Role of the MotB linker in the assembly and activation of the bacterial flagellar motor.
O'Neill, J., Xie, M., Hijnen, M., Roujeinikova, A.(2011) Acta Crystallogr D Biol Crystallogr 67: 1009-1016
- PubMed: 22120737 
- DOI: https://doi.org/10.1107/S0907444911041102
- Primary Citation of Related Structures:  
3S02, 3S03, 3S06, 3S0H, 3S0W, 3S0Y - PubMed Abstract: 
Bacterial flagella are driven by an ion influx through the peptidoglycan (PG)-tethered MotA/MotB stator. Stator precomplexes assemble in the membrane and remain inactive until they incorporate into the motor, upon which MotA/MotB changes conformation. The nature of this change and the mechanism of inhibition of the PG-binding and ion-conducting activities of the precomplexes are unknown. Here, the structural analysis of a series of N-terminally truncated MotB fragments is presented, the mechanism of inhibition by the linker is identified and the structural basis for the formation of the PG-binding-competent open-channel MotA/MotB conformation via a mechanism that entails linker unfolding and rotational displacement of MotB transmembrane helices is uncovered.
Organizational Affiliation: 
Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, England.