Structural basis of bacterial flagellar motor rotation and switching

The bacterial flagellar motor, a remarkable rotary machine, can rapidly switch between counterclockwise (CCW) and clockwise (CW) rotational directions to control the migration behavior of the bacterial cell. The flagellar motor consists of a bidirectional spinning rotor surrounded by torque-generating stator units. Recent high-resolution in vitro and in situ structural studies have revealed stunning details of the individual components of the flagellar motor and their interactions in both the CCW and CW senses. In this review, we discuss these structures and their implications for understanding the molecular mechanisms underlying flagellar rotation and switching.

Automated summary

The bacterial flagellar motor is a rotary machine that can rapidly switch between counterclockwise and clockwise rotational directions to control bacterial cell migration behavior. Recent high-resolution structural studies have revealed detailed interactions of the components in both rotational senses, providing insight into the molecular mechanisms underlying flagellar rotation and switching.