Annotations: 8K3C

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
D [auth B]	SCOP2B Superfamily	Sialidases	8086578	3001607	SCOP2B (2022-06-29)
C [auth A]	SCOP2B Superfamily	Sialidases	8086578	3001607	SCOP2B (2022-06-29)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B [auth C]	Heavy Chain	IGHV3	-	glycoprotein g	SAbDab (2025-11-28)
A [auth D]	Light Chain	IGLV1	Lambda	glycoprotein g	SAbDab (2025-11-28)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
C [auth A], D [auth B]	PF00423	Haemagglutinin-neuraminidase (HN)	Haemagglutinin-neuraminidase	-	Repeat

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C [auth A], D [auth B]	Glycoprotein G	identical protein binding protein binding binding hydrolase activity, acting on glycosyl bonds alpha-sialidase activity hydrolase activity, hydrolyzing O-glycosyl compounds hydrolase activity exo-alpha-sialidase activity catalytic activity host cell surface binding host cell surface receptor binding	viral process membrane fusion involved in viral entry into host cell 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 import into cell receptor-mediated endocytosis of virus by host cell transport establishment of localization vesicle-mediated transport viral process membrane fusion involved in viral entry into host cell 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 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 cellular process 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 [auth C]	Heavy chain of 41-6 Fab fragments	-	-	-
A [auth D]	Light chain of 41-6 Fab fragment	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C [auth A], D [auth B]	IPR016285	Haemagglutinin-neuraminidase	Family
C [auth A], D [auth B]	IPR036278	Sialidase superfamily	Homologous Superfamily
C [auth A], D [auth B]	IPR000665	Haemagglutinin/haemagglutinin-neuraminidase, paramyxovirus	Family

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.