A plausible mechanism for flagellar rotation in bacteria.

A novel model for the action of the flagellar motor of bacteria is presented in which rotational motion is produced by conformational changes in a helically or rotationally symmetric multi-subunit component of the basal body. The model is consistent with the known properties of the motor, including its ability to rotate equally well clockwise and counterclockwise. Formally, the model is similar to mechanisms that have been proposed for other biologic transducers of free energy, such as active transporters.