title: Identification of the pac promoter from Kluyvera citrophila.
abstract: The nucleotide sequence of the 5'-terminal region of the pac gene encoding the penicillin G acylase from Kluyvera citrophila ATCC 21285 has been determined. The transcriptional start site has been identified by primer extension analysis in a different position to that previously found for the homologous pac gene of Escherichia coli W ATCC 11105. Two nucleotide changes in the -35 box appear to be responsible of the promoter displacement in K. citrophila. A putative upstream promoter element (A+T-rich enhancer sequence) and a binding site for the cAMP receptor protein (CRP) were located upstream of the -35 box. Transcriptional lacZ and cat fusions demonstrated that pac expression was subjected to catabolite repression mediated by cAMP and its receptor protein. Remarkably, phenylacetic acid which is a potent inducer of the penicillin G acylase from E. coli, was only able to cause a significant induction of the pac expression in CRP+ cells cultured in the presence of glucose, suggesting that this effect is CRP-dependent.
authors.affiliation: Department of Molecular Microbiology, Consejo Superior de Investigaciones Cientificas, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Roa
authors.forename: J L
authors.initials: JL
authors.lastname: García
mesh_terms: D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase; D004755:Enterobacteriaceae / Q000201:enzymology / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D007763:Lac Operon; D008969:Molecular Sequence Data; D010399:Penicillin Amidase / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic
chemical_list: D011993:Recombinant Fusion Proteins; D015500:Chloramphenicol O-Acetyltransferase; D010399:Penicillin Amidase