Annotations: 1A0A

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
D [auth B]	d1a0ab_	All alpha proteins	HLH-like	HLH, helix-loop-helix DNA-binding domain	HLH, helix-loop-helix DNA-binding domain	Pho4 B/HLH domain	baker's yeast (Saccharomyces cerevisiae ) [TaxId: 4932 ],	SCOPe (2.08)
C [auth A]	d1a0aa_	All alpha proteins	HLH-like	HLH, helix-loop-helix DNA-binding domain	HLH, helix-loop-helix DNA-binding domain	Pho4 B/HLH domain	baker's yeast (Saccharomyces cerevisiae ) [TaxId: 4932 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
D [auth B]	SCOP2B Superfamily	HLH, helix-loop-helix DNA-binding domain	8037250	3001962	SCOP2B (2022-06-29)
C [auth A]	SCOP2 Family	HLH, helix-loop-helix DNA-binding domain	8024871	4000913	SCOP2 (2022-06-29)
C [auth A]	SCOP2 Superfamily	HLH, helix-loop-helix DNA-binding domain	8037250	3001962	SCOP2 (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
D [auth B]	SinI	e1a0aB1	A: a/b three-layered sandwiches	X: Repetitive alpha hairpins	H: ARM repeat	T: ARM repeat	F: SinI	ECOD (v294.1)
C [auth A]	HLH	e1a0aA1	A: alpha bundles	X: HLH-like	H: HLH, helix-loop-helix DNA-binding domain	T: HLH, helix-loop-helix DNA-binding domain	F: HLH	ECOD (v294.1)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
D [auth B]	4.10.280.10	Few Secondary Structures	Irregular	MYOD Basic-Helix-Loop-Helix Domain, subunit B	Helix-loop-helix DNA-binding domain	CATH (4.3.0)
C [auth A]	4.10.280.10	Few Secondary Structures	Irregular	MYOD Basic-Helix-Loop-Helix Domain, subunit B	Helix-loop-helix DNA-binding domain	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
C [auth A], D [auth B]	PF00010	Helix-loop-helix DNA-binding domain (HLH)	Helix-loop-helix DNA-binding domain		Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C [auth A], D [auth B]	PROTEIN (PHOSPHATE SYSTEM POSITIVE REGULATORY PROTEIN PHO4)	transcription regulator activity DNA-binding transcription factor activity protein binding binding protein dimerization activity sequence-specific DNA binding DNA binding nucleic acid binding	regulation of cellular process negative regulation of biological process RNA metabolic process regulation of primary metabolic process negative regulation of RNA biosynthetic process RNA biosynthetic process nucleobase-containing compound metabolic process DNA-templated transcription nucleic acid biosynthetic process regulation of RNA metabolic process transcription by RNA polymerase II negative regulation of cellular process negative regulation of nucleobase-containing compound metabolic process regulation of nucleobase-containing compound metabolic process regulation of cellular process negative regulation of biological process RNA metabolic process regulation of primary metabolic process negative regulation of RNA biosynthetic process RNA biosynthetic process nucleobase-containing compound metabolic process DNA-templated transcription nucleic acid biosynthetic process regulation of RNA metabolic process transcription by RNA polymerase II negative regulation of cellular process negative regulation of nucleobase-containing compound metabolic process regulation of nucleobase-containing compound metabolic process regulation of RNA biosynthetic process negative regulation of macromolecule metabolic process regulation of biosynthetic process regulation of transcription by RNA polymerase II negative regulation of DNA-templated transcription regulation of biological process negative regulation of transcription by RNA polymerase II negative regulation of metabolic process biological regulation primary metabolic process regulation of macromolecule metabolic process nucleobase-containing compound biosynthetic process gene expression macromolecule biosynthetic process nucleic acid metabolic process regulation of gene expression biosynthetic process negative regulation of biosynthetic process negative regulation of macromolecule biosynthetic process metabolic process cellular process regulation of macromolecule biosynthetic process macromolecule metabolic process regulation of DNA-templated transcription regulation of metabolic process negative regulation of RNA metabolic process positive regulation of phosphorus metabolic process positive regulation of biological process positive regulation of phosphate metabolic process positive regulation of metabolic process phosphate-containing compound metabolic process regulation of phosphorus metabolic process phosphorus metabolic process positive regulation of cellular process positive regulation of DNA-templated transcription positive regulation of macromolecule biosynthetic process positive regulation of biosynthetic process positive regulation of macromolecule metabolic process positive regulation of transcription by RNA polymerase II positive regulation of RNA metabolic process positive regulation of RNA biosynthetic process cellular response to stimulus cellular response to nutrient levels response to nutrient levels cellular response to phosphate starvation response to stimulus cellular response to stress response to stress response to starvation cellular response to starvation cellular component organization chromatin organization chromatin remodeling cellular component organization or biogenesis	cellular anatomical structure intracellular anatomical structure cytoplasm membrane-bounded organelle intracellular organelle organelle nucleus intracellular membrane-bounded organelle
B [auth D]	DNA (5'-D(CPTPAPGPTPCPCPCPAPCPGPTPGPTPGPAP*G )-3')	-	-	-
A [auth C]	DNA (5'-D(CPTPCPAPCPAPCPGPTPGPGPGPAPCPTPAP*G )-3')	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C [auth A], D [auth B]	IPR011598	Myc-type, basic helix-loop-helix (bHLH) domain	Domain
C [auth A], D [auth B]	IPR036638	Helix-loop-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. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.