4GAG | pdb_00004gag

Structure of the broadly neutralizing antibody AP33 in complex with its HCV epitope (E2 residues 412-423)

External Resource: Annotation

Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
SAbDab Antibody Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Protein Modification Annotation

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
B [auth L]	V-set	e4gagL1	A: a/b three-layered sandwiches	X: Globin-like	H: Nucleoside diphosphate kinases	T: Nucleoside diphosphate kinases	F: V-set	ECOD (v294.1)
A [auth H]	V-set	e4gagH1	A: a/b three-layered sandwiches	X: Globin-like	H: Nucleoside diphosphate kinases	T: Nucleoside diphosphate kinases	F: V-set	ECOD (v294.1)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B [auth L]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
A [auth H]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)

IMGT Antibody Annotation IMGT Database Homepage

Chain	Protein Name	Description	Organism Name	Gene Allele Name(s)	Domain Name(s)	Receptor Type	Receptor Description	Provenance Source
B [auth L]	AP33 Fab, anti-hepatitis C virus (HCV) envelope glycoprotein E2,	L-KAPPA	Mus musculus (house mouse)	IGKV3-1001, IGKJ101, IGKJ102, IGKC01, IGKC*02	V-DOMAIN V-KAPPA, C-DOMAIN C-KAPPA	IG	FAB-GAMMA-1_KAPPA	IMGT (202612-0)
A [auth H]	AP33 Fab, anti-hepatitis C virus (HCV) envelope glycoprotein E2,	VH-CH1	Mus musculus (house mouse)	IGHV3-802, IGHJ401, IGHG1*02	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_KAPPA	IMGT (202612-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B [auth L]	Light Chain	IGKV3	Kappa	genome polyprotein	SAbDab (2026-03-27)
A [auth H]	Heavy Chain	IGHV3	-	genome polyprotein	SAbDab (2026-03-27)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C [auth P]	Genome polyprotein	cysteine-type peptidase activity peptidase activity catalytic activity, acting on a protein hydrolase activity catalytic activity RNA binding binding nucleic acid binding passive transmembrane transporter activity channel activity transporter activity transmembrane transporter activity structural molecule activity	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 transmembrane transport monoatomic ion transmembrane transport monoatomic ion transport virion attachment to host cell adhesion of symbiont to host cell adhesion of symbiont to host proteolysis metabolic process primary metabolic process protein metabolic process macromolecule metabolic process symbiont-mediated perturbation of host defense response symbiont-mediated suppression of host immune response symbiont-mediated suppression of host innate immune response symbiont-mediated perturbation of host process symbiont-mediated perturbation of host immune response symbiont-mediated perturbation of host innate immune response modulation of process of another organism	host cellular component host intracellular part cellular anatomical structure host cell cytoplasm host cell part host cell lipid droplet host intracellular region other organism part host cell cytoplasm part host intracellular membrane-bounded organelle host cell membrane host cell mitochondrion host intracellular organelle host cell mitochondrial envelope host cellular component host intracellular part cellular anatomical structure host cell cytoplasm host cell part host cell lipid droplet host intracellular region other organism part host cell cytoplasm part host intracellular membrane-bounded organelle host cell membrane host cell mitochondrion host intracellular organelle host cell mitochondrial envelope host cell mitochondrial membrane host cell plasma membrane virion component virion membrane host cell endoplasmic reticulum host cell endomembrane system host cell endoplasmic reticulum membrane host cell nucleus viral membrane viral envelope protein-containing complex ribonucleoprotein complex viral nucleocapsid viral capsid
B [auth L]	NEUTRALIZING ANTIBODY AP33 LIGHT CHAIN	-	-	-
A [auth H]	NEUTRALIZING ANTIBODY AP33 HEAVY CHAIN	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C [auth P]	IPR002522	Hepatitis C virus, Core protein, N-terminal	Domain
C [auth P]	IPR002521	Hepatitis C virus, Core protein, C-terminal	Domain
C [auth P]	IPR002519	Hepatitis C virus, Envelope glycoprotein E1	Domain
C [auth P]	IPR044896	Hepatitis C virus core protein, chain A superfamily	Homologous Superfamily
C [auth P]	IPR049913	Hepatitis C virus, p7 channel	Domain
C [auth P]	IPR002531	Hepatitis C virus, Non-structural protein E2/NS1	Domain

Protein Modification Annotation

Modified Residue(s)
Chain	Residue(s)	Description
C [auth P]	PCA	Parent Component: GLN RESID: AA0031 PSI-MOD : 2-pyrrolidone-5-carboxylic acid (Gln) MOD:00040 , 2-pyrrolidone-5-carboxylic acid (Glu) MOD:00420

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.