title: Motility and chemotaxis in alkaliphilic Bacillus species.
abstract: Alkaliphilic Bacillus species grow at pH values up to approximately 11. Motile alkaliphilic Bacillus use electrochemical gradients of Na(+) (sodium-motive force) to power ion-coupled, flagella-mediated motility as opposed to the electrochemical gradients of H(+) (proton-motive force) used by most neutralophilic bacteria. Membrane-embedded stators of bacterial flagella contain ion channels through which either H(+) or Na(+) flow to energize flagellar rotation. Stators of the major H(+)-coupled type, MotAB, are distinguishable from Na(+)-coupled stators, PomAB of marine bacteria and MotPS of alkaliphilic Bacillus. Dual ion-coupling capacity is found in neutralophilic Bacillus strains with both MotAB and MotPS. There is also a MotAB variant that uses both coupling ions, switching as a function of pH. Chemotaxis of alkaliphilic Bacillus depends upon flagellar motility but also requires a distinct voltage-gated NaChBac-type channel. The two alkaliphile Na(+) channels provide new vistas on the diverse adaptations of sensory responses in bacteria.
authors.affiliation: NITE Bioresource Information Center, Department of Biotechnology, National Institute of Technology and Evaluation, Nishihara, Shibuya-ku, Tokyo, Japan. fujinami-shun@nite.go.jp
authors.forename: Shun
authors.initials: S
authors.lastname: Fujinami
authors.forename: Naoya
authors.initials: N
authors.lastname: Terahara
authors.forename: Terry Ann
authors.initials: TA
authors.lastname: Krulwich
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ito
mesh_terms: D001407:Bacillus / Q000502:physiology*; D027682:Cation Transport Proteins / Q000378:metabolism; D002633:Chemotaxis; D005407:Flagella / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D020409:Molecular Motor Proteins / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
chemical_list: D027682:Cation Transport Proteins; D020409:Molecular Motor Proteins; D012964:Sodium