National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)
R01AI132818
米国
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)
R01AI087946
米国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2020 タイトル: Molecular mechanism for rotational switching of the bacterial flagellar motor. 著者: Yunjie Chang / Kai Zhang / Brittany L Carroll / Xiaowei Zhao / Nyles W Charon / Steven J Norris / Md A Motaleb / Chunhao Li / Jun Liu / 要旨: The bacterial flagellar motor can rotate in counterclockwise (CCW) or clockwise (CW) senses, and transitions are controlled by the phosphorylated form of the response regulator CheY (CheY-P). To ...The bacterial flagellar motor can rotate in counterclockwise (CCW) or clockwise (CW) senses, and transitions are controlled by the phosphorylated form of the response regulator CheY (CheY-P). To dissect the mechanism underlying flagellar rotational switching, we use Borrelia burgdorferi as a model system to determine high-resolution in situ motor structures in cheX and cheY3 mutants, in which motors are locked in either CCW or CW rotation. The structures showed that CheY3-P interacts directly with a switch protein, FliM, inducing a major remodeling of another switch protein, FliG2, and altering its interaction with the torque generator. Our findings lead to a model in which the torque generator rotates in response to an inward flow of H driven by the proton motive force, and conformational changes in FliG2 driven by CheY3-P allow the switch complex to interact with opposite sides of the rotating torque generator, facilitating rotational switching.