Bacterial sheathed flagella and the rotary motor model for the mechanism of bacterial motility

Abstract

The occurrence of bacterial flagella sheathed with an extension of the Gram-negative outer cell wall membrane poses problems for universal application of the rotary motor model for the bacterial flagellum mechanism. Two mechanisms are proposed which attempt to reconcile the existence of sheathed flagella with the rotary motor model, one of which involves rotation of both flagellar sheath and core, the other of which involves rotation of the core only, within a flexible wave-propagating sheath.