title: A novel type bacterial flagellar motor that can use divalent cations as a coupling ion.
abstract: The bacterial flagellar motor is a sophisticated nanomachine embedded in the cell envelope and powered by an electrochemical gradient of H(+), Na(+), or K(+)across the cytoplasmic membrane. Here we describe a new member of the bacterial flagellar stator channel family (MotAB1 of Paenibacillus sp. TCA20 (TCA-MotAB1)) that is coupled to divalent cations (Ca(2+)and Mg(2+)). In the absence of divalent cations of alkaline earth metals, no swimming was observed in Paenibacillus sp. TCA20, which grows optimally in Ca(2+)-rich environments. This pattern was confirmed by swimming assays of a stator-free Bacillus subtilis mutant expressing TCA-MotAB1. Both a stator-free and major Mg(2+)uptake system-deleted B. subtilis mutant expressing TCA-MotAB1 complemented both growth and motility deficiency under low Mg(2+)conditions and exhibited [Mg(2+)]in identical to that of the wild-type. This is the first report of a flagellar motor that can use Ca(2+)and Mg(2+)as coupling ions. These findings will promote the understanding of the operating principles of flagellar motors and molecular mechanisms of ion selectivity.
authors.affiliation: Graduate School of Life Sciences Toyo University, Oura-gun, Gunma 374-0193, Japan.
authors.forename: Riku
authors.initials: R
authors.lastname: Imazawa
authors.affiliation: Graduate School of Life Sciences Toyo University, Oura-gun, Gunma 374-0193, Japan.|Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Faculty of Life Sciences, Toyo University, Oura-gun, Gunma 374-0193, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Aoki
authors.affiliation: Graduate School of Life Sciences Toyo University, Oura-gun, Gunma 374-0193, Japan.
authors.forename: Motohiko
authors.initials: M
authors.lastname: Sano
authors.affiliation: Graduate School of Life Sciences Toyo University, Oura-gun, Gunma 374-0193, Japan.|Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585, Japan.|Faculty of Life Sciences, Toyo University, Oura-gun, Gunma 374-0193, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ito
mesh_terms: D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology*; D002414:Cations, Monovalent / Q000494:pharmacology; D005407:Flagella / Q000187:drug effects / Q000378:metabolism*; D042541:Intracellular Space / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000378:metabolism*; D009068:Movement / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D056507:Paenibacillus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D010802:Phylogeny; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002413:Cations, Divalent; D002414:Cations, Monovalent; D020409:Molecular Motor Proteins; D021122:Protein Subunits; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000584:Amiloride; D008274:Magnesium; C039614:ethylisopropylamiloride