Open AccessChemotaxis proteins and transducers for aerotaxis in Pseudomonas aeruginosa
Author(s) -
Hong Chang Soo,
Shitashiro Maiko,
Kuroda Akio,
Ikeda Tsukasa,
Takiguchi Noboru,
Ohtake Hisao,
Kato Junichi
Publication year - 2004
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(04)00009-6
Subject(s) - chemotaxis , mutant , gene , escherichia coli , biology , amino acid , homology (biology) , biochemistry , chemistry , receptor
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.