@article{fd758ca5bc4f46e8b9c10a9b457a46e4,
title = "Multiple Conformations of the FliG C-Terminal Domain Provide Insight into Flagellar Motor Switching",
abstract = "Bacterial flagellar switching between counterclockwise and clockwise directions is mediated by the coupling of the chemotactic system and the motor switch complex. The conformational changes of FliG are closely associated with this switching mechanism. We present two crystal structures of FliG MC from Helicobacter pylori, each showing distinct domain orientations from previously solved structures. A 180° rotation of the charged ridge-containing C-terminal subdomain FliG Cα1-6 that is prompted by the rotational freedom of Met245 psi and Phe246 phi at the MFXF motif was revealed. Studies on the swarming and swimming behavior of Escherichia coli mutants further identified the importance of the 245MFXF 248 motif and a highly conserved residue, Asn216, in motor switching. Additionally, multiple conformations of FliG Cα1-6 were demonstrated by intramolecular cysteine crosslinking. The conformational flexibility of FliGc leads us to propose a model that accounts for the symmetrical torque generation process and for the dynamics of the motor.",
keywords = "bacterial protein, cysteine, flig protein, methionine, phenylalanine, unclassified drug",
author = "Lam, {Kwok Ho} and Ip, {Wing Sang} and Lam, {Yun Wah} and Chan, {Sun On} and Ling, {Thomas Kin Wah} and Au, {Shannon Wing Ngor}",
note = "Funding Information: We would like to thank David DeRosier and Dennis Thomas for the electron microscopy density map of the rotor, Daniela Stock and Lawrence Lee for the FliG ring model, and Jacky Ngo, David Blair, and Karen Ottemann for comments and feedback. We would also like to thank W.L. Chiang and Jean Kung for their technical help in the electron microscopic study and the staff at beamline BL17U at the Shanghai Synchrotron Radiation Facility, Shanghai, China, for their support. Additional thanks are due to the University Grants Council of the HKSAR One-Off Special Equipment Grant (SEG CUHK08) for the equipment used in this study. This study was supported by the Hong Kong Research Grants Council (CUHK4592/06M and CUHK460110) and a Direct Grant for Research from The Chinese University of Hong Kong (2030402 and 4440426). ",
year = "2012",
month = feb,
day = "8",
doi = "10.1016/j.str.2011.11.020",
language = "English",
volume = "20",
pages = "315--325",
journal = "Structure with Folding & design",
issn = "0969-2126",
publisher = "Cell Press",
number = "2",
}