Chemotaxis proteins and transducers for aerotaxis in Pseudomonas aeruginosa.
It was previously shown that the chemotaxis gene cluster 1 (cheYZABW) was required for chemotaxis. In this study, the involvement of the same cluster in aerotaxis is described and two transducer genes for aerotaxis are identified. Aerotaxis assays of a number of deletion-insertion mutants of Pseudomonas aeruginosa PAO1 revealed that the chemotaxis gene cluster 1 and cheR are required for aerotaxis. Mutant strains which contained deletions in the methyl-accepting chemotaxis protein-like genes tlpC and tlpG showed decreased aerotaxis. A double mutant deficient in tlpC and tlpG was negative for aerotaxis. TlpC has 45% amino acid identity with the Escherichia coli aerotactic transducer Aer. The TlpG protein has a predicted C-terminal segment with 89% identity to the highly conserved domain of the E. coli serine chemoreceptor Tsr. A hydropathy plot of TlpG indicated that hydrophobic membrane-spanning regions are missing in TlpG. A PAS motif was found in the N-terminal domains of TlpC and TlpG. On this basis, the tlpC and tlpG genes were renamed aer and aer-2, respectively. No significant homology other than the PAS motif was detected in the N-terminal domains between Aer and Aer-2.
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan.
Chang Soo
CS
Hong
Maiko
M
Shitashiro
Akio
A
Kuroda
Tsukasa
T
Ikeda
Noboru
N
Takiguchi
Hisao
H
Ohtake
Junichi
J
Kato
D001426:Bacterial Proteins / Q000235:genetics*; D002633:Chemotaxis / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics; D016296:Mutagenesis; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics
D001426:Bacterial Proteins; D008565:Membrane Proteins; C089936:TlpC protein, Bacillus subtilis