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Updated: Jul 15, 2026
06:08
Biophysical Characterization of Flagellar Motor Functions
Published on: January 18, 2017
Stepwise formation of the bacterial flagellar system
1Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, AZ 85721, USA.
Summary
The bacterial flagellum
Area of Science:
- Evolutionary biology
- Microbiology
- Genomics
Background:
- The bacterial flagellum is a complex molecular machine.
- Its evolutionary origins and diversification across bacterial phyla are poorly understood.
- Flagellar gene clusters vary significantly in size and composition.
Purpose of the Study:
- To investigate the evolutionary origins and diversification of bacterial flagellar genes.
- To identify the ancient core set of flagellar genes present in the last bacterial common ancestor.
- To reconstruct the probable evolutionary pathway of flagellar component assembly.
Main Methods:
- Comparative genomics analysis of 41 flagellated bacterial species from 11 phyla.
- Phylogenetic analysis of all identified flagellar protein homologs.
- Identification of ancient core genes and their evolutionary relationships.
Main Results:
- Identified an ancient core set of 24 structural genes present in the common ancestor of all Bacteria.
- Observed sequence similarity among core genes, suggesting gene duplication and modification.
- Reconstructed a probable evolutionary order for the origin of flagellar components.
Conclusions:
- The bacterial flagellum's core components likely evolved from a single or few precursor genes.
- Successive gene duplication and modification drove the evolution of flagellar complexity.
- This study provides a framework for understanding the evolution of complex molecular machines.
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