Annotations: 7SCO

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
B	SCOP2B Superfamily	Influenza hemagglutinin (stalk)	8105844	3001616	SCOP2B (2022-06-29)
F [auth D]	SCOP2B Superfamily	Influenza hemagglutinin (stalk)	8105844	3001616	SCOP2B (2022-06-29)
J [auth I]	SCOP2B Superfamily	Influenza hemagglutinin (stalk)	8105844	3001616	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)
A	ABC_membrane	e7scoA1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
E [auth C]	ABC_membrane	e7scoC1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
I [auth G]	ABC_membrane	e7scoG1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
B	ABC_membrane	e7scoB1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
F [auth D]	ABC_membrane	e7scoD1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
J [auth I]	ABC_membrane	e7scoI1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
C [auth H]	ABC_membrane	e7scoH1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
G [auth E]	ABC_membrane	e7scoE1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
K [auth J]	ABC_membrane	e7scoJ1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
D [auth L]	ABC_membrane	e7scoL1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
H [auth F]	ABC_membrane	e7scoF1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)
L [auth K]	ABC_membrane	e7scoK1	A: a/b three-layered sandwiches	X: RNase A-like	H: Cytochrome P450	T: Cytochrome P450	F: ABC_membrane	ECOD (v294.1)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B	3.90.20.10	Alpha Beta	Alpha-Beta Complex	Hemagglutinin Ectodomain	Chain B	CATH (utative)
F [auth D]	3.90.20.10	Alpha Beta	Alpha-Beta Complex	Hemagglutinin Ectodomain	Chain B	CATH (utative)
J [auth I]	3.90.20.10	Alpha Beta	Alpha-Beta Complex	Hemagglutinin Ectodomain	Chain B	CATH (utative)
C [auth H]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
G [auth E]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
K [auth J]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
D [auth L]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
H [auth F]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
L [auth K]	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 H], G [auth E], K [auth J]	Heavy Chain	IGHV1	-	hemagglutinin ha2 chain \| hemagglutinin ha1 chain	SAbDab (2026-04-17)
D [auth L], H [auth F], L [auth K]	Light Chain	IGKV3	Kappa	hemagglutinin ha2 chain \| hemagglutinin ha1 chain	SAbDab (2026-04-17)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, E [auth C], I [auth G]	Hemagglutinin HA1 chain	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
B, F [auth D], J [auth I]	Hemagglutinin HA2 chain	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
C [auth H], G [auth E], K [auth J]	310-39G10 Fab, Heavy Chain	-	-	-
D [auth L], H [auth F], L [auth K]	310-39G10 Fab, Light Chain	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, E [auth C], I [auth G]	IPR001364	Haemagglutinin, influenzavirus A/B	Family
A, E [auth C], I [auth G]	IPR008980	Viral capsid/haemagglutinin protein	Homologous Superfamily
A, E [auth C], I [auth G]	IPR000149	Haemagglutinin, influenzavirus A	Family
A, E [auth C], I [auth G]	IPR013828	Haemagglutinin, HA1 chain, alpha/beta domain superfamily	Homologous Superfamily
B, F [auth D], J [auth I]	IPR001364	Haemagglutinin, influenzavirus A/B	Family
B, F [auth D], J [auth I]	IPR008980	Viral capsid/haemagglutinin protein	Homologous Superfamily
B, F [auth D], J [auth I]	IPR000149	Haemagglutinin, influenzavirus A	Family
B, F [auth D], J [auth I]	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.