Bacteria, Rev Your Engines: Stator Dynamics Regulate Flagellar Motility

Many bacteria move through liquids and across surfaces by using flagella-filaments propelled by a membrane-embedded rotary motor. Much is known about the flagellum: its basic structure, the function of its individual motor components, and the regulation of its synthesis. However, we are only beginning to identify the dynamics of flagellar proteins and to understand how the motor structurally adapts to environmental stimuli. In this review, we discuss the external and cellular factors that influence the dynamics of stator complexes (the ion-conducting channels of the flagellar motor). We focus on recent discoveries suggesting that stator dynamics are a means for controlling flagellar function in response to different environments.