Annotations: 7M51

B6 Fab fragment bound to the OC43 spike stem helix peptide

External Resource: Annotation

Domain Annotation: ECOD Classification
Domain Annotation: CATH
SAbDab Antibody Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
C [auth L]	Aldedh	e7m51L1	A: a/b three-layered sandwiches	X: CNF1/YfiH-like putative cysteine hydrolases	H: Bromodomain	T: Bromodomain	F: Aldedh	ECOD (v294.1)
B [auth H]	Aldedh	e7m51H1	A: a/b three-layered sandwiches	X: CNF1/YfiH-like putative cysteine hydrolases	H: Bromodomain	T: Bromodomain	F: Aldedh	ECOD (v294.1)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
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)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
C [auth L]	Light Chain	IGKV8	Kappa	spike glycoprotein stem helix peptide	SAbDab (2026-04-24)
B [auth H]	Heavy Chain	IGHV1	-	spike glycoprotein stem helix peptide	SAbDab (2026-04-24)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C [auth L]	B6 antigen-binding (Fab) fragment light chain	-	-	-
B [auth H]	B6 antigen-binding (Fab) fragment heavy chain	-	-	-
A	Spike glycoprotein stem helix peptide	binding carbohydrate binding host cell surface binding host cell surface receptor binding	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 symbiont entry into host cell symbiont entry into host endocytosis involved in viral entry into host cell	cellular anatomical structure membrane virion component virion membrane host intracellular membrane-bounded organelle host cellular component host intracellular part host cell membrane other organism part 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 cellular anatomical structure membrane virion component virion membrane host intracellular membrane-bounded organelle host cellular component host intracellular part host cell membrane other organism part 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 viral membrane viral envelope host cell plasma membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR018548	Spike (S) protein S1 subunit, receptor-binding domain, betacoronavirus	Domain
A	IPR032500	Spike glycoprotein S1, N-terminal domain, betacoronavirus-like	Domain
A	IPR042578	Spike glycoprotein, betacoronavirus	Family
A	IPR036326	Spike S1 subunit, receptor binding domain superfamily, betacoronavirus	Homologous Superfamily
A	IPR043002	Spike glycoprotein, N-terminal domain superfamily	Homologous Superfamily
A	IPR044372	Spike (S) protein S1 subunit, receptor-binding domain, HCoV-OC43-like	Domain
A	IPR044339	Spike (S) protein S1 subunit, N-terminal domain, murine hepatitis virus-like	Domain
A	IPR044874	Spike glycoprotein S2, coronavirus, heptad repeat 2	Domain
A	IPR044873	Spike glycoprotein S2, coronavirus, heptad repeat 1	Domain
A	IPR043473	Spike glycoprotein S2 superfamily, coronavirus	Homologous Superfamily
A	IPR043607	Coronavirus spike glycoprotein S1, C-terminal	Domain
A	IPR002552	Spike glycoprotein S2, coronavirus	Domain

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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. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.