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Biophysical Characterization of Flagellar Motor Functions
Published on: January 18, 2017
8.8K
A rotary motor drives Flavobacterium gliding
Abhishek Shrivastava1, Pushkar P Lele1, Howard C Berg1
1Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Current Biology : CB
|January 27, 2015
Summary
The bacterial gliding motor of Flavobacterium johnsoniae, powered by protonmotive force, utilizes SprB protein filaments for locomotion. This motor operates at constant speed, similar to other proton-driven rotary motors.
Area of Science:
- Microbiology
- Bacterial Motility
Background:
- Flavobacterium johnsoniae exhibits gliding motility without pili or flagella, powered by protonmotive force.
- The specific molecular machinery driving this bacterial gliding motion remained largely unknown.
- Surface adhesin SprB forms filaments involved in F. johnsoniae gliding.
Purpose of the Study:
- To investigate the mechanism and characteristics of the F. johnsoniae gliding motor.
- To understand the role of SprB filaments in bacterial surface translocation.
Main Methods:
- Shearing F. johnsoniae cells to reduce SprB filament size and number.
- Tethering cells to glass surfaces using anti-SprB antibodies.
- Observing and measuring cell rotation and speed.
Main Results:
- Tethered cells rotated at high speeds (≥1 Hz), indicating a powerful motor.
- The gliding motor was found to operate at a constant speed, not constant torque.
- SprB filaments are crucial for the observed gliding motility.
Conclusions:
- The F. johnsoniae gliding motor is a novel proton-driven rotary motor.
- Its operation at constant speed distinguishes it from other known rotary motors.
- SprB filaments are essential components of the bacterial gliding apparatus.
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