Annotations: 6C9U

Crystal structure of [KS3][AT3] didomain from module 3 of 6-deoxyerthronolide B synthase in complex with antibody fragment (Fab)

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: SCOP2 Classification
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: SCOP/SCOPe Classification SCOP-e Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
B [auth L]	d6c9ul1	All beta proteins	Immunoglobulin-like beta-sandwich	Immunoglobulin	automated matches	automated matches	Human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	KASAT domain-like	8055827	3002319	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	FabD/lysophospholipase-like	8055831	3001121	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	KASAT domain-like	8055827	3002319	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Thiolase-like	8055829	3000122	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	FabD/lysophospholipase-like	8055831	3001121	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Probable ACP-binding domain of malonyl-CoA ACP transacylase	8055834	3001224	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
C [auth H]	Complex1_49kDa	e6c9uH1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleotidyltransferase	F: Complex1_49kDa	ECOD (v295.2)
B [auth L]	Complex1_49kDa	e6c9uL1	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleotidyltransferase	F: Complex1_49kDa	ECOD (v295.2)
A	Pept_tRNA_hydro	e6c9uA2	A: alpha arrays	X: OB-fold	H: Nucleic acid-binding protein	T: Nucleotidyltransferase	F: Pept_tRNA_hydro	ECOD (v295.2)
A	7tm_1	e6c9uA6	A: alpha arrays	X: putative RnfG subunit of electron transport complex	H: putative RnfG subunit of electron transport complex	T: Class I glutamine amidotransferase-like	F: 7tm_1	ECOD (v295.2)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
C [auth H]	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
B [auth L]	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 H]	Fab 1B2	VH-CH1	Homo sapiens (human)	IGHV3-4904, IGHJ401, IGHJ402, IGHJ403, IGHG101, IGHG102, IGHG104, IGHG105	V-DOMAIN VH, C-DOMAIN CH1	IG	FAB-GAMMA-1_KAPPA	IMGT (202636-0)
B [auth L]	Fab 1B2	L-KAPPA	Homo sapiens (human)	IGKV2-2801, IGKV2D-2801, IGKJ301, IGKC01	V-DOMAIN V-KAPPA, C-DOMAIN C-KAPPA	IG	FAB-GAMMA-1_KAPPA	IMGT (202636-0)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
C [auth H]	Heavy Chain	IGHV3	-	6-deoxyerythronolide-b synthase erya2, modules 3 and 4	SAbDab (2026-09-18)
B [auth L]	Light Chain	IGKV2	Kappa	6-deoxyerythronolide-b synthase erya2, modules 3 and 4	SAbDab (2026-09-18)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C [auth H]	Heavy chain of Fab 1B2	-	-	-
B [auth L]	Light chain of Fab 1B2	-	-	-
A	6-deoxyerythronolide-B synthase EryA2, modules 3 and 4	oxidoreductase activity catalytic activity vitamin binding modified amino acid binding binding ion binding anion binding phosphopantetheine binding sulfur compound binding small molecule binding acyltransferase activity 3-oxoacyl-[acyl-carrier-protein] synthase activity acyltransferase activity, transferring groups other than amino-acyl groups transferase activity oxidoreductase activity catalytic activity vitamin binding modified amino acid binding binding ion binding anion binding phosphopantetheine binding sulfur compound binding small molecule binding acyltransferase activity 3-oxoacyl-[acyl-carrier-protein] synthase activity acyltransferase activity, transferring groups other than amino-acyl groups transferase activity erythronolide synthase activity fatty acid synthase activity	fatty acid metabolic process monocarboxylic acid biosynthetic process small molecule biosynthetic process oxoacid metabolic process carboxylic acid metabolic process lipid biosynthetic process primary metabolic process fatty acid biosynthetic process carboxylic acid biosynthetic process biosynthetic process small molecule metabolic process metabolic process cellular process monocarboxylic acid metabolic process fatty acid metabolic process monocarboxylic acid biosynthetic process small molecule biosynthetic process oxoacid metabolic process carboxylic acid metabolic process lipid biosynthetic process primary metabolic process fatty acid biosynthetic process carboxylic acid biosynthetic process biosynthetic process small molecule metabolic process metabolic process cellular process monocarboxylic acid metabolic process lipid metabolic process macrolide biosynthetic process polyketide metabolic process macrolide metabolic process secondary metabolic process antibiotic biosynthetic process antibiotic metabolic process polyketide biosynthetic process secondary metabolite biosynthetic process lactone metabolic process lactone biosynthetic process	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR016035	Acyl transferase/acyl hydrolase/lysophospholipase	Homologous Superfamily
A	IPR015083	Polyketide synthase NorB/C/GfsB-E-like, docking domain	Domain
A	IPR006162	Phosphopantetheine attachment site	PTM
A	IPR013154	Alcohol dehydrogenase-like, N-terminal	Domain
A	IPR057326	Ketoreductase domain	Domain
A	IPR036347	Erythronolide synthase, docking domain superfamily	Homologous Superfamily
A	IPR014030	Beta-ketoacyl synthase-like, N-terminal domain	Domain
A	IPR049552	Polyketide synthase, dehydratase domain, N-terminal	Domain
A	IPR049900	Polyketide synthase, dehydratase domain	Domain
A	IPR049551	Polyketide synthase, dehydratase domain, C-terminal	Domain
A	IPR016036	Malonyl-CoA ACP transacylase, ACP-binding	Homologous Superfamily
A	IPR050091	Polyketide and Nonribosomal Peptide Biosynthesis Enzymes	Family
A	IPR020841	Polyketide synthase, beta-ketoacyl synthase domain	Domain
A	IPR020807	Polyketide/metazoan fatty acid synthase-like, dehydratase domain	Domain
A	IPR036736	ACP-like superfamily	Homologous Superfamily
A	IPR014043	Acyl transferase domain	Domain
A	IPR020843	Enoylreductase domain	Domain
A	IPR014031	Beta-ketoacyl synthase, C-terminal domain	Domain
A	IPR032821	Polyketide synthase, C-terminal extension	Domain
A	IPR011032	GroES-like superfamily	Homologous Superfamily
A	IPR009081	Phosphopantetheine binding ACP domain	Domain
A	IPR020806	Polyketide synthase-like, phosphopantetheine-binding domain	Domain
A	IPR015357	EryA2-like, docking domain	Domain
A	IPR013968	Polyketide synthase-like, ketoreductase domain	Domain
A	IPR016039	Thiolase-like	Homologous Superfamily
A	IPR001227	Acyl transferase domain superfamily	Homologous Superfamily
A	IPR036291	NAD(P)-binding domain superfamily	Homologous Superfamily
A	IPR018201	Beta-ketoacyl synthase, active site	Active Site
A	IPR042104	Polyketide synthase, dehydratase domain superfamily	Homologous Superfamily
A	IPR055123	Polyketide synthase extender module SpnB-like, Rossmann fold domain	Domain