Annotations: 2QQA

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d2qqaa1	All alpha proteins	DNA/RNA-binding 3-helical bundle	'Winged helix' DNA-binding domain	Iron-dependent repressor protein	Diphtheria toxin repressor (DtxR)	(Corynebacterium diphtheriae ) [TaxId: 1717 ],	SCOPe (2.08)
A	d2qqaa2	All alpha proteins	Iron-dependent repressor protein, dimerization domain	Iron-dependent repressor protein, dimerization domain	Iron-dependent repressor protein, dimerization domain	Diphtheria toxin repressor (DtxR)	(Corynebacterium diphtheriae ) [TaxId: 1717 ],	SCOPe (2.08)
A	d2qqaa3	All beta proteins	SH3-like barrel	C-terminal domain of transcriptional repressors	FeoA-like	Diphtheria toxin repressor (DtxR)	(Corynebacterium diphtheriae ) [TaxId: 1717 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	Transcriptional regulator domain	8003191	3000121	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Winged helix DNA-binding domain	8003184	3000034	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	DtxR dimerization domain-like	8003186	3000063	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)
A	PF18357	e2qqaA1	A: beta barrels	X: SH3	H: SH3	T: SH3	F: PF18357	ECOD (1.6)
A	PF01325	e2qqaA2	A: alpha arrays	X: HTH	H: HTH	T: winged	F: PF01325	ECOD (1.6)
A	PF02742	e2qqaA3	A: alpha duplicates or obligate multimers	X: Iron-dependent repressor protein, dimerization domain (From Topology)	H: Iron-dependent repressor protein, dimerization domain (From Topology)	T: Iron-dependent repressor protein, dimerization domain	F: PF02742	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.10.10.10	Mainly Alpha	Orthogonal Bundle	Arc Repressor Mutant, subunit A	Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain	CATH (4.3.0)
A	1.10.60.10	Mainly Alpha	Orthogonal Bundle	Diphtheria Toxin Repressor	domain 2	CATH (4.3.0)
A	2.30.30.90	Mainly Beta	Roll	SH3 type barrels.	Ferrous iron transport protein A (FeoA)	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF18357	Diphteria toxin repressor SH3 domain (DtxR)	Diphteria toxin repressor SH3 domain	This is an SH3 domain which can be found in diphtheria toxin repressor (DtxR) proteins. DtxR) from Corynebacterium diphtheriae regulates the expression of the gene on corynebacteriophages that encodes diphtheria toxin (DT). Other genes regulated by D ...	This is an SH3 domain which can be found in diphtheria toxin repressor (DtxR) proteins. DtxR) from Corynebacterium diphtheriae regulates the expression of the gene on corynebacteriophages that encodes diphtheria toxin (DT). Other genes regulated by DtxR include those that encode proteins involved in siderophore-mediated iron uptake [1].	Domain
A	PF02742	Iron dependent repressor, metal binding and dimerisation domain (Fe_dep_repr_C)	Iron dependent repressor, metal binding and dimerisation domain	This family includes the Diphtheria toxin repressor [1]. It acts as an iron-binding repressor of diphtheria toxin gene expression and may serve as a global regulator of gene expression. DTXR comprises an N-terminal DNA-binding domain, an interface do ...	This family includes the Diphtheria toxin repressor [1]. It acts as an iron-binding repressor of diphtheria toxin gene expression and may serve as a global regulator of gene expression. DTXR comprises an N-terminal DNA-binding domain, an interface domain (which contains two metal-binding sites) and a third, very flexible C-terminal domain. The second domain is responsible for dimerization and metal binding. Binding of DTXR to Tox operator requires a divalent metal ion such as cobalt, ferric, manganese and nickel whereas zinc shows weak activation [2]. This domain can also bind Cd(II), Ca(II) and Cu(II) (Matilla et. al., FEMS Microbiology Reviews, fuab043, 45, 2021, 1. https://doi.org/10.1093/femsre/fuab043).	Domain
A	PF01325	Iron dependent repressor, N-terminal DNA binding domain (Fe_dep_repress)	Iron dependent repressor, N-terminal DNA binding domain	This family includes the Diphtheria toxin repressor. DNA binding is through a helix-turn-helix motif.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	Diphtheria toxin repressor	SH3 domain binding protein binding binding protein domain specific binding DNA binding organic cyclic compound binding nucleic acid binding cation binding transition metal ion binding ion binding metal ion binding small molecule binding transcription regulator activity DNA-binding transcription factor activity SH3 domain binding protein binding binding protein domain specific binding DNA binding organic cyclic compound binding nucleic acid binding cation binding transition metal ion binding ion binding metal ion binding small molecule binding transcription regulator activity DNA-binding transcription factor activity protein dimerization activity identical protein binding	-	intracellular anatomical structure cytoplasm cellular anatomical entity

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR036421	Iron dependent repressor, metal binding and dimerisation domain superfamily	Homologous Superfamily
A	IPR022687	DTXR-type HTH domain	Domain
A	IPR022689	Iron dependent repressor	Family
A	IPR001367	Iron dependent repressor, metal binding and dimerisation domain	Domain
A	IPR036388	Winged helix-like DNA-binding domain superfamily	Homologous Superfamily
A	IPR038157	Ferrous iron transporter, core domain	Homologous Superfamily
A	IPR040767	Diphteria toxin repressor, SH3 domain	Domain
A	IPR008988	Transcriptional repressor, C-terminal	Homologous Superfamily
A	IPR036390	Winged helix DNA-binding domain superfamily	Homologous Superfamily
A	IPR007167	Ferrous iron transporter FeoA domain	Domain

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 R01GM133198.