Annotations: 6M39

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	EUF07639	e6m39A3	A: beta sandwiches	X: jelly-roll	H: Concanavalin A-like	T: Concanavalin A-like lectins/glucanases	F: EUF07639	ECOD (1.6)
A	Corona_S1_3rd	e6m39A2	A: beta complex topology	X: Beta domain of coronavirus spike glycoprotein (From Topology)	H: Beta domain of coronavirus spike glycoprotein (From Topology)	T: Beta domain of coronavirus spike glycoprotein	F: Corona_S1_3rd	ECOD (1.6)
A	F_UNCLASSIFIED	e6m39A4	A: a+b three layers	X: Coronavirus spike protein receptor-binding domain (From Homology)	H: Coronavirus spike protein receptor-binding domain	T: Beta-coronavirus spike protein receptor-binding domain	F: F_UNCLASSIFIED	ECOD (1.6)
A	Corona_S2	e6m39A1	A: a+b complex topology	X: S2 subunit of coronavirus spike glycoprotein (From Topology)	H: S2 subunit of coronavirus spike glycoprotein (From Topology)	T: S2 subunit of coronavirus spike glycoprotein	F: Corona_S2	ECOD (1.6)
B	EUF07639	e6m39B3	A: beta sandwiches	X: jelly-roll	H: Concanavalin A-like	T: Concanavalin A-like lectins/glucanases	F: EUF07639	ECOD (1.6)
B	Corona_S1_3rd	e6m39B2	A: beta complex topology	X: Beta domain of coronavirus spike glycoprotein (From Topology)	H: Beta domain of coronavirus spike glycoprotein (From Topology)	T: Beta domain of coronavirus spike glycoprotein	F: Corona_S1_3rd	ECOD (1.6)
B	F_UNCLASSIFIED	e6m39B4	A: a+b three layers	X: Coronavirus spike protein receptor-binding domain (From Homology)	H: Coronavirus spike protein receptor-binding domain	T: Beta-coronavirus spike protein receptor-binding domain	F: F_UNCLASSIFIED	ECOD (1.6)
B	Corona_S2	e6m39B1	A: a+b complex topology	X: S2 subunit of coronavirus spike glycoprotein (From Topology)	H: S2 subunit of coronavirus spike glycoprotein (From Topology)	T: S2 subunit of coronavirus spike glycoprotein	F: Corona_S2	ECOD (1.6)
C	EUF07639	e6m39C3	A: beta sandwiches	X: jelly-roll	H: Concanavalin A-like	T: Concanavalin A-like lectins/glucanases	F: EUF07639	ECOD (1.6)
C	Corona_S1_3rd	e6m39C2	A: beta complex topology	X: Beta domain of coronavirus spike glycoprotein (From Topology)	H: Beta domain of coronavirus spike glycoprotein (From Topology)	T: Beta domain of coronavirus spike glycoprotein	F: Corona_S1_3rd	ECOD (1.6)
C	F_UNCLASSIFIED	e6m39C4	A: a+b three layers	X: Coronavirus spike protein receptor-binding domain (From Homology)	H: Coronavirus spike protein receptor-binding domain	T: Beta-coronavirus spike protein receptor-binding domain	F: F_UNCLASSIFIED	ECOD (1.6)
C	Corona_S2	e6m39C1	A: a+b complex topology	X: S2 subunit of coronavirus spike glycoprotein (From Topology)	H: S2 subunit of coronavirus spike glycoprotein (From Topology)	T: S2 subunit of coronavirus spike glycoprotein	F: Corona_S2	ECOD (1.6)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B, C	PF01601	Coronavirus spike glycoprotein S2 (CoV_S2)	Coronavirus spike glycoprotein S2	-	Family
A, B, C	PF16451	Betacoronavirus-like spike glycoprotein S1, N-terminal (bCoV_S1_N)	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 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
A, B, C	PF19209	Coronavirus spike glycoprotein S1, C-terminal (CoV_S1_C)	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 epide ...	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 [1].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B, C	Spike glycoprotein	-	viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell virion attachment to host cell biological process involved in interspecies interaction between organisms receptor-mediated virion attachment to host cell adhesion of symbiont to host cell viral life cycle adhesion of symbiont to host biological process involved in interaction with host biological process involved in symbiotic interaction membrane organization cellular component organization membrane fusion viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell virion attachment to host cell biological process involved in interspecies interaction between organisms receptor-mediated virion attachment to host cell adhesion of symbiont to host cell viral life cycle adhesion of symbiont to host biological process involved in interaction with host biological process involved in symbiotic interaction membrane organization cellular component organization membrane fusion fusion of virus membrane with host plasma membrane cellular process cellular component organization or biogenesis import into cell transport establishment of localization vesicle-mediated transport localization symbiont entry into host cell symbiont entry into host endocytosis involved in viral entry into host cell endocytosis transport of virus	cellular anatomical structure membrane virion component virion membrane host cellular component host cell part host cell membrane viral membrane viral envelope

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B, C	IPR032500	Spike glycoprotein S1, N-terminal domain, betacoronavirus-like	Domain
A, B, C	IPR044874	Spike glycoprotein S2, coronavirus, heptad repeat 2	Domain
A, B, C	IPR043614	Spike glycoprotein S2, coronavirus, C-terminal	Domain
A, B, C	IPR044873	Spike glycoprotein S2, coronavirus, heptad repeat 1	Domain
A, B, C	IPR043473	Spike glycoprotein S2 superfamily, coronavirus	Homologous Superfamily
A, B, C	IPR043607	Coronavirus spike glycoprotein S1, C-terminal	Domain
A, B, C	IPR002552	Spike glycoprotein S2, coronavirus	Domain

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.