Annotations: 9MER

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B [auth H]	Heavy Chain	IGHV4	-	h1h5 ha	SAbDab (2026-01-23)
C [auth L]	Light Chain	IGKV1	Kappa	h1h5 ha	SAbDab (2026-01-23)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A [auth B]	H1H5 HA	host cell surface binding 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 import into cell receptor-mediated endocytosis of virus by host cell biological process involved in interspecies interaction between organisms transport viral life cycle establishment of localization vesicle-mediated transport biological process involved in interaction with host biological process involved in symbiotic interaction localization symbiont entry into host cell viral process fusion of virus membrane with host endosome membrane membrane fusion involved in viral entry into host cell import into cell receptor-mediated endocytosis of virus by host cell biological process involved in interspecies interaction between organisms transport viral life cycle establishment of localization vesicle-mediated transport biological process involved in interaction with host biological process involved in symbiotic interaction localization symbiont entry into host cell clathrin-dependent endocytosis symbiont entry into host cellular process clathrin-dependent endocytosis of virus by host cell receptor-mediated endocytosis endocytosis endocytosis involved in viral entry into host cell membrane organization cellular component organization membrane fusion fusion of virus membrane with host plasma membrane cellular component organization or biogenesis virion attachment to host cell adhesion of symbiont to host cell adhesion of symbiont to host	virion component viral membrane viral envelope cellular anatomical structure membrane host cell plasma membrane host cellular component host cell part host cell membrane other organism part
B [auth H]	FluA20 Heavy Chain Fab	-	-	-
C [auth L]	FluA20 Light Chain Fab	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A [auth B]	IPR001364	Haemagglutinin, influenzavirus A/B	Family
A [auth B]	IPR008980	Viral capsid/haemagglutinin protein	Homologous Superfamily
A [auth B]	IPR000149	Haemagglutinin, influenzavirus A	Family
A [auth B]	IPR013828	Haemagglutinin, HA1 chain, alpha/beta domain superfamily	Homologous Superfamily

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.