Genetic characterisation of the cjaAB operon of Campylobacter coli.
We investigated the regulation of the cjaA and cjaB genes of Campylobacter coli. These genes are seemingly arranged into one operon but appear to encode functionally different proteins i.e. an extracytoplasmic solute receptor and a MHS - metabolite: H+ symporter transport protein. Analysis of various transcriptional cjaA and/or cjaB lacZ fusion constructs revealed that both genes are arranged in an operon. RACE analysis located the transcription start site of the cjaAB operon 46 bp upstream of the translation start point. Beta-galactosidase reporter assays yielded much higher activity for the cjaA than the cjaB gene fusion products. RT-PCR showed unequal amounts of mRNA, indicating differential post-transcriptional processing of cjaA and cjaB mRNA possibly related to the presence of inverted repeats in the intergenic region. Phylogenetic analysis grouped CjaB into a new MHS sub-family together with potential transporters with uncharacterised functions of Campylobacter and Helicobacter. Notably, no CjaB family members were identified in epsilon-Proteobacteria from different ecological niches, such as H. hepaticus and Wolinella succinogenes.
Wyszyńska
Agnieszka
A
Department of Bacterial Genetics, Institute of Microbiology, Warsaw University, 02-096 Warsaw, Miecznikowa 1, Poland.
Pawłowski
Marcin
M
Bujnicki
Janusz
J
Pawelec
Dariusz
D
Van Putten
Jos P M
JP
Brzuszkiewicz
Elzbieta
E
Jagusztyn-Krynicka
Elzbieta K
EK
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D017000:Campylobacter coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics; D010802:Phylogeny
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins