Mutational analysis of the GTP-binding motif of FlhF which regulates the number and placement of the polar flagellum in Vibrio alginolyticus.
Precise regulation of the number and placement of flagella is critical for the mono-flagellated bacterium Vibrio alginolyticus to swim efficiently. We previously proposed a model in which the putative GTPase FlhF determines the polar location and generation of the flagellum, the putative ATPase FlhG interacts with FlhF to prevent FlhF from localizing to the pole, and thus FlhG negatively regulates the flagellar number in V. alginolyticus cells. To investigate the role of the GTP-binding motif of FlhF, we generated a series of alanine-replacement mutations at the positions that are highly conserved among homologous proteins. The results indicate that there is a correlation between the polar localization and the ability to produce flagella in the mutants. We investigated whether the mutations in the GTP-binding motif affected the ability to interact with FlhG. In contrast to our prediction, no significant difference was detected in the interaction with FlhG between the wild-type and mutant FlhFs. We showed that the GTP-binding motif of FlhF is important for polar localization of the flagellum but not for the interaction with FlhG.
Kusumoto
Akiko
A
Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-Ku, Nagoya 464-8602, Japan.
Nishioka
Noriko
N
Kojima
Seiji
S
Homma
Michio
M
D000409:Alanine / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D016764:Cell Polarity; D004252:DNA Mutational Analysis; D005407:Flagella / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D047468:Immunoprecipitation; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D009068:Movement; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011485:Protein Binding; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D044149:Vibrio alginolyticus / Q000166:cytology* / Q000378:metabolism*
D001426:Bacterial Proteins; D050505:Mutant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C078317:flhF protein, Bacteria; D006160:Guanosine Triphosphate; D020559:Monomeric GTP-Binding Proteins; D000409:Alanine