Annotations: 5I9Q

Crystal structure of 3BNC55 Fab in complex with 426c.TM4deltaV1-3 gp120

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
IMGT Antibody Annotation
SAbDab Antibody Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification

Domain Annotation: SCOP/SCOPe Classification SCOP-e Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
E [auth H]	d5i9qh_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	Human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
C [auth B]	d5i9qb_	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	Human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
F [auth L]	d5i9ql2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	Human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
F [auth L]	d5i9ql1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	Human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D [auth C]	d5i9qc2	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	C1 set domains (antibody constant domain-like)	automated matches	Human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D [auth C]	d5i9qc1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	Human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	Ribosomal_S5_C	e5i9qA1	A: beta barrels	X: HAD domain-like	H: Hemagglutinin HA2 chain	T: Hemagglutinin HA2 chain	F: Ribosomal_S5_C	ECOD (v294.2)
B [auth G]	Ribosomal_S5_C	e5i9qG1	A: beta barrels	X: HAD domain-like	H: Hemagglutinin HA2 chain	T: Hemagglutinin HA2 chain	F: Ribosomal_S5_C	ECOD (v294.2)
E [auth H]	DHHA1	e5i9qH1	A: beta barrels	X: alpha/beta knot	H: alpha/beta knot	T: alpha/beta knot	F: DHHA1	ECOD (v294.2)
C [auth B]	DHHA1	e5i9qB1	A: beta barrels	X: alpha/beta knot	H: alpha/beta knot	T: alpha/beta knot	F: DHHA1	ECOD (v294.2)
F [auth L]	DHHA1	e5i9qL1	A: beta barrels	X: alpha/beta knot	H: alpha/beta knot	T: alpha/beta knot	F: DHHA1	ECOD (v294.2)
D [auth C]	DHHA1	e5i9qC1	A: beta barrels	X: alpha/beta knot	H: alpha/beta knot	T: alpha/beta knot	F: DHHA1	ECOD (v294.2)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	2.170.40.20	Mainly Beta	Beta Complex	HIV Envelope Protein Gp120	Chain G	CATH (4.3.0)
B [auth G]	2.170.40.20	Mainly Beta	Beta Complex	HIV Envelope Protein Gp120	Chain G	CATH (4.3.0)
E [auth H]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
C [auth B]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
F [auth L]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
D [auth C]	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
C [auth B], E [auth H]	3BNC55 Fab	VH-CH1	Homo sapiens (human)	IGHV1-202, IGHJ302, IGHG1*03	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_KAPPA	IMGT (202617-0)
D [auth C], F [auth L]	3BNC55 Fab	L-KAPPA	Homo sapiens (human)	IGKV1-3301, IGKV1D-3301, IGKJ301, IGKJ501, IGKC*01	V-DOMAIN V-KAPPA, C-DOMAIN C-KAPPA	IG	FAB-GAMMA-1_KAPPA	IMGT (202617-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
D [auth C], F [auth L]	Light Chain	IGKV1	Kappa	426c.tm4dv1-3 p120	SAbDab (2026-05-08)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B [auth G]	426c.TM4dV1-3 p120	structural molecule activity	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 regulation of localization regulation of biological process cellular localization regulation of cellular process regulation of protein localization 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 regulation of localization regulation of biological process cellular localization regulation of cellular process regulation of protein localization positive regulation of receptor clustering biological regulation positive regulation of biological process positive regulation of protein localization to membrane localization within membrane protein localization to membrane localization regulation of cellular localization macromolecule localization receptor clustering positive regulation of protein localization intracellular protein localization regulation of receptor clustering regulation of protein localization to membrane positive regulation of cellular process 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 plasma membrane raft distribution regulation of cellular component organization positive regulation of cellular component organization plasma membrane raft polarization plasma membrane organization membrane raft organization endomembrane system organization membrane raft distribution plasma membrane raft localization membrane raft polarization regulation of plasma membrane raft polarization membrane raft localization regulation of plasma membrane organization positive regulation of plasma membrane raft polarization import into cell receptor-mediated endocytosis of virus by host cell transport establishment of localization vesicle-mediated transport 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 viral gene expression viral protein processing symbiont-mediated perturbation of host defense response symbiont-mediated perturbation of host process modulation of process of another organism	cellular anatomical structure membrane virion component virion membrane host intracellular membrane-bounded organelle host cellular component host intracellular part host cell membrane other organism part host cell cytoplasm part host intracellular organelle host cell endosome membrane host cell cytoplasm host cell part cellular anatomical structure membrane virion component virion membrane host intracellular membrane-bounded organelle host cellular component host intracellular part host cell membrane other organism part host cell cytoplasm part host intracellular organelle host cell endosome membrane host cell cytoplasm host cell part host cell endosome host intracellular region viral membrane viral envelope host cell plasma membrane
C [auth B], E [auth H]	3BNC55 Fab heavy chain	-	-	-
D [auth C], F [auth L]	3BNC55 light chain	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B [auth G]	IPR000777	Human immunodeficiency virus 1, envelope glycoprotein Gp120	Domain
A, B [auth G]	IPR036377	Gp120 core superfamily	Homologous Superfamily
A, B [auth G]	IPR000328	Retroviral envelope protein GP41-like	Domain
A, B [auth G]	IPR037527	Envelope glycoprotein Gp160	Family

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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.