Open AccessMotile ghosts of the halophilic archaeon, Haloferax volcanii
Author(s) -
Yoshiaki Kinosita,
Naohiko Mikami,
Zhengqun Li,
F. N. Braun,
Tessa E. F. Quax,
Chris van der Does,
Robert Ishmukhametov,
SonjaVerena Albers,
Richard M. Berry
Publication year - 2020
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2009814117
Subject(s) - haloferax volcanii , halophile , archaea , flagellum , dynein , molecular motor , biology , adenosine triphosphate , molecular machine , motor protein , kinesin , cooperativity , biochemistry , biophysics , bacteria , microbiology and biotechnology , microtubule , genetics , gene
Archaea swim using the archaellum (archaeal flagellum), a reversible rotary motor consisting of a torque-generating motor and a helical filament, which acts as a propeller. Unlike the bacterial flagellar motor (BFM), ATP (adenosine-5'-triphosphate) hydrolysis probably drives both motor rotation and filamentous assembly in the archaellum. However, direct evidence is still lacking due to the lack of a versatile model system. Here, we present a membrane-permeabilized ghost system that enables the manipulation of intracellular contents, analogous to the triton model in eukaryotic flagella and gliding Mycoplasma We observed high nucleotide selectivity for ATP driving motor rotation, negative cooperativity in ATP hydrolysis, and the energetic requirement for at least 12 ATP molecules to be hydrolyzed per revolution of the motor. The response regulator CheY increased motor switching from counterclockwise (CCW) to clockwise (CW) rotation. Finally, we constructed the torque-speed curve at various [ATP]s and discuss rotary models in which the archaellum has characteristics of both the BFM and F 1 -ATPase. Because archaea share similar cell division and chemotaxis machinery with other domains of life, our ghost model will be an important tool for the exploration of the universality, diversity, and evolution of biomolecular machinery.