The Helix Rearrangement in the Periplasmic Domain of the Flagellar Stator B Subunit Activates Peptidoglycan Binding and Ion Influx.

The stator of the bacterial flagellar motor couples ion flow with torque generation. The ion-conducting stator channel opens only when incorporated into and anchored around the rotor via the peptidoglycan (PG) binding domain of the B subunit (MotB). However, no direct evidence of PG binding coupled with channel activation has been presented.