The presence and absence of periplasmic rings in bacterial flagellar motors correlates with stator type
Abstract
The bacterial flagellar motor, a cell-envelope-embedded macromolecular machine that functions as a cellular propeller, exhibits significant structural variability between species. Different torque-generating stator modules allow motors to operate in different pH, salt or viscosity levels. How such diversity evolved is unknown. Here, we use electron cryo-tomography to determine the in situ macromolecular structures of three Gammaproteobacteria motors: Legionella pneumophila, Pseudomonas aeruginosa, and Shewanella oneidensis, providing the first views of intact motors with dual stator systems. Complementing our imaging with bioinformatics analysis, we find a correlation between the motor’s stator system and its structural elaboration. Motors with a single H+-driven stator have only the core periplasmic P- and L-rings; those with dual H+-driven stators have an elaborated P-ring; and motors with Na+ or Na+/H+-driven stators have both their P- and L-rings embellished. Our results suggest an evolution of structural elaboration that may have enabled pathogenic bacteria to colonize higher-viscosity environments in animal hosts.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 16, 2019
- Source ID
- 10.7554/elife.43487
Entities
People
- Andreas Kjær
- Ariane Briegel
- Catherine M. Oikonomou
- Davi R Ortega
- Debnath Ghosal
- Grant Jensen
- Mohamed Y El-Naggar
- Mohammed Kaplan
- Poorna Subramanian
- Sahand Pirbadian
Organizations
- Air Force Office of Scientific Research
- California Institute of Technology
- Dutch Research Council
- National Institutes of Health
- University of Southern California