The bacterial flagellar motor and its structural diversity.

Area of Science:

• Microbiology
• Molecular Biology
• Biophysics

Background:

• The bacterial flagellum functions as a rotary motor, crucial for motility.
• This motor is powered by ion electrochemical potential differences across the cytoplasmic membrane.
• Key components include the MS ring, C ring, rod, and export apparatus.

Purpose of the Study:

• To review the current understanding of bacterial flagellar motor structure, function, and assembly.
• To compare flagellar motors from Salmonella (H(+)-driven) and marine Vibrio species (Na(+)-driven).

Main Methods:

• Comparative analysis of conserved and species-specific flagellar motor structures.
• Review of experimental data on flagellar motor dynamics and function.
• Synthesis of existing knowledge on flagellar motor assembly.

Main Results:

• The bacterial flagellar motor is a conserved structure with dynamic C ring and export apparatus.
• Salmonella flagellar motors (H(+)-driven) operate at approximately 300 Hz.
• Marine Vibrio flagellar motors (Na(+)-driven) exhibit significantly faster rotation, up to 1700 Hz.

Conclusions:

• Bacterial flagellar motors display conserved core structures but vary in ion-driving species and rotational speed.
• Understanding the structure-function relationship of these motors is key to bacterial motility research.
• Further research into assembly mechanisms and accessory structures can reveal more about flagellar motor diversity.