title: Bacterial Flagellar Motor Switch in Response to CheY-P Regulation and Motor Structural Alterations.
abstract: The bacterial flagellar motor (BFM) is a molecular machine that rotates the helical filaments and propels the bacteria swimming toward favorable conditions. In our previous works, we built a stochastic conformational spread model to explain the dynamic and cooperative behavior of BFM switching. Here, we extended this model to test whether it can explain the latest experimental observations regarding CheY-P regulation and motor structural adaptivity. We show that our model predicts a strong correlation between rotational direction and the number of CheY-Ps bound to the switch complex, in agreement with the latest finding from Fukuoka et al. It also predicts that the switching sensitivity of the BFM can be fine-tuned by incorporating additional units into the switch complex, as recently demonstrated by Yuan et al., who showed that stoichiometry of FliM undergoes dynamic change to maintain ultrasensitivity in the motor switching response. In addition, by locking some rotor switching units on the switch complex into the stable clockwise-only conformation, our model has accurately simulated recent experiments expressing clockwise-locked FliG(ΔPAA) into the switch complex and reproduced the increased switching rate of the motor.
authors.affiliation: Biodynamic Optical Imaging Center, School of Life Science, Peking University, Beijing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Ma
authors.affiliation: Department of Frontier Bioscience, Hosei University, Tokyo, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Sowa
authors.affiliation: Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; School of Medical Science, EMBL Australia Node for Single Molecule Science, The University of New South Wales, Sydney, New South Wales, Australia. Electronic address: m.baker@victorchang.edu.au.
authors.forename: Matthew A B
authors.initials: MA
authors.lastname: Baker
authors.affiliation: Biodynamic Optical Imaging Center, School of Life Science, Peking University, Beijing, China. Electronic address: fbai@pku.edu.cn.
authors.forename: Fan
authors.initials: F
authors.lastname: Bai
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D005407:Flagella / Q000378:metabolism*; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D001426:Bacterial Proteins; D020409:Molecular Motor Proteins