVSNGT-----HWFVTQRNFYEPQIITTDNT-FVSGncDVVIGIVNNTVYDPL---QPELDsFKEELDKYFKNH 1159
Cdd:cd22379    554 APVNGYFIKNNTtrivdEWSYTGSSFYAPEPITSANTrYVSP--DVTFQNLSNNLPPPLlsnSTDID-FKDELEEFFKNV 630
                          650       660       670       680       690
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1796318598 1160 TSPDVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIK 1211
Cdd:cd22379    631 SSQIPNFGSISQINTTLLDLSDEMLSLQQVVKALNESYIDLKELGNYTYYQK 682
SARS-CoV-like_Spike_S1_NTD cd21624
N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory ...
13-304 4.14e-152

N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory syndrome coronavirus and related betacoronaviruses in the B lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the sarbecovirus subgenera (B lineage), including the highly pathogenic human coronavirus (CoV), Severe acute respiratory syndrome (SARS) CoV, and SARS-CoV-2, also known as a 2019 novel coronavirus (2019-nCoV) or COVID-19 virus. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2 and SARS-CoV, use the C-domain to bind their receptors. The S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394950  Cd Length: 280  Bit Score: 458.34  E-value: 4.14e-152
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   13 SQCVNLTTRTQLPPAYTNSFTRGVYYPDKVFRSSVLHSTQDLFLPFFSNVTWFHAIHVSGtNGTKRFDNPVLPFNDGVYF 92
Cdd:cd21624      1 EGCTTFSDKTAPNMTQYSSSRRGVYYPDDIFRSDVLVLTQDYFLPFNSNVTWYHSLNALG-ERKYYFDNPVLPFGDGVYF 79
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   93 ASTEKSNIIRGWIFGTTLDSKTQSLLIVNNATNVVIKVCEFQFCNDPFLGVYYHknnksWMESEFRVYSSANNCTFEYVS 172
Cdd:cd21624     80 AATEKSNVVRGWIFGSTFDNTSQSAIIVNNGTHIIIRVCNFQLCKNPMFAVSKP-----GTQTNSWIYSNAFNCTYEYVS 154
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  173 QPFLMDLEGKQGNFKNLREFVFKNIDGYFKIYSKHTPINLVRDLPQGFSALEPLVDLPIGINITRFQTLLALHRSYLtpg 252
Cdd:cd21624    155 QSFQLDVSEKNGNFKHLREFVFKNVDGFLKVYHGYQPINVVRGLPSGFSVLKPIFKLPLGINITNFRVVLTMFSPAQ--- 231
                          250       260       270       280       290
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1796318598  253 dssSGWTAGAAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKCTLK 304
Cdd:cd21624    232 ---SNWTAGNAAYYVGYLKPTTFMLKFDENGTITDAVDCSQDPLAELKCTLK 280
HKU1-CoV-like_Spike_SD1-2_S1-S2_S2 cd22380
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
545-1203 8.24e-150

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from human HKU1 and OC43 coronaviruses and related betacoronaviruses in the A lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the embecovirus subgenus (A lineage), including highly pathogenic human coronaviruses (CoVs), HKU1 and OC43 CoVs, as well as murine hepatitis virus (MHV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of MHV is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411967 [Multi-domain]  Cd Length: 663  Bit Score: 467.33  E-value: 8.24e-150
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  545 GLTGTGVLTESNKKFL-PFQQFGRDIADTTDAVRDPQTLEILDITPCSFGGVSVITpgTNTSNQVAVLYQDVNCTEVPVA 623
Cdd:cd22380      3 GITGQGIFKEVNADYYnSWQNLLYDSNGNLYGFRDYLTNKTYMIRSCYSGRVSAAF--HANASEPALLYRNLKCSYVFNN 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  624 IHADQLTPTwrvystgsNVFQTRAGCLIGAEHVNNSY--ECDIPIGAGICASYQTQtnspRRARSVASQSiiaYTMSLGA 701
Cdd:cd22380     81 TISREEQPL--------NYFDSYLGCVVNADNSTSSAvqTCDLRMGSGYCVDYSTS----RRSRRSISTG---YRFTTFE 145
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  702 ENSVAYSNNS---------IAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAV 772
Cdd:cd22380    146 PFTVNLVNDSvepvgglyeIQIPTNFTIGNHEEFIQTSSPKVTIDCAAFVCGDYAACRQQLVEYGSFCDNINAILNEVNE 225
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  773 EQDKNTQEVFAQVKQ-IYKTPPIKDFGGF-----NFSQIL----PDPSKPSKRSFIEDLLFNKVTLADAGFIKQYGDCLG 842
Cdd:cd22380    226 LLDTTQLQVANSLMQgVTLSSRLKDGINFnvddiNFSPVLgclgSDCNAASSRSAIEDLLFDKVKLSDVGFVEAYNNCTG 305
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  843 DIAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTFGAGaalqIPFAMQMAYRFNGIGVTQNVLYENQKL 922
Cdd:cd22380    306 GAEIRDLLCVQSFNGIKVLPPVLSENQISGYTTAATAASLFPPWSAAAG----VPFSLNVQYRINGLGVTMDVLSQNQKL 381
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  923 IANQFNSAIGKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQ 1002
Cdd:cd22380    382 IANAFNNALGAIQEGFDATNSALAKIQSVVNANAEALNNLLQQLSNRFGAISASLQEILSRLDALEAQAQIDRLINGRLT 461
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1003 SLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAIC 1082
Cdd:cd22380    462 ALNAYVSQQLSDSTLVKFSAAQAIEKVNECVKSQSPRINFCGNGNHILSLVQNAPYGLYFIHFSYVPTSFVTAKVSPGLC 541
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1083 HDG-KAHFPREGVFVSNGTHWFVTQRNFYEPQIITTDNTFVSGNCDVVIG-----IVNNTVydplqPELDSFKEELDKYF 1156
Cdd:cd22380    542 IAGdRGIAPKSGYFVNVNNEWMFTGSGYYYPEPITDKNVVVMSSCAVNYTkapdvMLNTSI-----PNLPDFKEELDQWF 616
                          650       660       670       680
                   ....*....|....*....|....*....|....*....|....*..
gi 1796318598 1157 KNHTSPDVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQEL 1203
Cdd:cd22380    617 KNQTSVAPDLSLDEYINVTFLDLQDEMNRIQEAIKVLNESYINLKEI 663
alphaCoV-HKU2-like_Spike_SD1-2_S1-S2_S2 cd22371
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the CoV ...
543-1243 2.75e-144

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the CoV spike (S) glycoprotein from Rhinolophus bat coronavirus HKU2 and related alphacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Wencheng shrew coronavirus (WESV), Lucheng Rn rat coronavirus (LRNV), and two bat viruses (Rhinolophus bat coronavirus HKU2 and BtRf-AlphaCoV/YN2012). Members of this group form a distinct cluster that is separated from the other alphacoronaviruses. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411958 [Multi-domain]  Cd Length: 686  Bit Score: 453.48  E-value: 2.75e-144
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  543 FNGLTGTGVLTESNKKFLPFQqfgrDIADTTDAVRDPQTLEIL-DITPCSFGGVSVITpgtNTSNQVAVLYQDVNCTEVP 621
Cdd:cd22371      1 IDGVTFQGILYETNFTFDSFY----NLLYKGSMVKYVRILGVVyEVEPCNEFSYSVLK---NNSSSYGTLYSGADCNQID 73
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  622 vaihadqlTPTWRVYSTGSNVFQTRAGCLIGAEHVN-NSYECDIPIGAGICASYQTQTNSPRRARSVASQSiiAYTMSLG 700
Cdd:cd22371     74 --------TKTFRFKARSHTGTNTSLGCLFNASYTNdTYTTCLNPLGNGFCADVNVTSPVVGNIGIQKHDT--DYVRPIL 143
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  701 AENSvaysnnsIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQE 780
Cdd:cd22371    144 TEQF-------IELPLDHQLVVKEQFLQTSMPKFDVDCERYICDVSKACRELLFKYGGFCSKITADIKGSSILLDSQILG 216
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  781 VFAQVKQIYKTPpIKDFGGFNFSQILPdpsKPSKRSFIEDLLFNKVTLADAGFIKQYGDCLGDiAARDLICAQKFNGLTV 860
Cdd:cd22371    217 LYKTIAVDFSSP-DVDFGDFNFSMFMS---EKNGRSFIEDLLFDKIVTTGPGFYQDYYDCKKM-NLQDLTCAQYYNGIMV 291
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  861 LPPLLTDEMIAQYTSALlAGTITSGwTFGaGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSS 940
Cdd:cd22371    292 IPPIMDDETIGMYGGIV-AASMTAG-LFG-GQAGMVTWNTAMAGRLNALGVTQDALVEDVNKLANGFNNLTQSVSKLAKT 368
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  941 TASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRA 1020
Cdd:cd22371    369 TSQALSAIQAVVNQNAAQVEQLVQGLSENFGAISNNFEVIAERLEKLEADQQMDRLINGRMNVLQNFVTNYKLKISELKS 448
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1021 SANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGKAHFP----REGVFV 1096
Cdd:cd22371    449 TQRLVQSLINECVYAQSLRNGFCGDGLHVMSLMQNAPDGIMFFHYTLKPNNTIIVKTTPGLCLSNEVCIKpidaKFGVLV 528
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1097 S-NGTHWFVTQRNFYEPQIITTDNTfVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISgINAS 1175
Cdd:cd22371    529 SaNDSYWHFTPRNIYNPENITNSNI-IAVSGGANYTTVNNTIDIIEPPQNPPIDEEFRELYKNVTLELEQLKNIT-FDMS 606
                          650       660       670       680       690       700
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1796318598 1176 VVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIKWPWYIWLGFIAGLIAIVMVTIMLCCMTSCCSC 1243
Cdd:cd22371    607 KLNLTYEIDRLNEIAENVSKLHVTVSEFNKYVQYVKWPWYVWLAIFLVLILFSFLMLWCCCATGCCGC 674
gammaCoV_Spike_SD1-2_S1-S2_S2 cd22372
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
532-1203 1.91e-139

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from avian infectious bronchitis coronavirus (IBV) and related gammacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from gammacoronaviruses, including avian infectious bronchitis virus, and Beluga whale coronavirus SW1 (whale-CoV SW1). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411959 [Multi-domain]  Cd Length: 661  Bit Score: 439.81  E-value: 1.91e-139
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  532 NLVKNKCVNFNFNGLTGTGVLTesnkkflpfqqfgrdiaDTTDAVRDPQTLE-----ILDitpcSFGGVSVItpgtNTSN 606
Cdd:cd22372      3 NITLNKCVDYNIYGRVGQGFIT-----------------NVTDSAADYNYLAdgglaILD----TSGAIDIF----VVQG 57
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  607 QVAVLYQDVN-CTEVpvaihADQLtptwrVYSTGSNVfqtraGCLI-----GAEHVNNSYecdipigagicasYQTQTNS 680
Cdd:cd22372     58 EYGLNYYKVNpCEDV-----NQQF-----VVSGGNLV-----GILTsrnetGSQLLENQF-------------YIKLTNG 109
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  681 PRRARSVASQSI------------------IAYTMSLGAENSVAYSNN---SIAIPTNFTISVTTEILPVSMTKTSVDCT 739
Cdd:cd22372    110 TRRRRRSISENVtscpyvsygkfcikpdgsISTIVPQELETFVAPLLNvteNVLIPNSFNLTVTDEYIQTRMDKVQINCL 189
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  740 MYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVFAQVKQIYKTPPI---KDFGGFNFSQILPDPSKPSKRS 816
Cdd:cd22372    190 QYVCGNSLECRKLFQQYGPVCDNILSIVNSVNQKEDMELLSFYSSTKPGGFNTPVfnnVSTGGFNISLLLPPPSSPQGRS 269
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  817 FIEDLLFNKVTLADAGFIKQYGDC----LGdiAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTfGAGA 892
Cdd:cd22372    270 FIEDLLFTKVETVGLPTDDAYKKCtagpLG--FLKDLVCAQEYNGLLVLPPIITAEMQTMYTGSLVASMAFGGIT-AAGA 346
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  893 alqIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGA 972
Cdd:cd22372    347 ---IPFATQIQARINHLGITQSLLLKNQEKIAASFNKAIGHMQEGFRSTSLALQQIQDVVNKQSAILTETMASLNKNFGA 423
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  973 ISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSF 1052
Cdd:cd22372    424 ISSVIQDIYQQLDAIQADAQVDRLITGRLSSLSVLASAKQAEYYKVSQQRELATQKINECVKSQSNRYGFCGNGRHVLTI 503
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1053 PQSAPHGVVFLHVTYVPAQEKNFTTAPAIC-----HDGKAHFPR--EGVFVS-NGThWFVTQRNFYEPQIITTDNTFVSG 1124
Cdd:cd22372    504 PQNAPNGIVFIHFTYTPESFVNVTAIVGFCvnpanGSQYAIVPAngRGIFIQvNGT-YYITARDMYMPRDITAGDIVTLT 582
                          650       660       670       680       690       700       710       720
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1125 NCDVVIGIVNNTVYDPL-QPELDSFKEELDKYFkNHTSPdvDLGDISGINASVV--NIQKEIDRLNEVAKNLNESLIDLQ 1201
Cdd:cd22372    583 SCQANYVSVNKTVITTFvDNDDFDFDDELSKWW-NETKH--ELPDFDQFNYTIPilNISNEIDRIQEVIQGLNDSLIDLE 659

                   ..
gi 1796318598 1202 EL 1203
Cdd:cd22372    660 TL 661
SARS-CoV-like_Spike_S1_RBD cd21477
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related ...
319-541 4.09e-136

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related coronavirus Spike (S) protein and similar proteins; This subfamily contains the receptor-binding domain of the S1 subunit of coronavirus (CoV) spike (S) proteins from highly pathogenic human virus, severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), SARS coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV), and other SARS-like coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2 and SARS-CoV use the C-domain to bind their receptors. Recent studies found that the receptor-binding domain (RBD) of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV, SARS-CoV-2, and most CoVs.


Pssm-ID: 394824  Cd Length: 205  Bit Score: 413.44  E-value: 4.09e-136
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  319 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 398
Cdd:cd21477      1 RVSPTTEVVRFPNITNLCPFDKVFNATRFPSVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  399 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNldskvGGNYNYLYRLFRKSNLKPFERDISTEIYqagst 478
Cdd:cd21477     81 TFLIRGSEVRQVAPGQTGVIADYNYKLPDDFTGCVIAWNTAK-----QDNGNYYYRSHRKSKLKPFERDLSSDEN----- 150
                          170       180       190       200       210       220
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1796318598  479 pcngvegfNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 541
Cdd:cd21477    151 --------SGVRTLSTYDFNPTVPVGYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 205
alphaCoV_Spike_SD1-2_S1-S2_S2 cd22369
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
532-1203 2.67e-126

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) protein from alphacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from alphacoronaviruses including human coronaviruses (HCoVs), HCoV-NL63, and HCoV-229E, and porcine coronaviruses, transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV), among others. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP), and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1 the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411956 [Multi-domain]  Cd Length: 666  Bit Score: 404.75  E-value: 2.67e-126
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  532 NLVKNKCVNFNFNGLTGTGVLTESNKKFLPfQQFGRDIADTTDAVRDPQTLEILDITPCsfggvsvitpgtNTSNQVAVL 611
Cdd:cd22369      4 VVHLNVCTDYTIYGITGRGIIRKSNSTYIA-GLYYTSNSGQLLGFKNSTTGEVFSVTPC------------QLSSQVAVV 70
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  612 YQDVncteVPVAIHADQLTPTWRVYSTGSNVFQtragcligaeHVNNSYECDIPI----GAGICASYQTQTNSPRRARSV 687
Cdd:cd22369     71 SDNI----VGVMSATNNVSLGFNNTIETPSFYY----------HSNGAENCTEPVltygSIGVCADGSITEVTPRSVSPE 136
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  688 ASQSIIaytmslgaensvaySNNsIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCT------ 761
Cdd:cd22369    137 PVSPII--------------TGN-ISIPSNFTVSVQVEYLQMYLKPVSVDCSTYVCNGNPRCLQLLTQYASACRtieeal 201
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  762 QLNRALTGIAVEQDKNTQEVFAQVKQIYKTppikdFGGFNFSQILPdpSKPSKRSFIEDLLFNKVTLADAGFIKQ-YGDC 840
Cdd:cd22369    202 QLSARLESVEVNSMITVSEEALRLANISTF-----FDDYNLSAVLP--AGVGGRSAIEDLLFDKVVTSGLGTVDEdYKAC 274
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  841 LGD--IAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGwtFGAGAAlqIPFAMQMAYRFNGIGVTQNVLYE 918
Cdd:cd22369    275 TKGlgIAAADVACAQYYNGIMVLPGVVDAEKMALYTASLTGGMVLGG--FTAAAA--IPFSLAVQSRLNYVALQTDVLQR 350
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  919 NQKLIANQFNSAIGKI--------------QDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRL 984
Cdd:cd22369    351 NQQILANSFNSAMGNItvafsevndaiqqtSDAINTVAQALNKVQNVVNEQGQALSQLTKQLASNFQAISSSIEDIYNRL 430
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  985 DKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLH 1064
Cdd:cd22369    431 DGLAADAQVDRLITGRLAALNAFVTQTLTKYTEVRASRQLAQQKINECVKSQSSRYGFCGNGTHLFSIVNAAPDGIMFLH 510
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1065 VTYVPAQEKNFTTAPAICHDGKAHFPREGV---FVSNGTHWFVTQRNFYEPQIITTDNtFVS-GNCDVVIgiVNNTVYD- 1139
Cdd:cd22369    511 TVLLPTEYVTVAAWAGLCVDGKAYVLRDDVvltLFKLNDKYYVTPRDMFEPRVPVSSD-FVQiSNCNVTY--VNITSDEl 587
                          650       660       670       680       690       700       710       720
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1140 -PLQPE-LDSFK--EELDKYFKNHTSPDVDLgDIsgINASVVNIQKEID--------------RLNEVAKNLNESLIDLQ 1201
Cdd:cd22369    588 pEVIPDyIDVNKtlEEFLANLPNYTLPDLPL-DI--FNATYLNLTGEIAdlenksesllnttvELQELIDNINNTLVDLE 664

                   ..
gi 1796318598 1202 EL 1203
Cdd:cd22369    665 WL 666
delta-PiCoV-like_Spike_SD1-2_S1-S2_S2 cd22374
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
536-1241 3.61e-122

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Pigeon coronavirus UAE-HKU29, and related avian deltacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Pigeon coronavirus UAE-HKU29, and related avian deltacoronaviruses including Falcon coronavirus UAE-HKU27, Magpie-robin coronavirus HKU18, Sparrow coronavirus HKU17, and Night heron coronavirus HKU19. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the (C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411961 [Multi-domain]  Cd Length: 739  Bit Score: 396.18  E-value: 3.61e-122
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  536 NKCVNFNFNGLTGTGVLTESNKKFLPFQQFGRDIADTTdAVRDPQTLEILDITPCSFggvsvitpgtntSNQVAVLYQDV 615
Cdd:cd22374     26 DVCTKYNIYGKTGTGIIRLTNQSYIAGLYYTSPSGDLL-AFKNVTTQTVYSVTPCRL------------SSQVAVYNGSI 92
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  616 nctevpvaIHAdqLTPTWRVYSTgSNVFQTRAGCLIgaEHVNNSYECDIPI----GAGICASyqtqtnsprrarsvaSQS 691
Cdd:cd22374     93 --------IAA--FTSTENFTIA-DFTYSRATPMFY--YHSIGNDTCETPVitfgSIGVCPG---------------GGL 144
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  692 IIAYTMSLGAENSVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIA 771
Cdd:cd22374    145 HFVDPTSNEFTNVVPISTQNISIPKNFTVSIQTEYIQIEQQPVTVDCRQYVCNGNPRCLQLLMQYTSACSTIEQALSLNA 224
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  772 VEQDKNTQEVFAQVKQIYKTPPIKDFG----GFNFSQILPdpSKPSKRSFIEDLLFNKVTLADAGFIKQ-YGDCLGDIAA 846
Cdd:cd22374    225 RLEAASIQTMLTYSPETLKLANITNFQsddvNYNLTNILP--KKYQGRSAIEDLLFDKVVTNGLGTVDQdYKACTNGVSI 302
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  847 RDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTfgagAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQ 926
Cdd:cd22374    303 ADLVCAQYYNGIMVLPGVADPEKMAQYTASLTGGMVFGGLT----SAAAIPFSLAVQSRLNYVALQTDVLQQNQQILADS 378
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  927 FNSAIGKI--------------QDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQ 992
Cdd:cd22374    379 FNNAMGNItlafkevseglsqvSGAITTVANALTKIQTVVNSQGQALATLTEQLANNFQAISASIADIYNRLNQLEADAQ 458
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  993 IDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQE 1072
Cdd:cd22374    459 VDRLITGRLAALNAFVTQTLSKLAEVRQARQLALDKINECVKSQSSRYGFCGNGTHLFSIVNAAPYGFVFFHTVLLPTQY 538
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1073 KNFTTAPAICHDGKAHFPREG--VFVSNGTHWFVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPE---LDS 1147
Cdd:cd22374    539 ATVQAYSGICQNGRALALKDPslALFRGTDKYLVTPRNMYQPRTAAQADFVYIESCTVTYLNLTDTTIDAVIPDyvdVNK 618
                          650       660       670       680       690       700       710       720
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1148 FKEELDKYFKNHTSPDVDLG-----------DISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIKWPWYI 1216
Cdd:cd22374    619 TVEDILNNLPNYTKPDLDIGrynntilnlttEINDLNGRAENLSQIVENLEEYIKKINATLVDLEWLNRVETYIKWPWWV 698
                          730       740
                   ....*....|....*....|....*..
gi 1796318598 1217 WLGFIAGLIAIV--MVTIMLCcmTSCC 1241
Cdd:cd22374    699 WLLIALAITAFVciLVTIFLC--TGCC 723
TGEV-like_Spike_SD1-2_S1-S2_S2 cd22377
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
531-1243 6.97e-118

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from transmissible gastroenteritis virus and related alphacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from porcine transmissible gastroenteritis virus (TGEV), canine coronavirus (CCoV), and feline coronavirus (FCoV). They display greater than 96% sequence identity and have been grouped in the same species, alphacoronavirus 1, within the Alphacoronavirus genus. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411964 [Multi-domain]  Cd Length: 751  Bit Score: 384.88  E-value: 6.97e-118
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  531 TNLVKNKCVNFNFNGLTGTGVLTESNKKFLPFQQFGRDIADTTdAVRDPQTLEILDITPCSFGG-VSVITP---GTNTSN 606
Cdd:cd22377      3 SVLVKDECTDYNIYGFQGTGIIRNTTSRLVAGLYYTSISGDLL-AFKNSTTGEIFTVVPCDLTAqAAVINDeivGAITSV 81
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  607 QVAVLYQDVNCTEVPVAIHADQLTPTWrvYSTGSNVFQTRagcligaehVNNSYECDipigagiCASYQTQTNSprrarS 686
Cdd:cd22377     82 NQTDLFEFVNHTQSRRSRRSTLGLVHT--YTMPQFYYITK---------WNNDTSTN-------CTSVITYSSF-----A 138
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  687 VASQSIIAY---TMSLGAENSVAY----SNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSF 759
Cdd:cd22377    139 ICNTGEIKYvnvTHVEIVDDSIGVikpiSTGNITIPKNFTVAVQAEYIQIQVKPVVVDCAKYVCNGNRHCLKLLTQYTSA 218
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  760 CTQLNRAL-TGIAVE----------QDKNTQevFAQVKQIYKTPPI-KDFGGFNF---SQILPdpSKPSKRSFIEDLLFN 824
Cdd:cd22377    219 CQTIENALnLGARLEslmlndmitvSDRSLE--LATVEKFNSTVLGgEKLGGFYFdglKDLLP--PRIGKRSAIEDLLFN 294
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  825 KVTLADAGFIKQ-YGDCLGDIAARDLICAQKFNGLTVLPPLLTDEMIAQYTsALLAGTITSGwtfGAGAALQIPFAMQMA 903
Cdd:cd22377    295 KVVTSGLGTVDDdYKKCSAGTDVADLVCAQYYNGIMVLPGVVDDNKMAMYT-ASLIGGMALG---SITSAVAVPFAMQVQ 370
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  904 YRFNGIGVTQNVLYENQKLIANQFNSAIGKI--------------QDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSN 969
Cdd:cd22377    371 ARLNYVALQTDVLQENQKILANAFNNAIGNItlalgkvsnaitttSDGFNTMASALTKIQSVVNQQGEALSQLTSQLQKN 450
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  970 FGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHL 1049
Cdd:cd22377    451 FQAISSSIAEIYNRLEKVEADAQVDRLITGRLAALNAYVSQTLTQYAEVKASRQLAMEKVNECVKSQSDRYGFCGNGTHL 530
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1050 MSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAIC-HDGKAHFPRE---GVFVSNGThWFVTQRNFYEPQIITTDNTFVSGN 1125
Cdd:cd22377    531 FSLVNSAPDGLLFFHTVLLPTEWEEVTAWSGICvNDTYAYVLKDfltSIFSYNGT-YMVTPRNMFQPRKPQMSDFVQITS 609
                          650       660       670       680       690       700       710       720
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1126 CDVVigIVNNTVYDPLQPELD------SFKEELDKYFKNHTSPDVDLGdISGINASVVNIQKEIDRLNEVA--------- 1190
Cdd:cd22377    610 CEVT--FLNTTYTTFQEIVIDyidinkTIADMLEQYNPNYTVPELDLQ-LEIFNQTKLNLTAEIDQLEQRAdnltniahe 686
                          730       740       750       760       770       780
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1191 -----KNLNESLIDLQELGKYEQYIKWPWYIWLgfIAGLIAIVMVTIML--CCMTSCCSC 1243
Cdd:cd22377    687 lqqyiDNLNKTLVDLEWLNRIETYVKWPWYVWL--LIGLVVVFCIPLLLfcCLSTGCCGC 744
SARS-CoV_Spike_S1_RBD cd21481
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related ...
319-541 5.81e-115

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related coronavirus Spike (S) protein; This group contains the receptor-binding domain of the S1 subunit of the spike (S) protein from severe acute respiratory syndrome-related coronavirus (SARS-CoV) and similar coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV use the C-domain to bind their receptors. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV and most CoVs.


Pssm-ID: 394828  Cd Length: 222  Bit Score: 357.85  E-value: 5.81e-115
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  319 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 398
Cdd:cd21481      1 RVVPSGDVVRFPNITNLCPFGEVFNATKFPSVYAWERKKISNCVADYSVLYNSTFFSTFKCYGVSATKLNDLCFSNVYAD 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  399 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGST 478
Cdd:cd21481     81 SFVVKGDDVRQIAPGQTGVIADYNYKLPDDFMGCVLAWNTRNIDATSTGNYNYKYRYLRHGKLRPFERDISNVPFSPDGK 160
                          170       180       190       200       210       220
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1796318598  479 PCNGvEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 541
Cdd:cd21481    161 PCTP-PALNCYWPLNDYGFYTTTGIGYQPYRVVVLSFELLNAPATVCGPKLSTDLIKNQCVNF 222
delta-PDCoV-like_Spike_SD1-2_S1-S2_S2 cd22373
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
536-1210 1.76e-110

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from porcine coronavirus HKU15, avian coronaviruses, and related deltacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from porcine coronavirus PDCoV, and several avian coronaviruses such as quail deltacoronavirus (QdCoV) UAE-HKU30, white-eye coronavirus HKU16, common moorhen coronavirus HKU21, thrush CoV HKU12, and munia CoV HKU13, all from the Buldecovirus subgenus of deltacoronaviruses. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411960 [Multi-domain]  Cd Length: 648  Bit Score: 361.46  E-value: 1.76e-110
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  536 NKCVNFNFNGLTGTGVLTESNKKfLPFQQFGRDIADTTDAVRDPQTLEILDITPCSfggvsvitpgtnTSNQVAVlyqdV 615
Cdd:cd22373      1 DVCTDYTIYGVSGTGIIKPSDLQ-LHNGIAFTSPTGELYAFKNITTGKTYQVLPCE------------TPSQLIV----I 63
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  616 NCTEVPVAIHADQ---------LTPTWRVYSTGSNVFQTRAGCLIGaehvnnsyecdiPIG----AGICASYQTQTNSPr 682
Cdd:cd22373     64 NNTIVGAITSSNStengftttiVTPTFYYSTNATSFNCTKPVLSYG------------PISvcsdGAIVGTSTLQDTRP- 130
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  683 rarsvasqSIiaytmslgaensVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQ 762
Cdd:cd22373    131 --------SI------------VSLYDGEVEIPSAFTLSVQTEYLQVQAEQVVVDCPQYVCNGNSRCLQLLAQYTSACSN 190
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  763 LNRALTGIAVEQDKNTQEVFAQVKQIYKTPPIKDF-GGFNFSQILPDpsKPSKRSFIEDLLFNKVTLADAGFIKQ-YGDC 840
Cdd:cd22373    191 IESALHSSAQLDSREITNMFQTSTQSLELANITNFkGDYNFTSILTT--KIGGRSAIEDLLFNKVVTNGLGTVDQdYKSC 268
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  841 LGDIAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTfgagAALQIPFAMQMAYRFNGIGVTQNVLYENQ 920
Cdd:cd22373    269 SKDMAIADLVCSQYYNGIMVLPGVVDAEKMAMYTGSLTGAMVFGGLT----AAAAIPFSTAVQARLNYVALQTNVLQENQ 344
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  921 KLIANQFNSAIGKIQDSLSST--------------ASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDK 986
Cdd:cd22373    345 KILAESFNQAVGNISLALSSVndaiqqtsealntvANAINKIQTVVNQQGEALSHLTAQLSNNFQAISTSIQDIYNRLDE 424
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  987 VEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVT 1066
Cdd:cd22373    425 VEANQQVDRLITGRLAALNAYVTQLLNQMSQIRQSRLLAQQKINECVKSQSSRYGFCGNGTHLFSITQAAPNGIFFMHAV 504
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1067 YVPAQEKNFTTAPAICHDGKAHF---PREGVFVSNGThWFVTQRNFYEPQIITTDNTFVSGNCDVVIgivNNTVYDPLQ- 1142
Cdd:cd22373    505 LVPTKFTRVNASAGICVDNTKGYslqPQLILYQFNNS-WRVTPRNMYEPRLPRQADFIPLTDCSVTF---YNTTAADLPn 580
                          650       660       670       680       690       700       710
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1143 --PELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQelgkyeQYI 1210
Cdd:cd22373    581 iiPDYVDVNQTVSDIIDNLPTPTPPQLDVDIYNNTILNLTQEINDLQERSKNLSQIADRLQ------QYI 644
PDEV-like_Spike_SD1-2_S1-2_S2 cd22376
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
538-1207 1.12e-101

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Porcine epidemic diarrhea virus and related alphacoronavirus; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from alphacoronaviruses, including porcine epidemic diarrhea virus (PEDV), Scotophilus bat coronavirus, and swine enteric coronavirus, among others. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1 the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411963 [Multi-domain]  Cd Length: 673  Bit Score: 338.27  E-value: 1.12e-101
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  538 CVNFNFNGLTGTGVLTESNKKFLPF-------QQFGRDIADTTDAvrdpqtleILDITPCSFggvsvitpgtntSNQVAV 610
Cdd:cd22376     10 CTKYTIYGFKGEGIITLTNSSLLGGvyytsdsGQLLAFKNVTSGA--------IYSVTPCSF------------SQQAAY 69
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  611 LYQDVnctevpVAIHADQLTPTWRVYSTGSNVFQtragcligaeHVNNSYECDIPI----GAGICASYQTQTNSPRrars 686
Cdd:cd22376     70 VDDDI------VGVISSLSNSTFNSTRELPGFFY----------HSNDGSNCTEPVlvysNIGVCKSGSIGYVPSQ---- 129
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  687 vASQSIIAYTMSlgaensvaysnNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRA 766
Cdd:cd22376    130 -SGQPKIAPMVT-----------GNISIPTNFTMSIRTEYLQLYNTPVSVDCAMYVCNGNSRCKQLLTQYTSACKTIESA 197
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  767 LTGIAVEQDKNTQEVFAQVKQIYKTPPIKDF--GGFNFSQILPdpSKPSKRSFIEDLLFNKVTLADAGFIKQ-YGDCLGD 843
Cdd:cd22376    198 LQLSARLESVEVNSMLTISEEALQLATISSFngGGYNFTNVLG--ASVQKRSFIEDLLFNKVVTNGLGTVDEdYKRCSNG 275
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  844 IAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTfgAGAALqiPFAMQMAYRFNGIGVTQNVLYENQKLI 923
Cdd:cd22376    276 LSVADLVCAQYYSGVMVLPGVVDAEKLHMYSASLIGGMVLGGIT--AAAAL--PFSYAVQARLNYVALQTDVLQRNQQLL 351
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  924 ANQFNSAIGKI------------QDS--LSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEA 989
Cdd:cd22376    352 AESFNSAIGNItsafesvkeaisQTSqgLNTVAHALTKVQDVVNSQGAALNQLTVQLQHNFQAISSSIDDIYSRLDQLSA 431
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  990 EVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCG-KGYHLMSFPQSAPHGVVFLHVTYV 1068
Cdd:cd22376    432 DAQVDRLITGRLSALNAFVAQTLTKYTEVQASRKLAQQKVNECVKSQSQRYGFCGgDGEHIFSLVQAAPQGLLFLHTVLV 511
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1069 PAQEKNFTTAPAICHDG-KAHFPREGVFVSNG-------THWFVTQRNFYEPQIITTDNTFVSGNCDVV-IGIVNNTVYD 1139
Cdd:cd22376    512 PGDFVNVTAIAGLCVDDeIALTLREPGVLFTHevltytaTEYFVSPRKMFEPRKPTVSDFVQIESCVVTyVNLTSDQLPD 591
                          650       660       670       680       690       700       710       720
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1140 PLQPELDSFK--EELDKYFKNHTSPDVDLgDIsgINASVVNIQKEI--------------DRLNEVAKNLNESLIDLQEL 1203
Cdd:cd22376    592 VIPDYIDVNKtlDEILASLPNRTGPSLPL-DV--FNATYLNLTGEIadleqrseslrnttEELRSLIYNINNTLVDLEWL 668

                   ....
gi 1796318598 1204 GKYE 1207
Cdd:cd22376    669 NRVE 672
HCoV-NL63-229E-like_Spike_SD1-2_S1-S2_S2 cd22375
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
531-1211 1.61e-101

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoproteins from HCoV-NL63, HCoV-229E, and related alphacoronavirus; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from alphacoronaviruses, including human coronaviruses (HCoVs), HCoV-NL63 and HCoV-229E. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411962 [Multi-domain]  Cd Length: 677  Bit Score: 338.03  E-value: 1.61e-101
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  531 TNLVKNKCVNFNFNGLTGTGVLTESNKKFLPFQQFGRDIADTTdAVRDPQTLEILDITPCsfggvsvitpgtNTSNQVAV 610
Cdd:cd22375      3 SNVVLNNCTKYNIYDYSGTGVIRSSNDSFIGGITYTSNSGNLL-GFKDVSTGTIYSITPC------------NPPDQVVV 69
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  611 LYQDVNCtevpvAIHADQLTptwrvySTG-SNVFQtragcLIGAEHVNN-SYECDIPI----GAGICASYQTQTNSPRRA 684
Cdd:cd22375     70 YQQAIVG-----AMLSENET------RYGlSNVVE-----LPNFYYASNgTYNCTDAVltysNFGICADGSIIPVRPRNV 133
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  685 RSVASQSIIAYTMSlgaensvaysnnsiaIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLN 764
Cdd:cd22375    134 SDNGVSAIVTANLS---------------IPSNWTTSVQVEYLQITSTPIVVDCSTYVCNGNPRCVELLKQYTSACKTIE 198
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  765 RALTGIAVEQDKNTQEVFAQVKQIYKTPPIKDFGGFNFSQILP----DPSKPSKRSFIEDLLFNKVTLADAGFIK-QYGD 839
Cdd:cd22375    199 DALRLSARLESADVSSMLTFDSNAFTLANVSSFGDYNLSSVLPqlptSGSRIAGRSAIEDLLFSKVVTSGLGTVDaDYKS 278
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  840 CLGDIAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTfgagAALQIPFAMQMAYRFNGIGVTQNVLYEN 919
Cdd:cd22375    279 CTKGLSIADLACAQYYNGIMVLPGVADAERMAMYTGSLIGGMALGGLT----SAAAIPFSLALQARLNYVALQTDVLQEN 354
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  920 QKLIANQFNSAIGKIQDSLSST--------------ASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLD 985
Cdd:cd22375    355 QKILAASFNKAMTNIVDAFTGVndaitqtsqaiqtvATALNKIQDVVNQQGNALNHLTSQLRQNFQAISSSIQAIYDRLD 434
                          490       500       510       520       530       540       550       560
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  986 KVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHV 1065
Cdd:cd22375    435 TIQADQQVDRLITGRLAALNAFVSQTLTKYTEVRASRQLAQQKVNECVKSQSNRYGFCGNGTHIFSIVNAAPEGLVFLHT 514
                          570       580       590       600       610       620       630       640
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1066 TYVPAQEKNFTTAPAICHDGKAHFPREG---VFVSNGTHWFVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQ 1142
Cdd:cd22375    515 VLLPTQYKDVEAWSGLCVDGVNGYVLRQpnlALYKDGGVFRITSRVMFEPRIPTMADFVQIENCNVTFVNISRSELQTIV 594
                          650       660       670       680       690       700       710       720
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598 1143 PE-LDSFK--EELDKYFKNHTSPDVDL-----------GDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQ 1208
Cdd:cd22375    595 PEyVDVNKtlQELIEKLPNYTVPDLDLdqynqtilnltSEISTLENKSAELNYTVQKLQTLIDNINSTLVDLKWLNRVET 674

                   ...
gi 1796318598 1209 YIK 1211
Cdd:cd22375    675 YIK 677
CoV_Spike_S1_RBD cd21470
receptor-binding domain of the S1 subunit of coronavirus spike (S) proteins; This family ...
320-526 2.18e-72

receptor-binding domain of the S1 subunit of coronavirus spike (S) proteins; This family contains the receptor-binding domain (RBD) of the S1 subunit of coronavirus (CoV) spike (S) proteins from three highly pathogenic human coronaviruses (CoVs), including Middle East respiratory syndrome coronavirus (MERS-CoV), Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS coronavirus 2 (SARS-CoV-2), also known as a 2019 novel coronavirus (2019-nCoV), as well as S proteins from related coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. MHV uses mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a) as the receptor, and the receptors for SARS-CoV and MERS-CoV are human angiotensin-converting enzyme 2 (ACE2) and human dipeptidyl peptidase 4 (DPP4), respectively. Recent studies found that the RBD of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394823  Cd Length: 171  Bit Score: 238.53  E-value: 2.18e-72
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  320 VQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADS 399
Cdd:cd21470      1 VKPSGSVVRRPNNTPLCDFSEWLNATSVPSVYNWERKVFSNCNFNLSKLLSLFSVDSFTCNGISPAKIAGLCFSSITVDK 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  400 FVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFrksnlkpferdisteiyqagstp 479
Cdd:cd21470     81 FAIPLSRKSDLQPGSAGFIQDYNYKIDFDNTSCQLAYNLPANNATITKNHDYVYIQK----------------------- 137
                          170       180       190       200
                   ....*....|....*....|....*....|....*....|....*..
gi 1796318598  480 cngvegfncYFPLQSYGFQPtngvGYQPYRVVVLSFELLHAPATVCG 526
Cdd:cd21470    138 ---------FLGWSTDGCTS----GDQCQIFFNISFQYGNASGTVCS 171
bCoV_S1_N pfam16451
Betacoronavirus-like spike glycoprotein S1, N-terminal; This entry represents the N-terminal ...
34-334 8.49e-65

Betacoronavirus-like spike glycoprotein S1, N-terminal; This entry represents the N-terminal domain of the betacoronavirus-like trimeric spike glycoprotein. The distal S1 subunit of the coronavirus spike protein is responsible for receptor binding. S1 contains two domains; an N-terminal galectin-like domain (NTD) and a receptor-binding domain (S1 RBD) also referred to as the S1 CTD or domain B. Either the S1 NTD or S1 RBD, or occasionally both, are involved in binding to host receptors. S1 NTD is located on the side of the spike trimer and mainly recognizes sugar receptors. For many betacoronaviruses (b-CoVs), for example mouse hepatitis virus (MHV), the RBD is located in the NTD. The structure of the MHV S1 NTD showed the same fold as human galectins (galactose-binding lectin), however it does not bind any sugar; instead, it binds to the carcinoembryonic antigen cell-adhesion molecule CEACAM1) through protein-protein interactions. All three CEACAM21a-binding sites in MHV spikes can be fully occupied by CEACAM1a. It has been shown that CEACAM1a binding to the MHV spike weakens the interactions between S1 and S2 and facilitates the proteolysis of the spike protein and dissociation of S1. The homologous bovine CoV (BCov) S1 NTD also possesses a galectin fold but binds to sialic acid-containing moieties on host cell membranes, as does the NTD of three other group A b-Covs, namely human CoV (HCoV) OC43, avian b-CoV, and infectious bronchitis virus (IBV). Despite the S1 NTD of human respiratory b-CoV HKU1 being highly homologous to the NTDs of MHV and bovine CoV, it does not bind to either sugar or human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) and the RBD is found instead in the S1 RBD domain.


Pssm-ID: 465119  Cd Length: 296  Bit Score: 221.90  E-value: 8.49e-65
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   34 RGVYY-PDKVFrSSVLHSTQDLFLPFFSNVTWFhAIHVSGTNGTKRFDNPVLPFNDGVYFASTEKSNIIRG--------W 104
Cdd:pfam16451    6 DGTYYlPDRVY-SNTTTLRQGLFPKQGDNVTNY-VYSPAHHCGKRNFSTPFLPFGDGIFVHIGNASNATGGriiseppaF 83
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  105 IFGTTLDSKTQSLLIVNNA--TNVVIKVCEFQFCNDPFLGVyyhknnkSWMESEFRVYSS------ANNCTFEYVSqPFL 176
Cdd:pfam16451   84 VFGSTFGNTSHTLIIAPDScqTNLTILVCNFTLCANPVTAC-------RWGAGNYNANNSlvyfknAINCTFNRTY-NIT 155
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  177 MDlegkqgnfKNLREFVFKNIDGYFKIYSKHTPInlvrDLPQGFSALEPLVDLPIGINITRFQTLLalhRSYltpgDSSS 256
Cdd:pfam16451  156 FD--------TSLIYFGFKQQDGGFHIYYSYWLP----DLDSGPPTLFPFATLPLGINITYFQVIP---SSI----RSTQ 216
                          250       260       270       280       290       300       310
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1796318598  257 GWTAGAAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKCTLKSFTVEKGIYQTSNFRVQPTESIV-RFPNITN 334
Cdd:pfam16451  217 NCRRANAAYYVAPLKPSTFLLDFDVNGYITNAVDCSFDPLSELKCSTGSFEPDTGVYSTSSYRAQPVGSVYvRQPNVTC 295
CoV_Spike_S1_NTD cd21527
N-terminal domain of the S1 subunit of coronavirus Spike (S) proteins; This family contains ...
34-301 4.70e-49

N-terminal domain of the S1 subunit of coronavirus Spike (S) proteins; This family contains the N-terminal domain (NTD) of the S1 subunit of coronavirus (CoV) Spike (S) proteins from all four (A-D) lineages of betacoronaviruses, including three highly pathogenic human CoVs (HCoV) such as Middle East respiratory syndrome (MERS)-related CoV, Severe acute respiratory syndrome (SARS) CoV, and SARS-CoV-2, also known as a 2019 novel coronavirus (2019-nCoV) or COVID-19 virus. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV, use the C-domain to bind their receptors. However, some CoVs from the A lineage, such as mouse hepatitis virus (MHV) uses the NTD to bind its receptor, mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a). Bovine CoV and HCoV-OC43, also from the A lineage, recognize a sugar moiety, 5-N-acetyl-9-O-acetylneuraminic acid (Neu5,9Ac2), on cell-surface glycoproteins or glycolipids; this binding is also through the S1 NTD. The S1 NTD has also been the target for neutralizing antibodies, including human antibody CDC2-A2, and murine antibodies G2 and 5F9, which target MERS-CoV NTD. In addition, the S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394949  Cd Length: 268  Bit Score: 175.75  E-value: 4.70e-49
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598   34 RGVYYPDKVFRSSVLHSTQDLFLPFFSNVTWFHAI--HVSGTNGTKrfDNPVLPFNDGVYFASTEK--------SNIIRG 103
Cdd:cd21527     13 LGTYYPDDRVYSNTTLLLQGLFPYDGSNFTNYALKgsHALGTLWFY--PPFVSPFNNGIFVKVKNTknstsatiYSEYPA 90
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  104 WIFGTTLDSKTQSLLIVNN--ATNVVIKVCEFQFCNDPflgVYYH--KNNKSWMESEFRVYSSANNCTFEYVSQPFlmdl 179
Cdd:cd21527     91 IVFGSTFGNTSYTVVIQPDngGTLLEASACQYEMCEYN---ATICvpKTDGSDGNYSWHIDSNAFNCTFEYNFTYN---- 163
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  180 egkqgNFKNLREFVFKNIDGYFKIYSKHTPinlvrdlPQGFSALEPLVDLPIGINITRFQTLLALHRSyltpgdSSSGWT 259
Cdd:cd21527    164 -----VNADLLYFGFYQEDGTLYAYYSDYV-------DLYGGPLKFLFSLPLGDNLTNYYVIPLTCRS------IQSSDR 225
                          250       260       270       280
                   ....*....|....*....|....*....|....*....|..
gi 1796318598  260 AGAAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKC 301
Cdd:cd21527    226 KFAAAYYVTYLTPRTFLLNFDENGVITNAVDCSSNFLSELKC 267
bCoV_S1_RBD pfam09408
Betacoronavirus spike glycoprotein S1, receptor binding; This entry represents the receptor ...
348-502 1.04e-43

Betacoronavirus spike glycoprotein S1, receptor binding; This entry represents the receptor binding domain (S1 RBD) of the betacoronavirus spike glycoprotein. The spike glycoprotein is arranged in trimers on the surface of the viral membrane and is essential for viral entry. The spike protein is translated as a large polypeptide that is subsequently cleaved to the distal S1, responsible for receptor binding, and the membrane-anchored S2 responsible for membrane fusion. The coronavirus (SARS-CoV) S1 subunit is composed of two distinct domains: an N-terminal domain (S1 NTD) and a receptor-binding domain (S1 RBD) also referred to as the S1 CTD or domain B. Each of these domains have been implicated in binding to host receptors. However, most coronaviruses are not known to utilize both the S1 NTD and S1 RBD for viral entry. SARS-CoV makes use of its S1 RBD to bind to the human angiotensin-converting enzyme 2 (ACE2) as its host receptor.


Pssm-ID: 462789  Cd Length: 156  Bit Score: 156.12  E-value: 1.04e-43
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  348 ASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADSFVIRGDEVRQIAPGQTGKIADYNYKLPD 427
Cdd:pfam09408    1 PSPANWERKTFSNCNFDFSVLLSLLQVSSFKCYGVSPSKLADMCYGSVTIDYFAIPETHKSNLQPGSPGAISKYNYKLPD 80
                           90       100       110       120       130       140       150
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1796318598  428 DFTGCVIAWNSNNLDSkVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGSTPCNgvegFNCYFPLQSYGFQPTNG 502
Cdd:pfam09408   81 DFYGCVLAFNVNANTN-YAFADNYPYRYIKPGQYQPCNSFVSTVPNSPDGHYCT----PSSFNGVVVITLKPATG 150
batCoV-HKU9-like_Spike_S1_NTD cd21627
N-terminal domain of the S1 subunit of the Spike (S) protein from Rousettus bat coronavirus ...
192-301 2.46e-08

N-terminal domain of the S1 subunit of the Spike (S) protein from Rousettus bat coronavirus HKU9 and related betacoronaviruses in the D lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the nobecovirus subgenera (D lineage), including Rousettus bat coronavirus HKU9 and related bat CoVs. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2, SARS-CoV, and MERS-CoV use the C-domain to bind their receptors. However, CoV such as mouse hepatitis virus (MHV) uses the NTD to bind its receptor, mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a). The S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394953  Cd Length: 289  Bit Score: 56.97  E-value: 2.46e-08
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  192 FVFKniDGYFKIYskHTPI--NLVRDLPQGFSaLEPLVDLPIGINITRFQTLLALHRSYLTPGDSSSgwTAGAAAYYVGY 269
Cdd:cd21627    184 FRFK--DGNLLLY--HSAWlpTSGLNLSGDYP-LHYYMSVPVGFNLPNAQFFQSVVRPNTEPADGAC--AAFQNNLYIAP 256
                           90       100       110
                   ....*....|....*....|....*....|..
gi 1796318598  270 LQPRTFLLKYNENGTITDAVDCALDPLSETKC 301
Cdd:cd21627    257 LSKRELLVSYDDNGSPVNVADCSADAGSELYC 288
HCoV-OC43-like_Spike_S1_RBD cd21485
receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus OC43 ...
318-437 3.71e-08

receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus OC43 and related proteins; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from several betacoronaviruses including human coronavirus OC43 (HCoV-OC43) and bovine respiratory coronavirus (BCoV), among others. HCoV-OC43 is of zoonotic origin and is endemic in the human population, causing mild respiratory tract infections and possible severe complications or fatalities in young children, the elderly, and immunocompromised individuals. These viruses are related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs use the C-domain to bind their receptors. It has been reported that HCoV-OC43 uses 9-O-acetyl-sialic acid (9-O-Ac-Sia) as a receptor, which is terminally linked to oligosaccharides decorating glycoproteins and gangliosides at the host cell surface. HCoV-OC43 appears to bind 9-O-Ac-Sia at the NTD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394832  Cd Length: 312  Bit Score: 56.55  E-value: 3.71e-08
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  318 FRVQPTESIVR-FPNITNlCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVY 396
Cdd:cd21485      3 YTVQPIADVYRrIPNLPD-CNIEAWLNDKSVPSPLNWERKTFSNCNFNMSSLMSFIQADSFTCNNIDAAKIYGMCFSSIT 81
                           90       100       110       120
                   ....*....|....*....|....*....|....*....|.
gi 1796318598  397 ADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWN 437
Cdd:cd21485     82 IDKFAIPNGRKVDLQLGNLGYLQSFNYRIDTTATSCQLYYN 122
HEV_Spike_S1_RBD cd21508
receptor-binding domain of the S1 subunit of the Spike (S) protein from porcine ...
316-437 1.14e-07

receptor-binding domain of the S1 subunit of the Spike (S) protein from porcine hemagglutinating encephalomyelitis virus; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from porcine hemagglutinating encephalomyelitis virus (HEV), which is associated with acute outbreaks of wasting and encephalitis in nursing piglets from pig farms. Porcine HEV is related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs use the C-domain to bind their receptors. The protein receptor for porcine HEV has not yet been identified. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394835  Cd Length: 298  Bit Score: 55.13  E-value: 1.14e-07
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  316 SNFRVQPTESIVR-FPNITNlCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTN 394
Cdd:cd21508      1 NGYTVQPVATVYRrIPDLPN-CDIEAWLNSKTVSSPLNWERKIFSNCNFNMGRLMSFIQADSFGCNNIDASRLYGMCFGS 79
                           90       100       110       120
                   ....*....|....*....|....*....|....*....|...
gi 1796318598  395 VYADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWN 437
Cdd:cd21508     80 ITIDKFAIPNSRKVDLQVGKSGYLQSFNYKIDTAVSSCQLYYS 122
HKU1-like_CoV_Spike_S1_RBD cd21478
receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1 ...
316-432 2.64e-07

receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1 and related coronaviruses; This family contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from human coronavirus (CoV) HKU1, human coronavirus OC43 (HCoV-OC43), mouse hepatitis virus (MHV), porcine hemagglutinating encephalomyelitis virus (HEV), and other related coronaviruses. HKU1 is a human betacoronavirus that causes mild yet prevalent respiratory disease. HCoV-OC43 is of zoonotic origin and is endemic in the human population, causing mild respiratory tract infections and possible severe complications or fatalities in young children, the elderly, and immunocompromised individuals. MHV is the most common viral pathogen in contemporary laboratory mouse colonies manifesting as a primary infection in the upper respiratory tract. Porcine HEV is associated with acute outbreaks of wasting and encephalitis in nursing piglets from pig farms. These viruses are related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBDs of MHV and HCoV-OC43 are located at the NTD, most CoVs use the C-domain to bind their receptors. Although a protein receptor has not yet been identified for HKU1, antibodies against the C-domain, but not those against the NTD, blocked HKU1 infection of cells, suggesting that the S1 C-domain is the primary HKU1 receptor-binding site. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394825  Cd Length: 223  Bit Score: 52.85  E-value: 2.64e-07
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  316 SNFRVQPTESIVR-FPNITNlCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTN 394
Cdd:cd21478      1 TGYTVQPIADVYRrIPNLPD-CDIEEWLNAPTVPSPLNWERKTFSNCNFNMSSLLSLVQADSFSCNNIDASKIYGMCFGS 79
                           90       100       110
                   ....*....|....*....|....*....|....*...
gi 1796318598  395 VYADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGC 432
Cdd:cd21478     80 ITIDKFAIPNSRKVDLQLGSSGYLQSFNYRIDTAATSC 117
bat_HKU4-like_Spike_S1_RBD cd21487
receptor-binding domain of the S1 subunit of the Spike (S) protein from Tylonycteris bat ...
320-473 1.82e-06

receptor-binding domain of the S1 subunit of the Spike (S) protein from Tylonycteris bat coronavirus HKU4 and similar proteins; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from Tylonycteris bat coronavirus HKU4 and other Middle East Respiratory Syndrome (MERS)-related coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including human MERS-CoV that is phylogenetically closely related to bat CoV HKU4 use the C-domain to bind their receptors. HKU4 is able to bind the MERS-CoV receptor, human dipeptidyl peptidase 4 (DPP4), also called CD26. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs including MERS-CoV, and most likely, bat CoV HKU4.


Pssm-ID: 394834  Cd Length: 219  Bit Score: 50.36  E-value: 1.82e-06
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  320 VQPTESIVRFPNITNlCPFGEVFNATRfASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADS 399
Cdd:cd21487      1 ASATGTFIEQPNATE-CDFSPMLTGVA-PQVYNFKRLVFSNCNYNLTKLLSLFAVDEFSCNGISPDAIARGCYSTLTVDY 78
                           90       100       110       120       130       140       150
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1796318598  400 FVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGC-VIAWNSNNLDSKVGGNYNYLYRLfrkSNLKPFERDISTEIY 473
Cdd:cd21487     79 FAYPLSMKSYIRPGSAGNIPLYNYKQSFANPTCrVMASVPANVTITKPEAYGYISKC---SRLTGDNQHIETPLY 150
MHV-like_Spike_S1_NTD cd21625
N-terminal domain of the S1 subunit of the Spike (S) protein from murine hepatitis virus and ...
265-301 2.81e-06

N-terminal domain of the S1 subunit of the Spike (S) protein from murine hepatitis virus and related betacoronaviruses in the A lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the embecovirus subgenera (A lineage), including murine hepatitis virus (MHV), human coronavirus (HCoV) HKU1 and OC43, and bovine CoV (BCoV). MHV is the most common viral pathogen in contemporary laboratory mouse colonies manifesting as a primary infection in the upper respiratory tract, while HCoV-HKU1 causes mild yet prevalent respiratory disease in humans. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While most CoVs, including SARS-CoV and MERS-CoV use the C-domain to bind their receptors, several CoVs in the A lineage use the NTD to bind their receptors. MHV binds its protein receptor, mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a), through its S1 NTD. BCoV and HCoV-OC43 recognize a sugar moiety, 5-N-acetyl-9-O-acetylneuraminic acid (Neu5,9Ac2), on cell-surface glycoproteins or glycolipids; this binding is also through the S1 NTD. In addition, the S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394951  Cd Length: 284  Bit Score: 50.47  E-value: 2.81e-06
                           10        20        30
                   ....*....|....*....|....*....|....*..
gi 1796318598  265 YYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKC 301
Cdd:cd21625    246 YWVTPLTKRQYLLAFNQDGVITNAVDCASDFMSEIKC 282
HKU1_N1_CoV_Spike_S1_RBD cd21483
receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1, ...
316-450 4.31e-06

receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1, isolate N1; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from human coronavirus (CoV) HKU1, isolate N1. HKU1 is a human betacoronavirus that causes mild yet prevalent respiratory disease, and is related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs use the C-domain to bind their receptors. Although a protein receptor has not yet been identified for HKU1, antibodies against the C-domain, but not those against the NTD, blocked HKU1 infection of cells, suggesting that the S1 C-domain is the primary HKU1 receptor-binding site. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs, and most likely, for HKU1.


Pssm-ID: 394830  Cd Length: 306  Bit Score: 50.11  E-value: 4.31e-06
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  316 SNFRVQPTESI-VRFPNITNlCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTN 394
Cdd:cd21483      1 SGFTVKPVATVhRRIPDLPD-CDIDKWLNNFNVPSPLNWERKIFSNCNFNLSTLLRLVHTDSFSCNNFDESKIYGSCFKS 79
                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|....*.
gi 1796318598  395 VYADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVgGNYN 450
Cdd:cd21483     80 IVLDKFAIPNSRRSDLQLGSSGFLQSSNYKIDTTSSSCQLYYSLPAINVTI-NNYN 134
MHV-like_Spike_S1_RBD cd21484
receptor-binding domain of the S1 subunit of the Spike (S) protein from mouse hepatitis virus ...
316-432 6.48e-06

receptor-binding domain of the S1 subunit of the Spike (S) protein from mouse hepatitis virus and other rodent coronaviruses; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from mouse hepatitis virus (MHV) and other rodent coronaviruses. MHV is the most common viral pathogen in contemporary laboratory mouse colonies manifesting as a primary infection in the upper respiratory tract. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). MHV uses mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a) as the receptor; the RBD of MHV is located at the NTD. Most CoVs, such as SARS-CoV and MERS-CoV, use the C-domain to bind their receptors. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394831  Cd Length: 264  Bit Score: 49.11  E-value: 6.48e-06
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  316 SNFRVQPTESIVRfpNITNL--CPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFT 393
Cdd:cd21484      1 SGYTVQPVGVVYR--RVPNLpdCKIEEWLTAKSVPSPLNWERKTFQNCNFNLSSLLRYVQAESLSCNNIDASKVYGMCFG 78
                           90       100       110
                   ....*....|....*....|....*....|....*....
gi 1796318598  394 NVYADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGC 432
Cdd:cd21484     79 SISIDKFAIPNSRRVDLQLGNSGFLQSFNYKIDTRATSC 117
HKU1_N5-like_CoV_Spike_S1_RBD cd21482
receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1, ...
316-450 1.09e-05

receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1, isolate N5 and isolate N2; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from human coronavirus (CoV) HKU1, isolates N5 and N2. HKU1 is a human betacoronavirus that causes mild yet prevalent respiratory disease, and is related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs use the C-domain to bind their receptors. Although a protein receptor has not yet been identified for HKU1, antibodies against the C-domain, but not those against the NTD, blocked HKU1 infection of cells, suggesting that the S1 C-domain is the primary HKU1 receptor-binding site. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs, and most likely, for HKU1.


Pssm-ID: 394829  Cd Length: 304  Bit Score: 48.91  E-value: 1.09e-05
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  316 SNFRVQPTESIVR-FPNITNlCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTN 394
Cdd:cd21482      1 SGFTVKPVATVYRrIPNLPD-CDIDNWLNNVSVPSPLNWERRIFSNCNFNLSTLLRLVHVDSFSCNNLDKSKIFGSCFNS 79
                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|....*.
gi 1796318598  395 VYADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVgGNYN 450
Cdd:cd21482     80 ITVDKFAIPNRRRDDLQLGSSGFLQSSNYKIDISSSSCQLYYSLPLLNVTI-NNFN 134
MERS-CoV-like_Spike_S1_NTD cd21626
N-terminal domain of the S1 subunit of the Spike (S) protein from Middle East respiratory ...
246-302 1.86e-05

N-terminal domain of the S1 subunit of the Spike (S) protein from Middle East respiratory syndrome-related coronavirus and related betacoronaviruses in the C lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the merbecovirus subgenera (C lineage), including the highly pathogenic human coronavirus (CoV), Middle East respiratory syndrome (MERS)-related CoV, and related bat CoVs. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including MERS-CoV, use the C-domain to bind their receptors. Despite using the C-domain as its receptor, neutralizing antibodies targeting MERS-CoV S1-NTD have been reported, including human antibody CDC2-A2, murine antibodies G2 and 5F9, and macaque antibodies FIB-H1 and JC57-13. G2 has been shown to strongly disrupt the attachment of MERS-CoV S to its receptor, dipeptidyl peptidase-4 (DPP4). In addition, the S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394952  Cd Length: 328  Bit Score: 48.50  E-value: 1.86e-05
                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*..
gi 1796318598  246 RSYLTPGDSSSGWtagaAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKCT 302
Cdd:cd21626    276 RSIRSPQNDRKAW----AAFYIYKLHPLTYLLDFDVDGYIRRAIDCGYDDLSQLQCS 328
MERS-like_CoV_Spike_S1_RBD cd21479
receptor-binding domain of the S1 subunit of the Spike (S) protein from Middle East ...
320-499 4.13e-05

receptor-binding domain of the S1 subunit of the Spike (S) protein from Middle East respiratory syndrome coronavirus; This family contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from the human coronavirus that causes Middle East Respiratory Syndrome (MERS-CoV) and related coronaviruses from animals. MERS-CoV causes severe pulmonary disease in humans. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including MERS-CoV use the C-domain to bind their receptors. MERS-CoV use human dipeptidyl peptidase 4 (DPP4), also called CD26, as its receptor. It binds DPP4 through the RBD of its S1 subunit and then fuses viral and host membranes through its S2 subunit. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs including MERS-CoV.


Pssm-ID: 394826  Cd Length: 216  Bit Score: 46.23  E-value: 4.13e-05
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  320 VQPTESIVRFPNITNlCPFGEVFNATRfASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADS 399
Cdd:cd21479      1 AKPRGTFIEQAEGVE-CDFSPLLKGTP-PQVYNFKRLVFTNCNYNLTKLLSLFQVDEFSCHQISPSALATGCYSSLTVDY 78
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1796318598  400 FVIRGDEVRQIAPGQTGKIADYNYKlpDDFTG--CVI--AWNSNNLDSKVgGNYNYLYRLFRKSNlkpferDISTEIY-Q 474
Cdd:cd21479     79 FAYPLSMKSYLQPGSAGPIVQFNYK--QDFSNptCRIlaTVPANLTITKP-SNYSYITKCSRLTG------DGKNPQYvN 149
                          170       180       190
                   ....*....|....*....|....*....|.
gi 1796318598  475 AGS-TPC-----NGVEGFNCYFPLQSYGFQP 499
Cdd:cd21479    150 PGQyTPClcfspSGLAEDGFYFSYQLHGLEG 180
CoV_S1_C pfam19209
Coronavirus spike glycoprotein S1, C-terminal; This entry represents a domain found at the ...
536-592 7.86e-04

Coronavirus spike glycoprotein S1, C-terminal; This entry represents a domain found at the C-terminus of the Coronavirus S1 protein. It is found across a range of alpha, beta and gamma coronaviruses. This small all beta stranded domain is known as subdomain 2 in the structure of the porcine epidemic diarrhea virus spike protein.


Pssm-ID: 437047 [Multi-domain]  Cd Length: 57  Bit Score: 38.76  E-value: 7.86e-04
                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*..
gi 1796318598  536 NKCVNFNFNGLTGTGVLTESNKKFLPfQQFGRDIADTTDAVRDPQTLEILDITPCSF 592
Cdd:pfam19209    1 NVCTDYTIYGITGTGVIRETNSTIPS-GLYYTSSSGDLLGFKNSTTGTVYSVTPCVS 56
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
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