Attmannspacher, U. and Scharf, B. and Schmitt, R. (2005) Control of speed modulation (chemokinesis) in the unidirectional rotary motor of Sinorhizobium meliloti. MOLECULAR MICROBIOLOGY, 56 (3). pp. 708-718. ISSN 0950-382X,
Full text not available from this repository. (Request a copy)Abstract
Swimming cells of Sinorhizobium meliloti are driven by flagella that rotate only clockwise. They can modulate rotary speed (achieve chemokinesis) and reorient the swimming path by slowing flagellar rotation. The flagellar motor is energized by proton motive force, and torque is generated by electrostatic interactions at the rotor/stator (FliG/MotA-MotB) interface. Like the Escherichia coli flagellar motor that switches between counterclockwise and clockwise rotation, the S. meliloti rotary motor depends on electrostatic interactions between conserved charged residues, namely, Arg294 and Glu302 (FliG) and Arg90, Glu98 and Glu150 (MotA). Unlike in E. coli, however, Glu150 is essential for torque generation, whereas residues Arg90 and Glu98 are crucial for the chemotaxis-controlled variation of rotary speed. Substitutions of either Arg90 or Glu98 by charge-neutralizing residues or even by their smaller, charge-maintaining isologues, lysine and aspartate, resulted in top-speed flagellar rotation and decreased potential to slow down in response to tactic signalling (chemokinesis-defective mutants). The data infer a novel mechanism of flagellar speed control by electrostatic forces acting at the rotor/stator interface. These features have been integrated into a working model of the speed-modulating rotary motor.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | BACTERIAL FLAGELLAR MOTOR; RHIZOBIUM-LUPINI H13-3; ROTOR PROTEIN FLIG; ESCHERICHIA-COLI; TORQUE GENERATION; CHEMOTAXIS; ROTATION; COMPLEX; MOTILITY; VECTORS; |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 14 May 2021 10:32 |
| Last Modified: | 14 May 2021 10:32 |
| URI: | https://pred.uni-regensburg.de/id/eprint/36197 |
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