title: An antisense transcript from within the ptsG promoter region in Escherichia coli.
abstract: The ptsG gene, encoding the major glucose uptake system in Escherichia coli, is expressed from 2 promoters, a minor promoter p2 and a major downstream promoter p1. Transcription from both promoters is repressed by Mlc, and expression of p1 is activated by the cAMP/catabolite activator protein complex. Expression from p1 is also regulated post-transcriptionally in response to sugar stress via an sRNA, SgrS, which results in translational inhibition and mRNA degradation. Here, we demonstrate an additional level of complexity to the transcriptional pattern surrounding ptsG. A third promoter, p3, located between p1 and p2, was found to express a transcript antisense to ptsG. This promoter was detected by in vitro transcription and by RNA polymerase footprinting techniques and in vivo by S1 analysis and fusions with a lacZ reporter gene. Although the intrinsic strength of the p3 promoter was comparable to that of ptsG, it proved difficult to identify a full-length transcript. A faint transcript of greater than 400 nt could be detected. The transcript thus has more of the characteristics of a divergently expressed cryptic unstable transcript (CUT) than a prokaryotic sRNA.
authors.affiliation: UPR9073-CNRS Institut de Biologie Physico-Chimique, Paris, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Pennetier
authors.forename: Jacques
authors.initials: J
authors.lastname: Oberto
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Plumbridge
mesh_terms: D001709:Biotechnology; D018983:DNA Footprinting; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D016372:RNA, Antisense / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase; D012321:DNA-Directed RNA Polymerases