Bacterial flagellar motor.
The bacterial flagellar motor is a reversible rotary nano-machine, about 45 nm in diameter, embedded in the bacterial cell envelope. It is powered by the flux of H+ or Na+ ions across the cytoplasmic membrane driven by an electrochemical gradient, the proton-motive force or the sodium-motive force. Each motor rotates a helical filament at several hundreds of revolutions per second (hertz). In many species, the motor switches direction stochastically, with the switching rates controlled by a network of sensory and signalling proteins. The bacterial flagellar motor was confirmed as a rotary motor in the early 1970s, the first direct observation of the function of a single molecular motor. However, because of the large size and complexity of the motor, much remains to be discovered, in particular, the structural details of the torque-generating mechanism. This review outlines what has been learned about the structure and function of the motor using a combination of genetics, single-molecule and biophysical techniques, with a focus on recent results and single-molecule techniques.
Sowa
Yoshiyuki
Y
Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK.
Berry
Richard M
RM
D001419:Bacteria / Q000378:metabolism*; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000502:physiology*; D001703:Biophysics / Q000379:methods*; D005407:Flagella / Q000502:physiology*; D008954:Models, Biological; D008958:Models, Molecular; D008968:Molecular Conformation; D020409:Molecular Motor Proteins / Q000502:physiology*; D015398:Signal Transduction; D019415:Torque
D001426:Bacterial Proteins; D020409:Molecular Motor Proteins