title: Multiple Transcriptional Factors Regulate Transcription of the rpoE Gene in Escherichia coli under Different Growth Conditions and When the Lipopolysaccharide Biosynthesis Is Defective.
abstract: The RpoE σ factor is essential for the viability of Escherichia coli RpoE regulates extracytoplasmic functions including lipopolysaccharide (LPS) translocation and some of its non-stoichiometric modifications. Transcription of the rpoE gene is positively autoregulated by EσEand by unknown mechanisms that control the expression of its distally located promoter(s). Mapping of 5' ends of rpoE mRNA identified five new transcriptional initiation sites (P1 to P5) located distal to EσE-regulated promoter. These promoters are activated in response to unique signals. Of these P2, P3, and P4 defined major promoters, recognized by RpoN, RpoD, and RpoS σ factors, respectively. Isolation of trans-acting factors, in vitro transcriptional and gel retardation assays revealed that the RpoN-recognized P2 promoter is positively regulated by a QseE/F two-component system and NtrC activator, whereas the RpoD-regulated P3 promoter is positively regulated by a Rcs system in response to defects in LPS core biosynthesis, overproduction of certain lipoproteins, and the global regulator CRP. Strains synthesizing Kdo2-LA LPS caused up to 7-fold increase in the rpoEP3 activity, which was abrogated in Δ(waaC rcsB). Overexpression of a novel 73-nucleotide sRNA rirA (RfaH interacting RNA) generated by the processing of 5' UTR of the waaQ mRNA induces the rpoEP3 promoter activity concomitant with a decrease in LPS content and defects in the O-antigen incorporation. In the presence of RNA polymerase, RirA binds LPS regulator RfaH known to prevent premature transcriptional termination of waaQ and rfb operons. RirA in excess could titrate out RfaH causing LPS defects and the activation of rpoE transcription.
authors.affiliation: From the Unit of Bacterial Genetics, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland and.
authors.forename: Gracjana
authors.identifier: 0000-0001-8695-8065
authors.initials: G
authors.lastname: Klein
authors.affiliation: From the Unit of Bacterial Genetics, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland and.
authors.forename: Anna
authors.initials: A
authors.lastname: Stupak
authors.affiliation: From the Unit of Bacterial Genetics, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland and.
authors.forename: Daria
authors.initials: D
authors.lastname: Biernacka
authors.affiliation: From the Unit of Bacterial Genetics, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland and.
authors.forename: Pawel
authors.initials: P
authors.lastname: Wojtkiewicz
authors.affiliation: the Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, 23845 Borstel, Germany.
authors.forename: Buko
authors.initials: B
authors.lastname: Lindner
authors.affiliation: From the Unit of Bacterial Genetics, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland and satish.raina@pg.gda.pl.
authors.forename: Satish
authors.identifier: 0000-0003-3175-4932
authors.initials: S
authors.lastname: Raina
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008070:Lipopolysaccharides / Q000172:deficiency*; D011401:Promoter Regions, Genetic; D012808:Sigma Factor / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
chemical_list: D008070:Lipopolysaccharides; D012808:Sigma Factor; D014157:Transcription Factors; C063202:sporulation-specific sigma factors
keywords: LapB; RNA polymerase; RirA sRNA; RpoE; RpoS; bacterial transcription; glycosyltransferase; heptosyltransferase; lipopolysaccharide (LPS); transcription termination