The Flagellar Motor of Thermotoga maritima revealed by Cryo- Electron Tomography

2005 ◽  
Vol 2005 (Spring) ◽  
Author(s):  
Manuela Gruska ◽  
Ariane Briegel ◽  
Wolfgang Baumeister ◽  
J�rgen Plitzko
Keyword(s):  
Electron Tomography ◽  
Thermotoga Maritima ◽  
Flagellar Motor ◽  
Cryo Electron Tomography

scholarly journals Structural insights into flagellar stator–rotor interactions

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Yunjie Chang ◽  
Ki Hwan Moon ◽  
Xiaowei Zhao ◽  
Steven J Norris ◽  
MD A Motaleb ◽  
...  
Keyword(s):  
Conformational Change ◽  
High Speed ◽  
Electron Tomography ◽  
Deletion Mutants ◽  
Flagellar Motor ◽  
Wild Type ◽  
Cryo Electron Tomography ◽  
Flagellar Filament ◽  
Structural Insights

The bacterial flagellar motor is a molecular machine that can rotate the flagellar filament at high speed. The rotation is generated by the stator–rotor interaction, coupled with an ion flux through the torque-generating stator. Here we employed cryo-electron tomography to visualize the intact flagellar motor in the Lyme disease spirochete, Borrelia burgdorferi. By analyzing the motor structures of wild-type and stator-deletion mutants, we not only localized the stator complex in situ, but also revealed the stator–rotor interaction at an unprecedented detail. Importantly, the stator–rotor interaction induces a conformational change in the flagella C-ring. Given our observation that a non-motile mutant, in which proton flux is blocked, cannot generate the similar conformational change, we propose that the proton-driven torque is responsible for the conformational change required for flagellar rotation.

scholarly journals Intact Flagellar Motor of Borrelia burgdorferi Revealed by Cryo-Electron Tomography: Evidence for Stator Ring Curvature and Rotor/C-Ring Assembly Flexion

2009 ◽  
Vol 191 (16) ◽  
pp. 5026-5036 ◽  
Author(s):  
Jun Liu ◽  
Tao Lin ◽  
Douglas J. Botkin ◽  
Erin McCrum ◽  
Hanspeter Winkler ◽  
...  
Keyword(s):  
Borrelia Burgdorferi ◽  
Electron Tomography ◽  
Rotational Symmetry ◽  
Flagellar Motor ◽  
Cell Axis ◽  
Ring Assembly ◽  
Flagellar Motors ◽  
Cryo Electron Tomography ◽  
Flagellar Rotation

ABSTRACT The bacterial flagellar motor is a remarkable nanomachine that provides motility through flagellar rotation. Prior structural studies have revealed the stunning complexity of the purified rotor and C-ring assemblies from flagellar motors. In this study, we used high-throughput cryo-electron tomography and image analysis of intact Borrelia burgdorferi to produce a three-dimensional (3-D) model of the in situ flagellar motor without imposing rotational symmetry. Structural details of B. burgdorferi, including a layer of outer surface proteins, were clearly visible in the resulting 3-D reconstructions. By averaging the 3-D images of ∼1,280 flagellar motors, a ∼3.5-nm-resolution model of the stator and rotor structures was obtained. flgI transposon mutants lacked a torus-shaped structure attached to the flagellar rod, establishing the structural location of the spirochetal P ring. Treatment of intact organisms with the nonionic detergent NP-40 resulted in dissolution of the outermost portion of the motor structure and the C ring, providing insight into the in situ arrangement of the stator and rotor structures. Structural elements associated with the stator followed the curvature of the cytoplasmic membrane. The rotor and the C ring also exhibited angular flexion, resulting in a slight narrowing of both structures in the direction perpendicular to the cell axis. These results indicate an inherent flexibility in the rotor-stator interaction. The FliG switching and energizing component likely provides much of the flexibility needed to maintain the interaction between the curved stator and the relatively symmetrical rotor/C-ring assembly during flagellar rotation.

scholarly journals Intact Flagellar Motor Architecture Revealed by Cryo-Electron Tomography

2009 ◽  
Vol 96 (3) ◽  
pp. 412a
Author(s):  
Jun Liu ◽  
Tao Lin ◽  
Douglas J. Botkin ◽  
Erin McCrum ◽  
Hanspeter Winkler ◽  
...  
Keyword(s):  
Electron Tomography ◽  
Flagellar Motor ◽  
Cryo Electron Tomography

scholarly journals Bacterial flagellar motor PL-ring disassembly subcomplexes are widespread and ancient

2020 ◽  
Vol 117 (16) ◽  
pp. 8941-8947 ◽  
Author(s):  
Mohammed Kaplan ◽  
Michael J. Sweredoski ◽  
João P. G. L. M. Rodrigues ◽  
Elitza I. Tocheva ◽  
Yi-Wei Chang ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Electron Tomography ◽  
Complex Structures ◽  
Flagellar Motor ◽  
Additional Species ◽  
Bacterial Flagellum ◽  
Cryo Electron Tomography ◽  
Show Evidence ◽  
Bacterial Flagellar Motor ◽  
Horizontal Transfers

The bacterial flagellum is an amazing nanomachine. Understanding how such complex structures arose is crucial to our understanding of cellular evolution. We and others recently reported that in several Gammaproteobacterial species, a relic subcomplex comprising the decorated P and L rings persists in the outer membrane after flagellum disassembly. Imaging nine additional species with cryo-electron tomography, here, we show that this subcomplex persists after flagellum disassembly in other phyla as well. Bioinformatic analyses fail to show evidence of any recent horizontal transfers of the P- and L-ring genes, suggesting that this subcomplex and its persistence is an ancient and conserved feature of the flagellar motor. We hypothesize that one function of the P and L rings is to seal the outer membrane after motor disassembly.

scholarly journals High Throughput Cryo-Electron Tomography: Towards Molecular Architecture of Spirochetal Flagellar Motor in situ

2010 ◽  
Vol 16 (S2) ◽  
pp. 1070-1071
Author(s):  
J Liu ◽  
S Norris
Keyword(s):  
High Throughput ◽  
Electron Tomography ◽  
Flagellar Motor ◽  
Molecular Architecture ◽  
Cryo Electron Tomography

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

scholarly journals The flagellar motor of Vibrio alginolyticus undergoes major structural remodeling during rotational switching

2020 ◽  
Author(s):  
Brittany L. Carroll ◽  
Tatsuro Nishikino ◽  
Wangbiao Guo ◽  
Shiwei Zhu ◽  
Seiji Kojima ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Direct Evidence ◽  
Electron Tomography ◽  
Vibrio Alginolyticus ◽  
Flagellar Motor ◽  
Large Rearrangement ◽  
Structural Remodeling ◽  
Cryo Electron Tomography ◽  
Ring Structures ◽  
Bacterial Flagellar Motor

ABSTRACTThe bacterial flagellar motor is an intricate nanomachine that switches rotational directions between counterclockwise (CCW) and clockwise (CW) to direct the migration of the cell. The cytoplasmic ring (C-ring) of the motor, which is composed of FliG, FliM, and FliN, is known for controlling the rotational sense of the flagellum. However, the mechanism underlying rotational switching remains elusive. Here, we deployed cryo-electron tomography to visualize the C-ring in two rotational biased mutants (CCW-biased fliG-G214S and CW-locked fliG-G215A) in Vibrio alginolyticus. Sub-tomogram averaging was utilized to resolve two distinct conformations of the C-ring. Comparison of the C-ring structures in two rotational senses provide direct evidence that the C-ring undergoes major structural remodeling during rotational switch. Specifically, FliG conformational changes elicit a large rearrangement of the C-ring that coincides with rotational switching, whereas FliM and FliN form a spiral-shaped base of the C-ring, likely stabilizing the C-ring during the conformational remodeling.

scholarly journals Bacterial flagellar motor PL-ring disassembly Sub-complexes are widespread and ancient

2019 ◽  
Author(s):  
Mohammed Kaplan ◽  
Michael J. Sweredoski ◽  
João P.G.L.M. Rodrigues ◽  
Elitza I. Tocheva ◽  
Yi-Wei Chang ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Electron Tomography ◽  
Complex Structures ◽  
Flagellar Motor ◽  
Additional Species ◽  
Cellular Evolution ◽  
Cryo Electron Tomography ◽  
Show Evidence ◽  
Bacterial Flagellar Motor ◽  
Horizontal Transfers

AbstractThe bacterial flagellar motor is an amazing nanomachine. Understanding how such complex structures arose is crucial to our understanding of cellular evolution. We and others recently reported that in several Gammaproteobacterial species, a relic sub-complex comprising the decorated P- and L-rings persists in the outer membrane after flagellum disassembly. Imaging nine additional species with cryo-electron tomography, here we show that this sub-complex persists after flagellum disassembly in other phyla as well. Bioinformatic analyses fail to show evidence of any recent horizontal transfers of the P- and L-ring genes, suggesting that this sub-complex and its persistence is an ancient and conserved feature of the flagellar motor. We hypothesize that one function of the P- and L-rings is to seal the outer membrane after motor disassembly.

scholarly journals The flagellar motor of Vibrio alginolyticus undergoes major structural remodeling during rotational switching

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Brittany L Carroll ◽  
Tatsuro Nishikino ◽  
Wangbiao Guo ◽  
Shiwei Zhu ◽  
Seiji Kojima ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Electron Tomography ◽  
Protein Composition ◽  
Vibrio Alginolyticus ◽  
Flagellar Motor ◽  
Conformational Rearrangement ◽  
Structural Remodeling ◽  
Cryo Electron Tomography ◽  
Bacterial Flagellar Motor ◽  
Rotational Direction

The bacterial flagellar motor switches rotational direction between counterclockwise (CCW) and clockwise (CW) to direct the migration of the cell. The cytoplasmic ring (C-ring) of the motor, which is composed of FliG, FliM, and FliN, is known for controlling the rotational sense of the flagellum. However, the mechanism underlying rotational switching remains elusive. Here, we deployed cryo-electron tomography to visualize the C-ring in two rotational biased mutants in Vibrio alginolyticus. We determined the C-ring molecular architectures, providing novel insights into the mechanism of rotational switching. We report that the C-ring maintained 34-fold symmetry in both rotational senses, and the protein composition remained constant. The two structures show FliG conformational changes elicit a large conformational rearrangement of the rotor complex that coincides with rotational switching of the flagellum. FliM and FliN form a stable spiral-shaped base of the C-ring, likely stabilizing the C-ring during the conformational remodeling.

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