Structural insights into the assembly mechanism of the molecular bushing in the bacterial flagellar motor
5 affiliations
- 1Graduate School of Frontier Biosciences, The University of Osaka, Suita, Osaka, Japan
- 2Present Address: Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
- 3Institute for Protein Research, The University of Osaka, Suita, Osaka, Japan
- 4The School of Biological Sciences, University of Utah, Salt Lake City, UT USA
- 5JEOL YOKOGUSHI Research Alliance Laboratories, The University of Osaka, Suita, Osaka, Japan
Abstract
The LP-ring complex of the Salmonella flagellar motor acts as a bushing that supports high-speed rotation of the rod, which serves as a drive shaft. The L-ring, P-ring, and distal rod consist of FlgH, FlgI, and FlgG, respectively. LP-ring formation begins with P-ring assembly around the distal rod, where it remains firmly attached until the L-ring assembles above it. L-ring formation induces P-ring detachment, allowing the rod to freely rotate within the LP-ring, but this mechanism remains unclear. Here, we report the cryoEM structure of the P-ring assembled on a polyrod, an unusually elongated rod structure. The P-ring exhibits a slightly elliptical shape with a 2.7° tilt relative to the rod axis for its stable attachment. However, L-ring assembly on the P-ring causes steric clashes with the rod to induce P-ring detachment, allowing it to adopt a circular shape and complete the LP-ring as a functional bushing.
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BibTeX
@article{yamaguchi2026structural,
title = {{Structural insights into the assembly mechanism of the molecular bushing in the bacterial flagellar motor}},
author = {Tomoko Yamaguchi and Tohru Minamino and Takayuki Kato and Fabienne F. V. Chevance and Kelly T. Hughes and Keiichi Namba},
journal = {Communications Biology},
year = {2026},
month = jul,
doi = {10.1038/s42003-026-10640-y},
url = {https://doi.org/10.1038/s42003-026-10640-y},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Structural insights into the assembly mechanism of the molecular bushing in the bacterial flagellar motor
AU - Tomoko Yamaguchi
AU - Tohru Minamino
AU - Takayuki Kato
AU - Fabienne F. V. Chevance
AU - Kelly T. Hughes
AU - Keiichi Namba
PY - 2026
DA - 2026/07/13
JO - Communications Biology
DO - 10.1038/s42003-026-10640-y
UR - https://doi.org/10.1038/s42003-026-10640-y
AB - The LP-ring complex of the Salmonella flagellar motor acts as a bushing that supports high-speed rotation of the rod, which serves as a drive shaft. The L-ring, P-ring, and distal rod consist of FlgH, FlgI, and FlgG, respectively. LP-ring formation begins with P-ring assembly around the distal rod, where it remains firmly attached until the L-ring assembles above it. L-ring formation induces P-ring detachment, allowing the rod to freely rotate within the LP-ring, but this mechanism remains unclear. Here, we report the cryoEM structure of the P-ring assembled on a polyrod, an unusually elongated rod structure. The P-ring exhibits a slightly elliptical shape with a 2.7° tilt relative to the rod axis for its stable attachment. However, L-ring assembly on the P-ring causes steric clashes with the rod to induce P-ring detachment, allowing it to adopt a circular shape and complete the LP-ring as a functional bushing.
SN - 2399-3642
ER -