title: Torque generation by the flagellar rotary motor.
abstract: A review is given of the structure and dynamics of the flagellar rotary motor. Force-generating elements in a motor driving a tethered bacterium (a cell fixed to the substratum by a single flagellum) exert forces of order 20 pN while moving at speeds of order 1 micron/s. Force-generating elements in a motor driving a flagellar filament in a bundle exert forces some 10-fold lower but move at speeds more than 10-fold higher. The motor torque-speed relationship has been measured over a wide dynamic range. Motors strongly resist being driven backwards and are easily broken.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Berg
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D055592:Biophysical Phenomena; D001703:Biophysics; D002465:Cell Movement / Q000502:physiology; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D005407:Flagella / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D008954:Models, Biological; D009154:Mutation; D011522:Protons; D012399:Rotation; D012486:Salmonella typhimurium / Q000737:chemistry / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D011522:Protons