Annotations: 2X4H

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
B	Fe_dep_repress	e2x4hB1	A: alpha arrays	X: HTH	H: HTH	T: winged	F: Fe_dep_repress	ECOD (1.6)
B	Fe_dep_repr_C	e2x4hB2	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: Fe_dep_repr_C	ECOD (1.6)
A	Fe_dep_repress	e2x4hA2	A: alpha arrays	X: HTH	H: HTH	T: winged	F: Fe_dep_repress	ECOD (1.6)
A	Fe_dep_repr_C	e2x4hA1	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: Fe_dep_repr_C	ECOD (1.6)
C	Fe_dep_repress	e2x4hC1	A: alpha arrays	X: HTH	H: HTH	T: winged	F: Fe_dep_repress	ECOD (1.6)
C	Fe_dep_repr_C	e2x4hC2	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: Fe_dep_repr_C	ECOD (1.6)
D	Fe_dep_repress	e2x4hD1	A: alpha arrays	X: HTH	H: HTH	T: winged	F: Fe_dep_repress	ECOD (1.6)
D	Fe_dep_repr_C	e2x4hD2	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: Fe_dep_repr_C	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B	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	1.10.10.10	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)
C	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)
D	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)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B, C, D	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, B, C, D	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, B, C, D	HYPOTHETICAL PROTEIN SSO2273	DNA binding binding organic cyclic compound binding nucleic acid binding transcription regulator activity DNA-binding transcription factor activity protein binding protein dimerization activity cation binding transition metal ion binding ion binding metal ion binding small molecule binding	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B, C, D	IPR036421	Iron dependent repressor, metal binding and dimerisation domain superfamily	Homologous Superfamily
A, B, C, D	IPR022687	DTXR-type HTH domain	Domain
A, B, C, D	IPR022689	Iron dependent repressor	Family
A, B, C, D	IPR001367	Iron dependent repressor, metal binding and dimerisation domain	Domain
A, B, C, D	IPR036388	Winged helix-like DNA-binding domain superfamily	Homologous Superfamily
A, B, C, D	IPR050536	DtxR/MntR Metal-Dependent Regulators	Family
A, B, C, D	IPR036390	Winged helix DNA-binding domain superfamily	Homologous Superfamily

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.