Rotational direction of flagellar motor from the conformation of FliG middle domain in marine Vibrio

Nishikino, Tatsuro; Hijikata, Atsushi; Miyanoiri, Yohei; Onoue, Yasuhiro; Kojima, Seiji; Shirai, Tomoyuki; Homma, Michio

doi:10.1038/s41598-018-35902-6

Cited by 24 publications

(32 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is possible that high electrorotation speed temporarily forced the rotor complex into a clockwise conformation. Physical (24,25) and genetic (26) changes in the rotor complex can affect switching with or without CheY. In wild-type cells, clockwise bias is reduced under low loads (27) and during stator remodeling from low to high stator unit number (14), making our observation of occasional clockwise switch at low stator unit number even more surprising.…”

Section: Discussionmentioning

confidence: 83%

Torque-dependent remodeling of the bacterial flagellar motor

Wadhwa

Phillips

Berg

2019

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Multisubunit protein complexes are ubiquitous in biology and perform a plethora of essential functions. Most of the scientific literature treats such assemblies as static: their function is assumed to be independent of their manner of assembly, and their structure is assumed to remain intact until they are degraded. Recent observations of the bacterial flagellar motor, among others, bring these notions into question. The torque-generating stator units of the motor assemble and disassemble in response to changes in load. Here, we used electrorotation to drive tethered cells forward, which decreases motor load, and measured the resulting stator dynamics. No disassembly occurred while the torque remained high, but all of the stator units were released when the motor was spun near the zero-torque speed. When the electrorotation was turned off, so that the load was again high, stator units were recruited, increasing motor speed in a stepwise fashion. A model in which speed affects the binding rate and torque affects the free energy of bound stator units captures the observed torque-dependent stator assembly dynamics, providing a quantitative framework for the environmentally regulated self-assembly of a major macromolecular machine. regulated self-assembly | bacterial flagellar motor | multisubunit complex | molecular motor

show abstract

Section: Discussionmentioning

confidence: 83%

Torque-dependent remodeling of the bacterial flagellar motor

Wadhwa

Phillips

Berg

2019

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The dramatic conformational changes in FliG2 are accommodated by the flexibility of the helical linker between the FliG2 MC domains 31-33 . This helix contains a highly conserved Gly-Gly residue pair located near the C-terminus of the helix 32,34,35 . The large rearrangement of FliG2 during directional switching allows it to engage different parts of the stator complex in the CW and CCW conformations.…”

Section: Discussionmentioning

confidence: 99%

Molecular Mechanism for Rotational Switching of the Bacterial Flagellar Motor

Chang

Zhang

Carroll

et al. 2020

Preprint

View full text Add to dashboard Cite

23The bacterial flagellar motor is a remarkable nanomachine that can rapidly rotate in both 24 counter-clockwise (CCW) and clockwise (CW) senses. The transitions between CCW and CW 25 rotation are critical for chemotaxis, and they are controlled by a signaling protein (CheY-P) 26 that interacts with a switch complex at the cytoplasmic side of the flagellar motor. However, 27 the exact molecular mechanism by which CheY-P controls the motor rotational switch remains 28 enigmatic. Here, we use the Lyme disease spirochete, Borrelia burgdorferi, as the model 29 system to dissect the mechanism underlying flagellar rotational switching. We first determined 30 high resolution in situ motor structures in the cheX and cheY3 mutants in which motors are 31 genetically locked in CCW or CW rotation. The structures showed that the CheY3 protein of 32 B. burgdorferi interacts directly with the FliM protein of the switch complex in a 33 phosphorylation-dependent manner. The binding of CheY3-P to FliM induces a major 34 remodeling of the switch protein FliG2 that alters its interaction with the torque generator. 35Because the remodeling of FliG2 is directly correlated with the rotational direction, our data 36 lead to a model for flagellar function in which the torque generator rotates in response to an 37 inward flow of H + driven by the proton motive force. Rapid conformational changes of FliG2 38 allow the switch complex to interact with opposite sides of the rotating torque generator, 39 thereby facilitating rotational switching between CW and CCW. 40 assembling the collar, stator complexes, and C-ring together, we revealed a complex 130 architecture of the CW-rotating flagellar motor with unprecedented details (Fig. 1h, i). 131 132 CheY3-P binds to the FliM protein of the C-ring 133The well-defined C-ring in the ∆cheX mutant was found to be associated with two previously 134 unidentified densities (arrowheads indicated in Fig. 1d, e). We hypothesized that these 135 densities represent bound CheY3-P, as high levels of CheY3-P are expected in the ∆cheX 136 cells 14 . To characterize CheY3-P and its interaction with the ∆cheX motor, we replaced the 137 cheX-cheY3 genes with cheY3-gfp, generating a cheX::cheY3-GFP mutant (Extended Data Fig. 138

show abstract

“…A hinge connecting FliG CN and FliG CC has a highly flexible nature at the conserved MFXF motif, allowing FliG CC to rotate 180° relative to FliG CN to reorient Arg-281 and Asp-289 residues in Helix Torque to achieve a symmetric elementary process of torque generation in both CCW and CW rotation ( Fig. 3 B) [ [53] , [54] , [55] , [56] ]. Structural comparisons between Tm-FliG MC of the wild-type and Tm-FliG MC with the CW-locked deletion have shown that the CW-locked deletion induces a 90° rotation of FliG CC relative to FliG CN through the MFXF motif ( Fig.…”

Section: Structural Basis For the Rotational Switching Mechanismmentioning

confidence: 99%

Directional Switching Mechanism of the Bacterial Flagellar Motor

Minamino

Kinoshita

Namba

2019

Computational and Structural Biotechnology Journal

View full text Add to dashboard Cite

Bacteria sense temporal changes in extracellular stimuli via sensory signal transducers and move by rotating flagella towards into a favorable environment for their survival. Each flagellum is a supramolecular motility machine consisting of a bi-directional rotary motor, a universal joint and a helical propeller. The signal transducers transmit environmental signals to the flagellar motor through a cytoplasmic chemotactic signaling pathway. The flagellar motor is composed of a rotor and multiple stator units, each of which acts as a transmembrane proton channel to conduct protons and exert force on the rotor. FliG, FliM and FliN form the C ring on the cytoplasmic face of the basal body MS ring made of the transmembrane protein FliF and act as the rotor. The C ring also serves as a switching device that enables the motor to spin in both counterclockwise (CCW) and clockwise (CW) directions. The phosphorylated form of the chemotactic signaling protein CheY binds to FliM and FliN to induce conformational changes of the C ring responsible for switching the direction of flagellar motor rotation from CCW to CW. In this mini-review, we will describe current understanding of the switching mechanism of the bacterial flagellar motor.

show abstract

Rotational direction of flagellar motor from the conformation of FliG middle domain in marine Vibrio

Cited by 24 publications

References 60 publications

Torque-dependent remodeling of the bacterial flagellar motor

Torque-dependent remodeling of the bacterial flagellar motor

Molecular Mechanism for Rotational Switching of the Bacterial Flagellar Motor

Directional Switching Mechanism of the Bacterial Flagellar Motor

Contact Info

Product

Resources

About