Annotations: 9LY5

antibody 20G5 Fab in complex with human B7-H3 (IgC)

External Resource: Annotation

Domain Annotation: ECOD Classification
SAbDab Antibody Annotation
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Pharos: Disease Associations

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
C	C2-set_3	e9ly5C1	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: C2-set_3	ECOD (v295.2)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B	Light Chain	IGKV1	Kappa	cd276 antigen	SAbDab (2026-10-23)
A	Heavy Chain	IGHV1	-	cd276 antigen	SAbDab (2026-10-23)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
C	PF07686	Immunoglobulin V-set domain (V-set)	Immunoglobulin V-set domain	This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.	Domain
C	PF22705	Butyrophilin subfamily 3 member A2-like, Ig-C domain (C2-set_3)	Butyrophilin subfamily 3 member A2-like, Ig-C domain	This domain is found in human Butyrophilin subfamily 3 member A2 (BTN3A2), a protein that plays a role in T-cell responses in the adaptive immune response. BTN3A2 shows two extracellular domains: an N-terminal Ig-V like domain (Pfam:PF07686) and a C- ...	This domain is found in human Butyrophilin subfamily 3 member A2 (BTN3A2), a protein that plays a role in T-cell responses in the adaptive immune response. BTN3A2 shows two extracellular domains: an N-terminal Ig-V like domain (Pfam:PF07686) and a C-terminal Ig-C type domain that is located in the centre of the protein sequence [6].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C	CD276 antigen	protein binding binding signaling receptor binding	multicellular organismal process T cell activation immune system process cell activation cellular process lymphocyte activation leukocyte activation cellular response to stimulus immune response-regulating cell surface receptor signaling pathway regulation of cellular process response to stimulus signaling positive regulation of biological process cell communication multicellular organismal process T cell activation immune system process cell activation cellular process lymphocyte activation leukocyte activation cellular response to stimulus immune response-regulating cell surface receptor signaling pathway regulation of cellular process response to stimulus signaling positive regulation of biological process cell communication positive regulation of response to stimulus immune response-activating signaling pathway immune response-regulating signaling pathway positive regulation of immune response regulation of immune system process signal transduction positive regulation of immune system process regulation of biological process cell surface receptor signaling pathway immune response-activating cell surface receptor signaling pathway immune response biological regulation T cell receptor signaling pathway regulation of response to stimulus regulation of immune response antigen receptor-mediated signaling pathway activation of immune response positive regulation of cell population proliferation regulation of leukocyte activation regulation of cell activation positive regulation of cell activation lymphocyte proliferation positive regulation of leukocyte activation regulation of leukocyte proliferation cell population proliferation positive regulation of T cell activation positive regulation of lymphocyte proliferation positive regulation of T cell proliferation regulation of cell population proliferation mononuclear cell proliferation regulation of leukocyte cell-cell adhesion positive regulation of leukocyte proliferation positive regulation of multicellular organismal process positive regulation of leukocyte cell-cell adhesion leukocyte proliferation leukocyte cell-cell adhesion positive regulation of cell-cell adhesion positive regulation of lymphocyte activation cell adhesion cell-cell adhesion positive regulation of mononuclear cell proliferation regulation of multicellular organismal process regulation of cell-cell adhesion positive regulation of cellular process T cell proliferation regulation of lymphocyte proliferation positive regulation of cell adhesion regulation of cell adhesion regulation of T cell activation regulation of T cell proliferation regulation of mononuclear cell proliferation regulation of lymphocyte activation regulation of type II interferon production type II interferon production positive regulation of macromolecule biosynthetic process positive regulation of metabolic process positive regulation of biosynthetic process cytokine production regulation of cytokine production positive regulation of macromolecule metabolic process regulation of biosynthetic process regulation of macromolecule metabolic process gene expression macromolecule biosynthetic process positive regulation of type II interferon production regulation of gene expression biosynthetic process positive regulation of gene expression metabolic process regulation of macromolecule biosynthetic process macromolecule metabolic process positive regulation of cytokine production regulation of metabolic process	cell periphery cellular anatomical structure cell surface membrane plasma membrane external side of plasma membrane side of membrane
B	antibody 20G5 Fab light chain	-	-	-
A	antibody 20G5 Fab heavy chain	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
C	IPR003598	Immunoglobulin subtype 2	Domain
C	IPR050504	BTN/MOG-like	Family
C	IPR003597	Immunoglobulin C1-set	Domain
C	IPR053896	Butyrophilin subfamily 3 member A2-like, Ig-C domain	Domain
C	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
C	IPR013106	Immunoglobulin V-set domain	Domain
C	IPR003599	Immunoglobulin domain subtype	Domain
C	IPR007110	Immunoglobulin-like domain	Domain
C	IPR047318	CD276 antigen-like, IgV domain	Domain

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
C	: Q5ZPR3	Liver Cirrhosis, Experimental attention deficit hyperactivity disorder, inattentive type breast cancer endogenous depression hepatocellular carcinoma malignant glioma pancreatic ductal adenocarcinoma atypical teratoid rhabdoid tumor cancer medulloblastoma primitive neuroectodermal tumor autoimmune disease chronic obstructive pulmonary disease glioblastoma osteosarcoma Liver Cirrhosis, Experimental attention deficit hyperactivity disorder, inattentive type breast cancer endogenous depression hepatocellular carcinoma malignant glioma pancreatic ductal adenocarcinoma atypical teratoid rhabdoid tumor cancer medulloblastoma primitive neuroectodermal tumor autoimmune disease chronic obstructive pulmonary disease glioblastoma osteosarcoma subependymal giant cell astrocytoma