Temperature-dependent regulation of Yersinia enterocolitica Class III flagellar genes.
Temperature is a key environmental cue for Yersinia enterocolitica as well as for the two other closely related pathogens, Yersinia pestis and Yersinia pseudotuberculosis. Between the range of 30 degrees C and 37 degrees C, Y. enterocolitica phase-varies between motility and plasmid-encoded virulence gene expression. To determine how temperature regulates Y. enterocolitica motility, we have been dissecting the flagellar regulatory hierarchy to determine at which level motility is blocked by elevated temperature (37 degrees C). Here we report the cloning, DNA sequences, and regulation of the two main regulators of Class III flagellar genes, fliA (sigma F) and flgM (anti-sigma F), and a third gene, flgN, which we show is required for filament assembly. Identification of the Y. enterocolitica fliA and flgM genes was accomplished by functional complementation of both S. typhimurium and Y. enterocolitica mutations and by DNA sequence analysis. The Y. enterocolitica fliA gene, encoding the flagellar-specific sigma-factor, sigma F, maps immediately downstream of the three flagellin structural genes. The flgM and flgN genes, encoding anti-sigma F and a gene product required for filament assembly, respectively, map downstream of the invasin (inv) gene but are transcribed in the opposite (convergent) direction. By using Northern blot analyses we show that transcription of both fliA and flgM is immediately arrested when cells are exposed to 37 degrees C, coincident with the timing of virulence gene induction. Unlike S. typhimurium flgM mutants, Y. enterocolitica flgM mutants are fully virulent.
Kapatral
V
V
Department of Microbiology, Molecular Biology, and Biochemistry, University of Idaho, Moscow 83843, USA.
Olson
J W
JW
Pepe
J C
JC
Miller
V L
VL
Minnich
S A
SA
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D005407:Flagella / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D010641:Phenotype; D012329:RNA, Bacterial; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000235:genetics*; D013696:Temperature; D015533:Transcriptional Activation; D014774:Virulence / Q000235:genetics; D015008:Yersinia enterocolitica / Q000235:genetics* / Q000472:pathogenicity / Q000648:ultrastructure
D001426:Bacterial Proteins; D004269:DNA, Bacterial; C087498:FlgN protein, Bacteria; C064971:FliA protein, Bacteria; D012329:RNA, Bacterial; D012808:Sigma Factor; C071266:FlgM protein, Bacteria