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Updated: Jun 2, 2026
06:08
Biophysical Characterization of Flagellar Motor Functions
Published on: January 18, 2017
Motor-driven intracellular transport powers bacterial gliding motility
Mingzhai Sun1, Morgane Wartel, Eric Cascales
1Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA.
Summary
This study reveals that bacteria use directed intracellular transport of protein complexes, acting as molecular motors, to achieve motility on surfaces. This finding uncovers a conserved mechanism for bacterial movement.
Area of Science:
- Microbiology
- Cell Biology
- Biophysics
Background:
- Intracellular protein transport is crucial for cellular processes but unobserved in bacteria.
- Myxococcus xanthus motility models conflict, with debated mechanisms for propulsion.
Purpose of the Study:
- To investigate the mechanism behind Myxococcus xanthus motility on solid surfaces.
- To determine if directed intracellular protein transport exists and contributes to bacterial movement.
Main Methods:
- Utilized fluorescence imaging to visualize protein complex movement.
- Employed force microscopy to measure forces generated by cellular processes.
- Conducted genetic manipulation to probe the roles of specific proteins.
Main Results:
- Demonstrated directional, constant-velocity transport of membrane-bound cytoplasmic complexes along the bacterial cell axis.
- Showed that this intracellular motion is externally transmitted to generate traction forces on substrates.
- Identified these complexes as processive intracellular motors responsible for bacterial motility.
Conclusions:
- Established the existence of a conserved class of processive intracellular motors in bacteria.
- Revealed that bacterial motility on surfaces is driven by the externalization of intracellular motor activity.
- Provided a unified model for Myxococcus xanthus motility, integrating intracellular transport and external force generation.
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