title: A nonswarming mutant of Proteus mirabilis lacks the Lrp global transcriptional regulator.
abstract: Proteus swarming is the rapid cyclical population migration across surfaces by elongated cells that hyperexpress flagellar and virulence genes. The mini-Tn5 transposon mutant mns2 was isolated as a tight nonswarming mutant that did not elongate or upregulate flagellar and hemolysin genes. Individual cell motility was retained but was reduced. The transposon had inserted in the gene encoding the global transcriptional regulator Lrp (leucine-responsive regulatory protein), expression of which was upregulated in differentiating swarm cells. Swarming was restored to the lrp mutant by artificial overexpression of the flhDC flagellar regulatory master operon. Lrp may be a key component in generating or relaying signals that are required for flagellation and swarming, possibly acting through the flhDC operon.
authors.affiliation: Department of Pathology, University of Cambridge, United Kingdom.
authors.forename: N A
authors.initials: NA
authors.lastname: Hay
authors.forename: D J
authors.initials: DJ
authors.lastname: Tipper
authors.forename: D
authors.initials: D
authors.lastname: Gygi
authors.forename: C
authors.initials: C
authors.lastname: Hughes
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins / Q000235:genetics*; D029968:Escherichia coli Proteins; D005407:Flagella / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D006460:Hemolysin Proteins / Q000235:genetics; D007930:Leucine; D051756:Leucine-Responsive Regulatory Protein; D008969:Molecular Sequence Data; D009154:Mutation; D011513:Proteus mirabilis / Q000235:genetics* / Q000502:physiology; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C090552:flhC protein, E coli; C090553:flhD protein, E coli; D051756:Leucine-Responsive Regulatory Protein; D007930:Leucine