title: The Rhodobacter sphaeroides flagellar motor is a variable-speed rotor.
abstract: The rotation rate of the unidirectional stop/start motor of Rhodobacter sphaeroides was investigated using computerised motion analysis of tethered cells. The R. sphaeroides motor was found to have a variable rotation rate compared to the virtually constant-speed motor of wild-type and CheR mutant (smooth swimming) Escherichia coli. In addition, the dynamics of the R. sphaeroides motor during stopping was analysed with no consistent correlation behaviour. The motor could go from full rotation to stop, or stop to full rotation within one video frame, i.e. 0.02 s, but it could also slow down into a stop or restart slowly, taking up to 0.25 s. The R. sphaeroides motor under chemokinetic stimulation was also analysed and was found to show increased torque generation and reduced variation in rotation rate.
authors.affiliation: Department of Biochemistry, University of Oxford, UK.
authors.forename: H L
authors.initials: HL
authors.lastname: Packer
authors.forename: H
authors.initials: H
authors.lastname: Lawther
authors.forename: J P
authors.initials: JP
authors.lastname: Armitage
mesh_terms: D004926:Escherichia coli / Q000502:physiology; D005407:Flagella / Q000187:drug effects / Q000502:physiology*; D008124:Locomotion / Q000187:drug effects; D018892:Proton-Motive Force; D012242:Rhodobacter sphaeroides / Q000187:drug effects / Q000502:physiology*; D012399:Rotation; D019346:Sodium Acetate / Q000494:pharmacology
chemical_list: D019346:Sodium Acetate