The iron-induced ferredoxin FdxA of Campylobacter jejuni is involved in aerotolerance.
A gene encoding a putative 2[4Fe--4S] ferredoxin (FdxA) was identified upstream of, and divergent to the peroxide stress defense gene ahpC of the microaerophilic pathogen Campylobacter jejuni. The transcription start site of fdxA was located 27 and 28 bp upstream of the fdxA start codon. Transcriptional fusions of the fdxA promoter to a lacZ reporter gene demonstrated that expression of fdxA is iron-induced, and thus oppositely regulated to the iron-repressed ahpC gene. Insertional mutagenesis of the fdxA gene did not affect microaerobic growth of C. jejuni, but significantly reduced aerotolerance of C. jejuni. The fdxA gene is the first reported iron-induced gene of C. jejuni, and encodes a novel component of its oxidative stress defense.
Department of Genetics, University of Leicester, UK. avvliet@ision.nl
A H
AH
van Vliet
M A
MA
Baillon
C W
CW
Penn
J M
JM
Ketley
D000332:Aerobiosis; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D016123:Campylobacter jejuni / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005288:Ferredoxins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D017930:Genes, Reporter; D007501:Iron / Q000502:physiology*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D018384:Oxidative Stress; D010088:Oxidoreductases; D010455:Peptides / Q000235:genetics; D011993:Recombinant Fusion Proteins; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D005288:Ferredoxins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D007501:Iron; D010088:Oxidoreductases