The next NUMEV seminar will take place on Friday, December 2nd at 11am in the Amphi Moreau, Campus Saint Priest.

Dynamics of a bacterial motor at multiple scales:
from protons to polymers

Ashley Nord, Physics and mechanics of biological systems team, Department of Biophysics and Bioengineering, CNRS – CBS, Centre de Biologie Structurale, Montpellier, France

When : Friday, December 2nd at 11am + Lunch

Where : Amphi Moreau, Bâtiment 2 (LMGC), Campus Saint Priest, 860 rue de Saint Priest, Montpellier

Abstract

The bacterial flagellar motor (BFM) is the nanoscale electrochemical rotary motor which spins the flagellum and provides thrust to many species of bacteria. This remarkable self-assembled molecular machine enables bacterial motility and chemotaxis, while also playing a role in surface sensing, infection, and biofilm formation. While we now have atomic level resolution structures of many of the key components of this macromolecular machine, many fundamental mysteries remain regarding its functional dynamics. We use a combination of optical microscopy techniques, magnetic tweezers, genetic manipulation, and mathematical models to quantify and understand the rich dynamics of the BFM at multiple scales. From the nano- to micro-scale, we’ll present an overview of some of our most recent results, including single cell spatial and temporal dynamics of the out-of-equilibrium proton motive force in bacteria, a mechanistic understanding of the dynamic exchange of mechanosensitive torque-generating units, and a torsionally-induced strain-stiffening in the polymer which couples torque from the motor to the flagellum.