Mutational and transcriptional analysis of the Campylobacter jejuni flagellar biosynthesis gene flhB.
A Campylobacter jejuni gene encoding a homologue of the flagellar biosynthesis gene flhB was identified downstream of the peroxide stress defence gene ahpC. Insertional mutagenesis of the flhB gene rendered C. jejuni non-motile, with most cells aflagellate, although a small number expressed truncated flagella. The absence of FlhB also appeared to affect cell shape, as the majority of cells were straight rather than curved rods. Transcription of the flagellin gene flaA was significantly reduced in the C. jejuni flhB mutants, which also did not express significant amounts of flagellin proteins, indicating that FlhB is an essential protein for subsequent expression of flagellar genes. The transcription start site of the flhB gene, as determined by primer extension, was located 91 bp upstream of the flhB start codon, but no recognizable promoter sequence could be identified immediately upstream of this transcription start site. Transcriptional flhB::lacZ reporter gene fusions confirmed that the flhB gene has its own promoter region, is expressed at very low levels and is transcribed independently of ahpC, and that its transcription is not regulated by iron or growth phase.
Matz
Claudia
C
School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK1.
van Vliet
Arnoud H M
AHM
Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK3.|Department of Gastroenterology and Hepatology, Academic Hospital Dijkzigt, Dr Molewaterplein 40, 3015 GD Rotterdam, The Netherlands2.
Ketley
Julian M
JM
Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK3.
Penn
Charles W
CW
School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK1.
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D016123:Campylobacter jejuni / Q000235:genetics* / Q000254:growth & development / Q000502:physiology / Q000648:ultrastructure; D005407:Flagella / Q000235:genetics*; D005408:Flagellin / Q000096:biosynthesis / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D017930:Genes, Reporter; D016680:Genome, Bacterial; D008565:Membrane Proteins; D009068:Movement; D009154:Mutation / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics*
D001426:Bacterial Proteins; C085668:FlhB protein, Bacteria; D008565:Membrane Proteins; C064779:MotB protein, Bacteria; D005408:Flagellin; C067138:flaA protein, bacteria