Annotations: 3OD2

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d3od2a1	All alpha proteins	Ribbon-helix-helix	Ribbon-helix-helix	CopG-like	Nickel responsive regulator NikR, N-terminal domain	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
A	d3od2a2	Alpha and beta proteins (a+b)	Ferredoxin-like	ACT-like	Nickel responsive regulator NikR, C-terminal domain	Nickel responsive regulator NikR, C-terminal domain	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
B	d3od2b1	All alpha proteins	Ribbon-helix-helix	Ribbon-helix-helix	CopG-like	Nickel responsive regulator NikR, N-terminal domain	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
B	d3od2b2	Alpha and beta proteins (a+b)	Ferredoxin-like	ACT-like	Nickel responsive regulator NikR, C-terminal domain	Nickel responsive regulator NikR, C-terminal domain	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	ACT-like	8039824	3000006	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Ribbon-helix-helix	8042504	3000295	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	ACT-like	8039824	3000006	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Ribbon-helix-helix	8042504	3000295	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	RHH_1_1	e3od2A1	A: alpha arrays	X: HTH	H: HTH	T: Ribbon-helix-helix	F: RHH_1_1	ECOD (1.6)
A	NikR_C	e3od2A2	A: a+b two layers	X: Alpha-beta plaits	H: ACT-like (From Topology)	T: ACT-like	F: NikR_C	ECOD (1.6)
B	RHH_1_1	e3od2B4	A: alpha arrays	X: HTH	H: HTH	T: Ribbon-helix-helix	F: RHH_1_1	ECOD (1.6)
B	NikR_C	e3od2B3	A: a+b two layers	X: Alpha-beta plaits	H: ACT-like (From Topology)	T: ACT-like	F: NikR_C	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.10.1220.10	Mainly Alpha	Orthogonal Bundle	Arc Repressor Mutant	Met repressor-like	CATH (4.3.0)
A	3.30.70.1150	Alpha Beta	2-Layer Sandwich	Alpha-Beta Plaits	ACT-like. Chain A, domain 2	CATH (4.3.0)
B	1.10.1220.10	Mainly Alpha	Orthogonal Bundle	Arc Repressor Mutant	Met repressor-like	CATH (4.3.0)
B	3.30.70.1150	Alpha Beta	2-Layer Sandwich	Alpha-Beta Plaits	ACT-like. Chain A, domain 2	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B	PF08753	NikR C terminal nickel binding domain (NikR_C)	NikR C terminal nickel binding domain	NikR is a transcription factor that regulates nickel uptake. It consists of two dimeric DNA binding domains separated by a tetrameric regulatory domain that binds nickel. This domain corresponds to the C terminal regulatory domain which contains fou ...	NikR is a transcription factor that regulates nickel uptake. It consists of two dimeric DNA binding domains separated by a tetrameric regulatory domain that binds nickel. This domain corresponds to the C terminal regulatory domain which contains four nickel binding sites at the tetramer interface [1].	Domain
A, B	PF01402	Ribbon-helix-helix protein, copG family (RHH_1)	Ribbon-helix-helix protein, copG family	The structure of this protein repressor, which is the shortest reported to date and the first isolated from a plasmid, has a homodimeric ribbon-helix-helix arrangement [2]. The helix-turn-helix-like structure is involved in dimerisation and not DNA b ...	The structure of this protein repressor, which is the shortest reported to date and the first isolated from a plasmid, has a homodimeric ribbon-helix-helix arrangement [2]. The helix-turn-helix-like structure is involved in dimerisation and not DNA binding as might have been expected [2].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	Nickel-responsive regulatory protein	DNA binding binding organic cyclic compound binding nucleic acid binding cation binding transition metal ion binding ion binding nickel cation binding metal ion binding small molecule binding sequence-specific DNA binding sequence-specific double-stranded DNA binding transcription cis-regulatory region binding double-stranded DNA binding DNA binding binding organic cyclic compound binding nucleic acid binding cation binding transition metal ion binding ion binding nickel cation binding metal ion binding small molecule binding sequence-specific DNA binding sequence-specific double-stranded DNA binding transcription cis-regulatory region binding double-stranded DNA binding transcription regulatory region nucleic acid binding core promoter sequence-specific DNA binding identical protein binding protein binding transcription regulator activity DNA-binding transcription repressor activity DNA-binding transcription factor activity	regulation of cellular process cellular biosynthetic process RNA metabolic process regulation of primary metabolic process nucleobase-containing compound metabolic process RNA biosynthetic process nucleic acid biosynthetic process DNA-templated transcription regulation of RNA metabolic process organic substance metabolic process organic substance biosynthetic process regulation of nucleobase-containing compound metabolic process regulation of RNA biosynthetic process regulation of biosynthetic process regulation of cellular process cellular biosynthetic process RNA metabolic process regulation of primary metabolic process nucleobase-containing compound metabolic process RNA biosynthetic process nucleic acid biosynthetic process DNA-templated transcription regulation of RNA metabolic process organic substance metabolic process organic substance biosynthetic process regulation of nucleobase-containing compound metabolic process regulation of RNA biosynthetic process regulation of biosynthetic process regulation of biological process cellular metabolic process biological regulation primary metabolic process regulation of cellular metabolic process regulation of macromolecule metabolic process nucleobase-containing compound biosynthetic process gene expression macromolecule biosynthetic process nucleic acid metabolic process regulation of cellular biosynthetic process organic cyclic compound metabolic process regulation of gene expression biosynthetic process organic cyclic compound biosynthetic process metabolic process regulation of macromolecule biosynthetic process cellular process regulation of DNA-templated transcription macromolecule metabolic process regulation of metabolic process negative regulation of biological process negative regulation of cellular metabolic process negative regulation of RNA biosynthetic process regulation of DNA-templated transcription initiation negative regulation of nucleobase-containing compound metabolic process negative regulation of DNA-templated transcription negative regulation of metabolic process negative regulation of cellular biosynthetic process negative regulation of macromolecule biosynthetic process negative regulation of RNA metabolic process negative regulation of cellular process negative regulation of macromolecule metabolic process DNA-templated transcription initiation negative regulation of biosynthetic process negative regulation of DNA-templated transcription initiation response to stimulus response to metal ion response to chemical response to nickel cation response to inorganic substance	protein-containing complex transcription regulator complex protein-DNA complex

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR014160	Nickel-responsive transcriptional regulator NikR, proteobacteria	Family
A, B	IPR022988	Nickel-responsive transcriptional regulator NikR	Family
A, B	IPR010985	Ribbon-helix-helix	Homologous Superfamily
A, B	IPR027271	Acetolactate synthase/Transcription factor NikR, C-terminal	Homologous Superfamily
A, B	IPR045865	ACT-like domain	Homologous Superfamily
A, B	IPR014864	Transcription factor, NikR, nickel binding C-terminal	Domain
A, B	IPR013321	Arc-type ribbon-helix-helix	Homologous Superfamily
A, B	IPR002145	Ribbon-helix-helix protein, CopG	Domain

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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.