Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

ChainsTypeFamily Name Domain Identifier Family IdentifierProvenance Source (Version)
ASCOP2B SuperfamilySARS coronavirus receptor-binding domain-like8092467 3001706 SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

ChainsFamily NameDomain Identifier ArchitecturePossible HomologyHomologyTopologyFamilyProvenance Source (Version)
APF09408e7whzA1 A: a+b three layersX: Coronavirus spike protein receptor-binding domain (From Homology)H: Coronavirus spike protein receptor-binding domainT: Beta-coronavirus spike protein receptor-binding domainF: PF09408ECOD (1.6)
BPF07686e7whzB1 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: PF07686ECOD (1.6)
CPF07686e7whzC1 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: PF07686ECOD (1.6)
DPF07686e7whzD1 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: PF07686ECOD (1.6)
EPF07686e7whzE1 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: PF07686ECOD (1.6)
F [auth H]PF07686e7whzH1 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: PF07686ECOD (1.6)
G [auth L]PF07686e7whzL1 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: PF07686ECOD (1.6)

SAbDab Antibody Annotation SAbDab Database Homepage

ChainChain ClassChain SubclassChain TypeAntigen Name(s) Provenance Source
Heavy ChainIGHV3 -spike protein s1SAbDab (2024-03-22)
Heavy ChainIGHV3 -spike protein s1SAbDab (2024-03-22)
Light ChainIGKV1 Kappaspike protein s1SAbDab (2024-03-22)
Light ChainIGKV1 Kappaspike protein s1SAbDab (2024-03-22)
F [auth H]Heavy ChainIGHV1 -spike protein s1SAbDab (2024-03-22)
G [auth L]Light ChainIGLV1 Lambdaspike protein s1SAbDab (2024-03-22)

Protein Family Annotation Pfam Database Homepage

ChainsAccessionNameDescriptionCommentsSource
PF16451Betacoronavirus-like spike glycoprotein S1, N-terminal (bCoV_S1_N)Betacoronavirus-like spike glycoprotein S1, N-terminalThis 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 doma ...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 recognises sugar receptors [2]. 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 [2]. 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 [2]. 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) [3]. 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 [3].
Domain
PF09408Betacoronavirus spike glycoprotein S1, receptor binding (bCoV_S1_RBD)Betacoronavirus spike glycoprotein S1, receptor bindingThis 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 transla ...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 [1]. 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 utilise both the S1 NTD and S1 RBD for viral entry [2]. SARS-CoV makes use of its S1 RBD to bind to the human angiotensin-converting enzyme 2 (ACE2) as its host receptor [3,4].
Domain
PF07686Immunoglobulin V-set domain (V-set)Immunoglobulin V-set domainThis domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.Domain
PF07686Immunoglobulin V-set domain (V-set)Immunoglobulin V-set domainThis domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.Domain
G [auth L]PF07686Immunoglobulin V-set domain (V-set)Immunoglobulin V-set domainThis domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

ChainsPolymerMolecular FunctionBiological ProcessCellular Component
Spike protein S1
XMA04 heavy chain variable domain---
XMA01 heavy chain variable domain---
IGL c4029_light_IGKV1-39_IGKJ2- - -
IG c934_light_IGKV1-5_IGKJ1- - -
F [auth H]XMA09 heavy chain variable domain---
G [auth L]IG c1437_light_IGLV1-40_IGLJ1- - -

InterPro: Protein Family Classification InterPro Database Homepage

ChainsAccessionNameType
IPR044873Spike glycoprotein S2, coronavirus, heptad repeat 1Domain
IPR044366Spike (S) protein S1 subunit, receptor-binding domain, SARS-CoV-2Domain
IPR018548Spike (S) protein S1 subunit, receptor-binding domain, betacoronavirusDomain
IPR044341Spike (S) protein S1 subunit, N-terminal domain, SARS-CoV-likeDomain
IPR032500Spike glycoprotein S1, N-terminal domain, betacoronavirus-likeDomain
IPR042578Spike glycoprotein, betacoronavirusFamily
IPR036326Spike S1 subunit, receptor binding domain superfamily, betacoronavirusHomologous Superfamily
IPR043002Spike glycoprotein, N-terminal domain superfamilyHomologous Superfamily
IPR044874Spike glycoprotein S2, coronavirus, heptad repeat 2Domain
IPR043473Spike glycoprotein S2 superfamily, coronavirusHomologous Superfamily
IPR043607Coronavirus spike glycoprotein S1, C-terminalDomain
IPR002552Spike glycoprotein S2, coronavirusDomain
IPR013783Immunoglobulin-like foldHomologous Superfamily
IPR036179Immunoglobulin-like domain superfamilyHomologous Superfamily
IPR003599Immunoglobulin subtypeDomain
IPR013106Immunoglobulin V-set domainDomain
IPR007110Immunoglobulin-like domainDomain
IPR013783Immunoglobulin-like foldHomologous Superfamily
IPR036179Immunoglobulin-like domain superfamilyHomologous Superfamily
IPR003599Immunoglobulin subtypeDomain
IPR013106Immunoglobulin V-set domainDomain
IPR007110Immunoglobulin-like domainDomain
G [auth L]IPR013783Immunoglobulin-like foldHomologous Superfamily
G [auth L]IPR036179Immunoglobulin-like domain superfamilyHomologous Superfamily
G [auth L]IPR003599Immunoglobulin subtypeDomain
G [auth L]IPR013106Immunoglobulin V-set domainDomain
G [auth L]IPR007110Immunoglobulin-like domainDomain