Annotations: 1QQA

Domain Annotation: SCOP/SCOPe Classification SCOP Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
B [auth A]	d1qqaa1	All alpha proteins	lambda repressor-like DNA-binding domains	lambda repressor-like DNA-binding domains	GalR/LacI-like bacterial regulator	Purine repressor (PurR), N-terminal domain	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
B [auth A]	d1qqaa2	Alpha and beta proteins (a/b)	Periplasmic binding protein-like I	Periplasmic binding protein-like I	L-arabinose binding protein-like	Purine repressor (PurR), 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)
B [auth A]	SCOP2B Superfamily	Type 1 solute binding protein-like	8033268	3000125	SCOP2B (2022-06-29)
B [auth A]	SCOP2B Superfamily	lambda C1 repressor DNA-binding domain-like	8037211	3000119	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)
B [auth A]	LacI	e1qqaA4	A: alpha arrays	X: HTH	H: HTH	T: tetra-helical, lambda repressor-like	F: LacI	ECOD (1.6)
B [auth A]	Peripla_BP_3	e1qqaA3	A: a/b three-layered sandwiches	X: Flavodoxin-like	H: Class I glutamine amidotransferase-like	T: Periplasmic binding protein-like I	F: Peripla_BP_3	ECOD (1.6)
B [auth A]	Peripla_BP_1_1st_1	e1qqaA5	A: a/b three-layered sandwiches	X: Flavodoxin-like	H: Class I glutamine amidotransferase-like	T: Periplasmic binding protein-like I	F: Peripla_BP_1_1st_1	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B [auth A]	1.10.260.40	Mainly Alpha	Orthogonal Bundle	434 Repressor (Amino-terminal Domain)	lambda repressor-like DNA-binding domains	CATH (4.3.0)
B [auth A]	3.40.50.2300	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Response regulator	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
B [auth A]	PF13377	Periplasmic binding protein-like domain (Peripla_BP_3)	Periplasmic binding protein-like domain	This domain is found in a variety of transcriptional regulatory proteins. It is related to bacterial periplasmic binding proteins, although this domain is unlikely to be found in the periplasm. This domain acts as a sensor binding small molecule liga ...	This domain is found in a variety of transcriptional regulatory proteins. It is related to bacterial periplasmic binding proteins, although this domain is unlikely to be found in the periplasm. This domain acts as a sensor binding small molecule ligands that the DNA-binding domain responds to. This domain recognises Sugars, sugar phosphates, sugar acids and purines (Matilla et. al., FEMS Microbiology Reviews, fuab043, 45, 2021, 1. https://doi.org/10.1093/femsre/fuab043).	Domain
B [auth A]	PF00356	Bacterial regulatory proteins, lacI family (LacI)	Bacterial regulatory proteins, lacI family	-	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A [auth M]	DNA (5'-D(TPAPCPGPCPAPAPGPCPGPCPTPTPGPCPGP*T)-3')	-	-	-
B [auth A]	PROTEIN (PURINE NUCLEOTIDE SYNTHESIS REPRESSOR)	identical protein binding protein binding binding protein homodimerization activity protein dimerization activity DNA binding sequence-specific DNA binding sequence-specific double-stranded DNA binding transcription cis-regulatory region binding double-stranded DNA binding organic cyclic compound binding nucleic acid binding transcription regulatory region nucleic acid binding nucleobase binding identical protein binding protein binding binding protein homodimerization activity protein dimerization activity DNA binding sequence-specific DNA binding sequence-specific double-stranded DNA binding transcription cis-regulatory region binding double-stranded DNA binding organic cyclic compound binding nucleic acid binding transcription regulatory region nucleic acid binding nucleobase binding guanine binding purine nucleobase binding heterocyclic compound binding small molecule binding transcription regulator activity DNA-binding transcription factor activity DNA-binding transcription repressor activity	regulation of cellular process negative regulation of biological process negative regulation of nitrogen compound metabolic process negative regulation of cellular metabolic process regulation of primary metabolic process negative regulation of RNA biosynthetic process nucleobase-containing compound metabolic process regulation of nitrogen compound metabolic process DNA-templated transcription regulation of RNA metabolic process heterocycle metabolic process organic substance biosynthetic 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 negative regulation of nitrogen compound metabolic process negative regulation of cellular metabolic process regulation of primary metabolic process negative regulation of RNA biosynthetic process nucleobase-containing compound metabolic process regulation of nitrogen compound metabolic process DNA-templated transcription regulation of RNA metabolic process heterocycle metabolic process organic substance biosynthetic process negative regulation of nucleobase-containing compound metabolic process regulation of nucleobase-containing compound metabolic process negative regulation of DNA-templated transcription regulation of biological process cellular metabolic process negative regulation of metabolic process cellular nitrogen compound metabolic process primary metabolic process regulation of cellular metabolic process negative regulation of cellular biosynthetic process organic cyclic compound metabolic process regulation of gene expression biosynthetic process aromatic compound biosynthetic process negative regulation of macromolecule biosynthetic process organic cyclic compound biosynthetic process metabolic process regulation of macromolecule biosynthetic process macromolecule metabolic process regulation of DNA-templated transcription regulation of metabolic process negative regulation of RNA metabolic process cellular biosynthetic process RNA metabolic process RNA biosynthetic process nucleic acid biosynthetic process organic substance metabolic process negative regulation of cellular process nitrogen compound metabolic process regulation of RNA biosynthetic process negative regulation of macromolecule metabolic process regulation of biosynthetic process biological regulation regulation of macromolecule metabolic process nucleobase-containing compound biosynthetic process heterocycle biosynthetic process gene expression macromolecule biosynthetic process nucleic acid metabolic process regulation of cellular biosynthetic process negative regulation of biosynthetic process cellular process cellular aromatic compound metabolic process nucleotide biosynthetic process organonitrogen compound biosynthetic process cellular nitrogen compound biosynthetic process purine nucleotide metabolic process nucleobase-containing small molecule metabolic process purine-containing compound biosynthetic process phosphate-containing compound metabolic process small molecule metabolic process phosphorus metabolic process nucleoside phosphate metabolic process organonitrogen compound metabolic process nucleotide metabolic process purine-containing compound metabolic process organophosphate metabolic process organophosphate biosynthetic process nucleoside phosphate biosynthetic process purine nucleotide biosynthetic process negative regulation of small molecule metabolic process regulation of nucleotide biosynthetic process negative regulation of nucleotide metabolic process regulation of small molecule metabolic process negative regulation of nucleotide biosynthetic process regulation of nucleotide metabolic process regulation of phosphate metabolic process regulation of purine nucleotide metabolic process regulation of phosphorus metabolic process negative regulation of purine nucleotide metabolic process negative regulation of phosphate metabolic process negative regulation of purine nucleotide biosynthetic process regulation of purine nucleotide biosynthetic process negative regulation of phosphorus metabolic process	intracellular anatomical structure cytoplasm cellular anatomical entity cytosol

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
B [auth A]	IPR046335	Transcriptional regulator LacI/GalR-like, sensor domain	Domain
B [auth A]	IPR028082	Periplasmic binding protein-like I	Homologous Superfamily
B [auth A]	IPR010982	Lambda repressor-like, DNA-binding domain superfamily	Homologous Superfamily
B [auth A]	IPR023588	Transcription regulator HTH, PurR	Family
B [auth A]	IPR000843	LacI-type HTH domain	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.