Structure of the Lrp-regulated serA promoter of Escherichia coli K-12.
Expression of the Escherichia coli serA gene is activated in vivo by the product of the lrp gene, leucine-responsive regulatory protein (Lrp), an effect partially reversed by L-leucine. We show here that serA is transcribed from two promoters, P1 45 bp upstream of the translation start site, and P2 92 bp further upstream. Lrp binds to a long AT-rich sequence from -158 to -82 from the start of the coding region, i.e. upstream of P1 and overlapping P2. It activates transcription from P1 and represses expression from P2. A second regulator, cAMP/CRP, activates P2, an effect that is largely inhibited by Lrp, such that catabolite repressor protein (Crp) and Lrp are rival activators of serA transcription.
Yang
Li
L
Biology Department, Concordia University, Montreal, Quebec, Canada.
Lin
Rong Tuan
RT
Newman
Elaine B
EB
D001483:Base Sequence; D001665:Binding Sites; D002237:Carbohydrate Dehydrogenases / Q000235:genetics*; D002352:Carrier Proteins; D002876:Chromosomes, Bacterial; D000242:Cyclic AMP / Q000378:metabolism; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism; D018983:DNA Footprinting; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism*; D003850:Deoxyribonuclease I; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D007763:Lac Operon; D051756:Leucine-Responsive Regulatory Protein; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D050543:Phosphoglycerate Dehydrogenase; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics; D014157:Transcription Factors
D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C497278:Lrp protein, E coli; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D051756:Leucine-Responsive Regulatory Protein; D000242:Cyclic AMP; D002237:Carbohydrate Dehydrogenases; D050543:Phosphoglycerate Dehydrogenase; D003850:Deoxyribonuclease I