Annotations: 6B9Y

Trastuzumab Fab v3 in complex with 5-phenyl meditope variant

External Resource: Annotation

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

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
D [auth C]	e6b9yC1	A: alpha arrays	X: Major facilitator superfamily (MFS) general substrate transporter	H: Major facilitator superfamily (MFS) general substrate transporter	T: Major facilitator superfamily (MFS) general substrate transporter	F:	ECOD (v295.2)
C [auth E]	e6b9yE1	A: alpha arrays	X: Major facilitator superfamily (MFS) general substrate transporter	H: Major facilitator superfamily (MFS) general substrate transporter	T: Major facilitator superfamily (MFS) general substrate transporter	F:	ECOD (v295.2)
B	e6b9yB1	A: alpha arrays	X: Major facilitator superfamily (MFS) general substrate transporter	H: Major facilitator superfamily (MFS) general substrate transporter	T: Major facilitator superfamily (MFS) general substrate transporter	F:	ECOD (v295.2)
A	e6b9yA1	A: alpha arrays	X: Major facilitator superfamily (MFS) general substrate transporter	H: Major facilitator superfamily (MFS) general substrate transporter	T: Major facilitator superfamily (MFS) general substrate transporter	F:	ECOD (v295.2)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
D [auth C]	1.20.5.420	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Immunoglobulin FC, subunit C	CATH (4.3.0)
C [auth E]	3.10.20.10	Alpha Beta	Roll	Ubiquitin-like (UB roll)		CATH (4.3.0)
B	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)
A	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B	Heavy Chain	IGHV3	-	immunoglobulin g binding protein a \| protein l	SAbDab (2026-10-16)
A	Light Chain	IGKV1	Kappa	immunoglobulin g binding protein a \| protein l	SAbDab (2026-10-16)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
D [auth C]	PF02216	B domain (B)	B domain	This family contains the B domain of Staphylococcal protein A, which specifically binds to the Fc portion of immunoglobulin G.	Domain
A	PF07654	Immunoglobulin C1-set domain (C1-set)	Immunoglobulin C1-set domain		Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
E [auth D]	meditope	-	-	-
D [auth C]	Immunoglobulin G binding protein A	-	-	-
C [auth E]	Protein L	protein-containing complex binding binding immunoglobulin binding IgG binding	-	-
B	Trastuzumab Fab heavy chain	-	-	cell periphery cellular anatomical structure plasma membrane membrane extracellular region
A	Trastuzumab Fab light chain	binding antigen binding	adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains lymphocyte mediated immunity response to stimulus immune response immune system process B cell mediated immunity leukocyte mediated immunity immunoglobulin mediated immune response adaptive immune response immune effector process cellular response to stimulus immune response-regulating cell surface receptor signaling pathway regulation of cellular process signaling adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains lymphocyte mediated immunity response to stimulus immune response immune system process B cell mediated immunity leukocyte mediated immunity immunoglobulin mediated immune response adaptive immune response immune effector process cellular response to stimulus immune response-regulating cell surface receptor signaling pathway regulation of cellular process 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 B cell receptor signaling pathway biological regulation regulation of response to stimulus regulation of immune response cellular process antigen receptor-mediated signaling pathway activation of immune response	protein-containing complex IgA immunoglobulin complex immunoglobulin complex cellular anatomical structure extracellular region blood microparticle IgM immunoglobulin complex IgE immunoglobulin complex IgD immunoglobulin complex extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle organelle protein-containing complex IgA immunoglobulin complex immunoglobulin complex cellular anatomical structure extracellular region blood microparticle IgM immunoglobulin complex IgE immunoglobulin complex IgD immunoglobulin complex extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle organelle vesicle extracellular membrane-bounded organelle cell periphery plasma membrane membrane IgG immunoglobulin complex

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C [auth E]	IPR009063	Immunoglobulin/albumin-binding domain superfamily	Homologous Superfamily
C [auth E]	IPR020840	Extracellular matrix-binding protein ebh, GA module	Domain
C [auth E]	IPR003147	Protein L, Ig light chain-binding	Repeat
C [auth E]	IPR040912	Repeat of unknown function DUF5633	Repeat
C [auth E]	IPR002988	Protein G-related albumin-binding (GA) module	Domain
C [auth E]	IPR035152	GA-like domain	Domain
C [auth E]	IPR019931	LPXTG cell wall anchor motif	Conserved Site
B	IPR003597	Immunoglobulin C1-set	Domain
B	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
B	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
B	IPR013106	Immunoglobulin V-set domain	Domain
B	IPR003599	Immunoglobulin domain subtype	Domain
B	IPR007110	Immunoglobulin-like domain	Domain
B	IPR050380	Immune Recognition and Response Modulators	Family
B	IPR003006	Immunoglobulin/major histocompatibility complex, conserved site	Conserved Site
A	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
A	IPR050380	Immune Recognition and Response Modulators	Family
A	IPR003597	Immunoglobulin C1-set	Domain
A	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
A	IPR007110	Immunoglobulin-like domain	Domain
A	IPR003006	Immunoglobulin/major histocompatibility complex, conserved site	Conserved Site

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A	: P01834	recurrent infections associated with rare immunoglobulin isotypes deficiency myositis dysgammaglobulinemia Hepatomegaly acquired idiopathic inflammatory myopathy selective IgG immunodeficiency

Protein Modification Annotation

Modified Residue(s)
Chain	Residue(s)	Description
E [auth D]	ACE	: AA0041 , AA0042 , AA0043 , AA0044 , AA0045 , AA0046 , AA0049 , AA0050 , AA0051 , AA0052 , AA0053 , AA0054 , AA0354 : N-acetyl-L-alanine MOD:00050 , N-acetyl-L-aspartic acid MOD:00051 , N-acetyl-L-cysteine MOD:00052 , N-acetyl-S-archeol-cysteine MOD:00897 , N-acetyl-L-glutamic acid MOD:00053 , N-acetyl-L-glutamine MOD:00054 , N-acetylglycine MOD:00055 , N-acetyl-L-methionine MOD:00058 , N-acetyl-L-proline MOD:00059 , N-acetyl-L-serine MOD:00060 , N,O-diacetylated L-serine MOD:00648 , N-acetyl-L-threonine MOD:00061 , N-acetyl-L-tyrosine MOD:00062 , N-acetyl-L-valine MOD:00063 , N2-acetyl-L-arginine MOD:00359