Annotations: 9BU8

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
J	SCOP2B Superfamily	Influenza hemagglutinin domain-like	8087840	3001342	SCOP2B (2022-06-29)
E	SCOP2B Superfamily	Influenza hemagglutinin domain-like	8087840	3001342	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Influenza hemagglutinin domain-like	8087840	3001342	SCOP2B (2022-06-29)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
D, H, K	Light Chain	IGKV3	Kappa	hemagglutinin ha2 \| hemagglutinin ha1	SAbDab (2025-12-19)
C, F, I	Heavy Chain	IGHV3	-	hemagglutinin ha2 \| hemagglutinin ha1	SAbDab (2025-12-19)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
B, G, L	PF00509	Haemagglutinin (Hemagglutinin)	Haemagglutinin	-	Family
A, E, J	PF00509	Haemagglutinin (Hemagglutinin)	Haemagglutinin	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
D, H, K	Fab c115.131 light chain	-	-	-
C, F, I	Fab c115.131 heavy chain	-	-	-
B, G, L	Hemagglutinin HA2	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 membrane organization cellular component organization membrane fusion fusion of virus membrane with host plasma membrane cellular process cellular component organization or biogenesis virion attachment to host cell biological process involved in interspecies interaction between organisms adhesion of symbiont to host cell viral life cycle adhesion of symbiont to 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 fusion of virus membrane with host plasma membrane cellular process cellular component organization or biogenesis virion attachment to host cell biological process involved in interspecies interaction between organisms 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 non-lytic viral release viral budding virion assembly exit from host cell viral budding from plasma membrane viral release from host cell import into cell receptor-mediated endocytosis of virus by host cell transport establishment of localization vesicle-mediated transport localization symbiont entry into host cell clathrin-dependent endocytosis symbiont entry into host clathrin-dependent endocytosis of virus by host cell receptor-mediated endocytosis endocytosis endocytosis involved in viral entry into host cell	cellular anatomical structure membrane virion component virion membrane viral membrane viral envelope host cell plasma membrane host cellular component host cell part host cell membrane other organism part
A, E, J	Hemagglutinin HA1	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 membrane organization cellular component organization membrane fusion fusion of virus membrane with host plasma membrane cellular process cellular component organization or biogenesis virion attachment to host cell biological process involved in interspecies interaction between organisms adhesion of symbiont to host cell viral life cycle adhesion of symbiont to 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 fusion of virus membrane with host plasma membrane cellular process cellular component organization or biogenesis virion attachment to host cell biological process involved in interspecies interaction between organisms 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 non-lytic viral release viral budding virion assembly exit from host cell viral budding from plasma membrane viral release from host cell import into cell receptor-mediated endocytosis of virus by host cell transport establishment of localization vesicle-mediated transport localization symbiont entry into host cell clathrin-dependent endocytosis symbiont entry into host clathrin-dependent endocytosis of virus by host cell receptor-mediated endocytosis endocytosis endocytosis involved in viral entry into host cell	cellular anatomical structure membrane virion component virion membrane viral membrane viral envelope host cell plasma membrane host cellular component host cell part host cell membrane other organism part

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
B, G, L	IPR001364	Haemagglutinin, influenzavirus A/B	Family
B, G, L	IPR008980	Viral capsid/haemagglutinin protein	Homologous Superfamily
B, G, L	IPR000149	Haemagglutinin, influenzavirus A	Family
B, G, L	IPR013828	Haemagglutinin, HA1 chain, alpha/beta domain superfamily	Homologous Superfamily
A, E, J	IPR001364	Haemagglutinin, influenzavirus A/B	Family
A, E, J	IPR008980	Viral capsid/haemagglutinin protein	Homologous Superfamily
A, E, J	IPR000149	Haemagglutinin, influenzavirus A	Family
A, E, J	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.