title: Two flagellar stators and their roles in motility and virulence in Pseudomonas syringae pv. tabaci 6605.
abstract: The motor proteins around the flagellar basal body consist of two cytoplasmic membrane proteins, MotA and MotB, and function as a complex that acts as the stator to generate the torque that drives rotation. Genome analysis of several Pseudomonas syringae pathovars revealed that there are two sets of genes encoding motor proteins: motAB and motCD. Deduced amino acid sequences for MotA/B and MotC/D showed homologies to the H(+)-driven stator from Escherichia coli and Na(+)-driven stator from Vibrio alginolyticus, respectively. However, the swimming motility of P. syringae pv. tabaci (Pta) 6605 was inhibited by the protonophore carbonyl cyanide m-chlorophenylhydrazone but not by the sodium stator-specific inhibitor phenamil. To identify a gene encoding the stator protein required for motility, ∆motAB, ∆motCD, and ∆motABCD mutants were generated. The ∆motCD mutant had remarkably reduced and the ∆motABCD mutant completely abolished swimming motilities, whereas the ∆motAB mutant retained some degree of these abilities. The ∆motCD and ∆motABCD mutants did not produce N-acyl-homoserine lactones (AHLs), quorum-sensing molecules in this pathogen, and remarkably reduced the ability to cause disease in host tobacco leaves, as we previously observed in the ∆fliC mutant strain. These results strongly indicate that both stator pairs in Pta 6605 are proton-dependent and that MotCD is important for not only flagellar motility but also for production of AHLs and the ability to cause disease in host plants.
authors.affiliation: Graduate School of Natural Science and Technology, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.
authors.forename: Eiko
authors.initials: E
authors.lastname: Kanda
authors.forename: Takafumi
authors.initials: T
authors.lastname: Tatsuta
authors.forename: Tomoko
authors.initials: T
authors.lastname: Suzuki
authors.forename: Fumiko
authors.initials: F
authors.lastname: Taguchi
authors.forename: Kana
authors.initials: K
authors.lastname: Naito
authors.forename: Yoshishige
authors.initials: Y
authors.lastname: Inagaki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Toyoda
authors.forename: Tomonori
authors.initials: T
authors.lastname: Shiraishi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ichinose
mesh_terms: D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics*; D005407:Flagella / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D008854:Microscopy, Electron; D020409:Molecular Motor Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D044224:Pseudomonas syringae / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology / Q000648:ultrastructure; D014026:Nicotiana / Q000382:microbiology; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D020409:Molecular Motor Proteins