title: Regulation of Escherichia coli purA by purine repressor, one component of a dual control mechanism.
abstract: Escherichia coli purA encodes adenylosuccinate synthetase, one of two enzymes required for synthesis of AMP from IMP. purA is subject to two- to threefold regulation by purR and about twofold regulation by a purR-independent mechanism. The 5'-flanking region of purA confers purR-dependent transcriptional regulation of purA but not the purR-independent regulation. Two operator sites in the 5'-flanking region which bind purine repressor in vitro and are required for in vivo regulation were identified. The purR-independent regulation may be posttranscriptional. It is now established that all transcription units involved in de novo synthesis of purine nucleotides, nine pur operons, as well as purR itself and guaBA, are subject to purR control.
authors.affiliation: Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907.
authors.forename: B
authors.initials: B
authors.lastname: He
authors.forename: H
authors.initials: H
authors.lastname: Zalkin
mesh_terms: D000249:Adenosine Monophosphate / Q000096:biosynthesis; D000265:Adenylosuccinate Synthase / Q000235:genetics*; D001426:Bacterial Proteins / Q000494:pharmacology*; D001483:Base Sequence; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D007291:Inosine Monophosphate / Q000096:biosynthesis; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016297:Mutagenesis, Site-Directed; D009875:Operator Regions, Genetic / Q000235:genetics*; D012097:Repressor Proteins / Q000494:pharmacology*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C065825:PurR protein, Bacteria; C489317:PurR protein, E coli; D012097:Repressor Proteins; D007291:Inosine Monophosphate; D000249:Adenosine Monophosphate; D000265:Adenylosuccinate Synthase