Annotations: 9OSR

Structure of Fab HB420 in complex with influenza H3N2 A/Moscow/10/1999 neuraminidase

External Resource: Annotation

Domain Annotation: ECOD Classification
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)
D	Cofilin_ADF	e9osrD1	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: Cofilin_ADF	ECOD (v295.2)
C	Cofilin_ADF	e9osrC1	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: Cofilin_ADF	ECOD (v295.2)
B	Cofilin_ADF	e9osrB1	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: Cofilin_ADF	ECOD (v295.2)
A	Cofilin_ADF	e9osrA1	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: Cofilin_ADF	ECOD (v295.2)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
E [auth J], F [auth H], H [auth K], K [auth I]	Heavy Chain	IGHV1	-	neuraminidase	SAbDab (2026-08-28)
G [auth N], I [auth L], J [auth R], L [auth M]	Light Chain	IGLV2	Lambda	neuraminidase	SAbDab (2026-08-28)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B, C, D	Neuraminidase	cation binding ion binding binding metal ion binding small molecule binding hydrolase activity, acting on glycosyl bonds alpha-sialidase activity hydrolase activity, hydrolyzing O-glycosyl compounds hydrolase activity exo-alpha-sialidase activity catalytic activity	carbohydrate metabolic process primary metabolic process metabolic process cellular process biological process involved in interspecies interaction between organisms non-lytic viral release viral budding viral life cycle biological process involved in interaction with host biological process involved in symbiotic interaction virion assembly exit from host cell viral process viral budding from plasma membrane carbohydrate metabolic process primary metabolic process metabolic process cellular process biological process involved in interspecies interaction between organisms non-lytic viral release viral budding viral life cycle biological process involved in interaction with host biological process involved in symbiotic interaction virion assembly exit from host cell viral process viral budding from plasma membrane viral release from host cell	cellular anatomical structure membrane host cell plasma membrane host cellular component host cell part host cell membrane other organism part virion component virion membrane
E [auth J], F [auth H], H [auth K], K [auth I]	Variable domain of the heavy chain of Fab hb420	-	-	-
G [auth N], I [auth L], J [auth R], L [auth M]	Variable domain of the light chain of Fab HB420	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B, C, D	IPR001860	Glycoside hydrolase, family 34	Family
A, B, C, D	IPR033654	Sialidase, Influenza viruses A/B	Domain
A, B, C, D	IPR036278	Sialidase superfamily	Homologous Superfamily

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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.

9OSR | pdb_00009osr

Structure of Fab HB420 in complex with influenza H3N2 A/Moscow/10/1999 neuraminidase

External Resource: Annotation

Domain Annotation: ECOD Classification ECOD Database Homepage

SAbDab Antibody Annotation SAbDab Database Homepage

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

InterPro: Protein Family Classification InterPro Database Homepage