Annotations: 7RXD

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
E [auth R]	SCOP2B Superfamily	SARS coronavirus receptor-binding domain-like	8092467	3001706	SCOP2B (2022-06-29)
A [auth B]	SCOP2B Superfamily	Bacterial immunoglobulin/albumin-binding domains	8105461	3001373	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
E [auth R]	Spike_rec_bind	e7rxdR1	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: Spike_rec_bind	ECOD (1.6)
D [auth N]	V-set_8	e7rxdN1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
C [auth L]	C1-set_4	e7rxdL2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_4	ECOD (1.6)
C [auth L]	V-set	e7rxdL1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set	ECOD (1.6)
B [auth H]	V-set_8	e7rxdH1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
B [auth H]	C1-set_1	e7rxdH2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: C1-set_1	ECOD (1.6)
A [auth B]	B,IgG_binding_B	e7rxdB3	A: alpha arrays	X: DnaD domain (From Topology)	H: DnaD domain (From Topology)	T: DnaD domain	F: B,IgG_binding_B	ECOD (1.6)
A [auth B]	SBP_bac_1_C	e7rxdB2	A: a/b three-layered sandwiches	X: Periplasmic binding protein-like II (From Topology)	H: Periplasmic binding protein-like II (From Topology)	T: Periplasmic binding protein-like II	F: SBP_bac_1_C	ECOD (1.6)
A [auth B]	SBP_bac_1_N_1	e7rxdB1	A: a/b three-layered sandwiches	X: Periplasmic binding protein-like II (From Topology)	H: Periplasmic binding protein-like II (From Topology)	T: Periplasmic binding protein-like II	F: SBP_bac_1_N_1	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
D [auth N]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
C [auth L]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
B [auth H]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
A [auth B]	3.40.190.10	Alpha Beta	3-Layer(aba) Sandwich	D-Maltodextrin-Binding Protein	domain 2	CATH (utative)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
D [auth N]	Heavy Chain	IGHV1	-	spike protein s1	SAbDab (2025-12-19)
C [auth L]	Light Chain	IGKV8	Kappa	maltodextrin-binding protein,immunoglobulin g-bindingprotein a,immunoglobulin g-binding protein g	SAbDab (2025-12-19)
B [auth H]	Heavy Chain	IGHV5	-	maltodextrin-binding protein,immunoglobulin g-bindingprotein a,immunoglobulin g-binding protein g	SAbDab (2025-12-19)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
E [auth R]	PF09408	Betacoronavirus spike glycoprotein S1, receptor binding (bCoV_S1_RBD)	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 translat ...	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
A [auth B]	PF02216	B domain (B)	B domain	This family contains the B domain of Staphylococcal protein A, which specifically binds to the Fc portion of immunoglobulin G.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
E [auth R]	Spike protein S1	protein binding binding molecular function activator activity signaling receptor binding molecular function regulator activity signaling receptor regulator activity receptor ligand activity signaling receptor activator activity host cell surface binding host cell surface receptor binding structural constituent of virion structural molecule activity identical protein binding	viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell membrane organization cellular component organization membrane fusion cellular process cellular component organization or biogenesis symbiont-mediated disruption of host anatomical structure biological process involved in interspecies interaction between organisms symbiont-mediated disruption of host tissue disruption of anatomical structure in another organism symbiont entry into host cell symbiont entry into host viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell membrane organization cellular component organization membrane fusion cellular process cellular component organization or biogenesis symbiont-mediated disruption of host anatomical structure biological process involved in interspecies interaction between organisms symbiont-mediated disruption of host tissue disruption of anatomical structure in another organism symbiont entry into host cell symbiont entry into host viral life cycle biological process involved in interaction with host biological process involved in symbiotic interaction virion attachment to host cell receptor-mediated virion attachment to host cell adhesion of symbiont to host cell adhesion of symbiont to host viral gene expression viral translation fusion of virus membrane with host plasma membrane endocytosis involved in viral entry into host cell symbiont-mediated perturbation of host defense response symbiont-mediated perturbation of host process symbiont-mediated-mediated suppression of host tetherin activity modulation of process of another organism regulation of biological process positive regulation of viral life cycle positive regulation of viral process biological regulation positive regulation of biological process modulation by symbiont of entry into host regulation of viral entry into host cell regulation of viral life cycle regulation of viral process positive regulation of viral entry into host cell positive regulation by symbiont of entry into host regulation of biological process involved in symbiotic interaction symbiont-mediated suppression of host immune response symbiont-mediated suppression of host innate immune response symbiont-mediated perturbation of host immune response symbiont-mediated perturbation of host innate immune response entry receptor-mediated virion attachment to host cell	cellular anatomical structure membrane host extracellular space host cellular component other organism part cell periphery plasma membrane host intracellular membrane-bounded organelle host intracellular part host cell membrane host cell cytoplasm part host intracellular organelle host cell endoplasmic reticulum-Golgi intermediate compartment membrane host cell endoplasmic reticulum-Golgi intermediate compartment cellular anatomical structure membrane host extracellular space host cellular component other organism part cell periphery plasma membrane host intracellular membrane-bounded organelle host intracellular part host cell membrane host cell cytoplasm part host intracellular organelle host cell endoplasmic reticulum-Golgi intermediate compartment membrane host cell endoplasmic reticulum-Golgi intermediate compartment host cell cytoplasm host cell part host intracellular region host cell plasma membrane virion component virion membrane viral membrane viral envelope host cell surface
D [auth N]	Nb_RBD	-	-	-
C [auth L]	Fab_8D3_2 light chain	-	-	-
B [auth H]	Fab_8D3_2 heavy chain	-	-	-
A [auth B]	Maltodextrin-binding protein,Immunoglobulin G-binding protein A,Immunoglobulin G-binding protein G	protein-containing complex binding binding immunoglobulin binding IgG binding	-	cellular anatomical structure extracellular region

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
E [auth R]	IPR044873	Spike glycoprotein S2, coronavirus, heptad repeat 1	Domain
E [auth R]	IPR044366	Spike (S) protein S1 subunit, receptor-binding domain, SARS-CoV-2	Domain
E [auth R]	IPR018548	Spike (S) protein S1 subunit, receptor-binding domain, betacoronavirus	Domain
E [auth R]	IPR044341	Spike (S) protein S1 subunit, N-terminal domain, SARS-CoV-like	Domain
E [auth R]	IPR032500	Spike glycoprotein S1, N-terminal domain, betacoronavirus-like	Domain
E [auth R]	IPR042578	Spike glycoprotein, betacoronavirus	Family
E [auth R]	IPR036326	Spike S1 subunit, receptor binding domain superfamily, betacoronavirus	Homologous Superfamily
E [auth R]	IPR043002	Spike glycoprotein, N-terminal domain superfamily	Homologous Superfamily
E [auth R]	IPR044874	Spike glycoprotein S2, coronavirus, heptad repeat 2	Domain
E [auth R]	IPR043473	Spike glycoprotein S2 superfamily, coronavirus	Homologous Superfamily
E [auth R]	IPR043607	Coronavirus spike glycoprotein S1, C-terminal	Domain
E [auth R]	IPR002552	Spike glycoprotein S2, coronavirus	Domain
A [auth B]	IPR009063	Immunoglobulin/albumin-binding domain superfamily	Homologous Superfamily
A [auth B]	IPR019950	M protein-type anchor domain	Domain
A [auth B]	IPR005877	YSIRK Gram-positive signal peptide	Domain
A [auth B]	IPR000724	IgG-binding B	Domain
A [auth B]	IPR035152	GA-like domain	Domain
A [auth B]	IPR019931	LPXTG cell wall anchor domain	Domain
A [auth B]	IPR009063	Immunoglobulin/albumin-binding domain superfamily	Homologous Superfamily
A [auth B]	IPR005877	YSIRK Gram-positive signal peptide	Domain
A [auth B]	IPR036779	LysM domain superfamily	Homologous Superfamily
A [auth B]	IPR005038	Octapeptide repeat	Repeat
A [auth B]	IPR003132	Protein A, Ig-binding domain	Domain
A [auth B]	IPR018392	LysM domain	Domain
A [auth B]	IPR019931	LPXTG cell wall anchor domain	Domain