Coupling ion specificity of chimeras between H(+)- and Na(+)-driven motor proteins, MotB and PomB, in Vibrio polar flagella

EMBO J. 2000 Jul 17;19(14):3639-48. doi: 10.1093/emboj/19.14.3639.

Abstract

We have shown that a hybrid motor consisting of proton-type Rhodobacter sphaeroides MotA and sodium-type VIBRIO: alginolyticus PomB, MotX and MotY, can work as a sodium-driven motor in VIBRIO: cells. In this study, we tried to substitute the B subunits, which contain a putative ion-binding site in the transmembrane region. Rhodobacter sphaeroides MotB did not work with either MotA or PomA in Vibrio cells. Therefore, we constructed chimeric proteins (MomB), which had N-terminal MotB and C-terminal PomB. MomB proteins, with the entire transmembrane region derived from the H(+)-type MotB, gave rise to an Na(+) motor with MotA. The other two MomB proteins, in which the junction sites were within the transmembrane region, also formed Na(+) motors with PomA, but were changed for Na(+) or Li(+) specificity. These results show that the channel part consisting of the transmembrane regions from the A and B subunits can interchange Na(+)- and H(+)-type subunits and this can affect the ion specificity. This is the first report to have changed the specificity of the coupling ions in a bacterial flagellar motor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Cations, Monovalent / metabolism
  • Cations, Monovalent / pharmacology
  • Flagella / drug effects
  • Flagella / metabolism*
  • Genotype
  • Hydrogen / metabolism
  • Hydrogen / pharmacology
  • Lithium / metabolism
  • Lithium / pharmacology
  • Locomotion / drug effects
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Molecular Motor Proteins / metabolism
  • Molecular Sequence Data
  • Mutation
  • Protons
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism*
  • Rhodobacter sphaeroides* / genetics
  • Sequence Alignment
  • Sodium / metabolism
  • Sodium / pharmacology
  • Sodium Channels / chemistry
  • Sodium Channels / genetics
  • Sodium Channels / metabolism*
  • Substrate Specificity
  • Vibrio / drug effects
  • Vibrio / genetics
  • Vibrio / metabolism*

Substances

  • Bacterial Proteins
  • Cations, Monovalent
  • Membrane Proteins
  • Molecular Motor Proteins
  • MotA protein, Bacteria
  • MotB protein, Bacteria
  • PomA protein, Vibrio
  • PomB protein, Vibrio
  • Protons
  • Recombinant Fusion Proteins
  • Sodium Channels
  • Hydrogen
  • Lithium
  • Sodium