title: Regulation of Escherichia coli pyrC by the purine regulon repressor protein.
abstract: The purine regulon repressor, PurR, was identified as a component of the Escherichia coli regulatory system for pyrC, the gene that encodes dihydroorotase, an enzyme in de novo pyrimidine nucleotide synthesis. PurR binds to a pyrC control site that resembles a pur regulon operator and represses expression by twofold. Mutations that increase binding of PurR to the control site in vitro concomitantly increase in vivo regulation. There are completely independent mechanisms for regulation of pyrC by purine and pyrimidine nucleotides. Cross pathway regulation of pyrC by PurR may provide one mechanism to coordinate synthesis of purine and pyrimidine nucleotides.
authors.affiliation: Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907.
authors.forename: K Y
authors.initials: KY
authors.lastname: Choi
authors.forename: H
authors.initials: H
authors.lastname: Zalkin
mesh_terms: D000581:Amidohydrolases / Q000235:genetics*; D004080:Dihydroorotase / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005809:Genes, Regulator; D006160:Guanosine Triphosphate / Q000378:metabolism; D009154:Mutation; D011687:Purines / Q000494:pharmacology*; D011742:Pyrimidine Nucleotides / Q000096:biosynthesis*; D012097:Repressor Proteins / Q000494:pharmacology*; D014157:Transcription Factors / Q000494:pharmacology*
chemical_list: D011687:Purines; D011742:Pyrimidine Nucleotides; D012097:Repressor Proteins; D014157:Transcription Factors; D006160:Guanosine Triphosphate; D000581:Amidohydrolases; D004080:Dihydroorotase