Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

ChainsTypeFamily Name Domain Identifier Family IdentifierProvenance Source (Version)
A [auth D]SCOP2B SuperfamilyImmunoglobulin (Ig) domain-like8003766 3000071 SCOP2B (2022-06-29)
BSCOP2B SuperfamilyImmunoglobulin (Ig) domain-like8003766 3000071 SCOP2B (2022-06-29)
C [auth A]SCOP2B SuperfamilyImmunoglobulin (Ig) domain-like8054615 3000071 SCOP2B (2022-06-29)
C [auth A]SCOP2B SuperfamilyMHC antigen-recognition domain8032356 3000521 SCOP2B (2022-06-29)
D [auth C]SCOP2B SuperfamilyMHC antigen-recognition domain8032356 3000521 SCOP2B (2022-06-29)
D [auth C]SCOP2B SuperfamilyImmunoglobulin (Ig) domain-like8054615 3000071 SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

ChainsFamily NameDomain Identifier ArchitecturePossible HomologyHomologyTopologyFamilyProvenance Source (Version)
A [auth D]C1-set_2e5gsrD1 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: C1-set_2ECOD (1.6)
BC1-set_2e5gsrB1 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: C1-set_2ECOD (1.6)
C [auth A]C1-set_2e5gsrA2 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: C1-set_2ECOD (1.6)
C [auth A]MHC_Ie5gsrA1 A: a+b two layersX: MHC antigen-recognition domain (From Topology)H: MHC antigen-recognition domain (From Topology)T: MHC antigen-recognition domainF: MHC_IECOD (1.6)
D [auth C]C1-set_2e5gsrC2 A: beta sandwichesX: Immunoglobulin-like beta-sandwichH: Immunoglobulin-relatedT: Immunoglobulin/Fibronectin type III/E set domains/PapD-likeF: C1-set_2ECOD (1.6)
D [auth C]MHC_Ie5gsrC1 A: a+b two layersX: MHC antigen-recognition domain (From Topology)H: MHC antigen-recognition domain (From Topology)T: MHC antigen-recognition domainF: MHC_IECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

IMGT Antibody Annotation IMGT Database Homepage

ChainProtein NameDescriptionOrganism NameGene Allele Name(s)Domain Name(s)Receptor TypeReceptor DescriptionProvenance Source
A [auth D],
B
MH1-K1b (H2-K1b) B2M Mus musculus (house mouse) B2M*01, B2M*02 C-LIKE-DOMAIN C-LIKE MH MH1-ALPHA_B2M IMGT (202415-0)
C [auth A],
D [auth C]
MH1-K1b (H2-K1b) I-ALPHA Mus musculus (house mouse) MH1-K1*02 G-DOMAIN G-ALPHA1, G-DOMAIN G-ALPHA2, C-LIKE-DOMAIN C-LIKE MH MH1-ALPHA_B2M IMGT (202415-0)

Protein Family Annotation Pfam Database Homepage

ChainsAccessionNameDescriptionCommentsSource
A [auth D],
B
PF07654Immunoglobulin C1-set domain (C1-set)Immunoglobulin C1-set domain- Domain
C [auth A],
D [auth C]
PF00129Class I Histocompatibility antigen, domains alpha 1 and 2 (MHC_I)Class I Histocompatibility antigen, domains alpha 1 and 2- Domain
C [auth A],
D [auth C]
PF07654Immunoglobulin C1-set domain (C1-set)Immunoglobulin C1-set domain- Domain
E [auth P],
F [auth Q]
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

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

ChainsPolymerMolecular FunctionBiological ProcessCellular Component
A [auth D],
B
Beta-2-microglobulin
C [auth A],
D [auth C]
H-2 class I histocompatibility antigen, K-D alpha chain
E [auth P],
F [auth Q]
9-mer peptide from Spike protein-

InterPro: Protein Family Classification InterPro Database Homepage

ChainsAccessionNameType
A [auth D],
B
IPR036179Immunoglobulin-like domain superfamilyHomologous Superfamily
A [auth D],
B
IPR003006Immunoglobulin/major histocompatibility complex, conserved siteConserved Site
A [auth D],
B
IPR013783Immunoglobulin-like foldHomologous Superfamily
A [auth D],
B
IPR007110Immunoglobulin-like domainDomain
A [auth D],
B
IPR003597Immunoglobulin C1-setDomain
A [auth D],
B
IPR015707Beta-2-MicroglobulinFamily
C [auth A],
D [auth C]
IPR036179Immunoglobulin-like domain superfamilyHomologous Superfamily
C [auth A],
D [auth C]
IPR011162MHC classes I/II-like antigen recognition proteinHomologous Superfamily
C [auth A],
D [auth C]
IPR001039MHC class I alpha chain, alpha1 alpha2 domainsDomain
C [auth A],
D [auth C]
IPR003006Immunoglobulin/major histocompatibility complex, conserved siteConserved Site
C [auth A],
D [auth C]
IPR013783Immunoglobulin-like foldHomologous Superfamily
C [auth A],
D [auth C]
IPR007110Immunoglobulin-like domainDomain
C [auth A],
D [auth C]
IPR003597Immunoglobulin C1-setDomain
C [auth A],
D [auth C]
IPR011161MHC class I-like antigen recognition-likeDomain
C [auth A],
D [auth C]
IPR037055MHC class I-like antigen recognition-like superfamilyHomologous Superfamily
E [auth P],
F [auth Q]
IPR018548Spike (S) protein S1 subunit, receptor-binding domain, betacoronavirusDomain
E [auth P],
F [auth Q]
IPR032500Spike glycoprotein S1, N-terminal domain, betacoronavirus-likeDomain
E [auth P],
F [auth Q]
IPR044376Spike (S) protein S1 subunit, receptor-binding domain, MERS-CoVDomain
E [auth P],
F [auth Q]
IPR042578Spike glycoprotein, betacoronavirusFamily
E [auth P],
F [auth Q]
IPR036326Spike S1 subunit, receptor binding domain superfamily, betacoronavirusHomologous Superfamily
E [auth P],
F [auth Q]
IPR043002Spike glycoprotein, N-terminal domain superfamilyHomologous Superfamily
E [auth P],
F [auth Q]
IPR044874Spike glycoprotein S2, coronavirus, heptad repeat 2Domain
E [auth P],
F [auth Q]
IPR044337Spike (S) protein S1 subunit, N-terminal domain, MERS-CoV-likeDomain
E [auth P],
F [auth Q]
IPR043614Spike glycoprotein S2, coronavirus, C-terminalDomain
E [auth P],
F [auth Q]
IPR044873Spike glycoprotein S2, coronavirus, heptad repeat 1Domain
E [auth P],
F [auth Q]
IPR043473Spike glycoprotein S2 superfamily, coronavirusHomologous Superfamily
E [auth P],
F [auth Q]
IPR043607Coronavirus spike glycoprotein S1, C-terminalDomain
E [auth P],
F [auth Q]
IPR002552Spike glycoprotein S2, coronavirusDomain