Coordinated switching of bacterial flagellar motors: evidence for direct motor-motor coupling?

Phys Rev Lett. 2013 Apr 12;110(15):158703. doi: 10.1103/PhysRevLett.110.158703. Epub 2013 Apr 9.


The swimming of Escherichia coli is powered by its multiple flagellar motors. Each motor spins either clockwise or counterclockwise, under the control of an intracellular regulator, CheY-P. There can be two mechanisms (extrinsic and intrinsic) to coordinate the switching of bacterial motors. The extrinsic one arises from the fact that different motors in the same cell sense a common input (CheY-P) which fluctuates near the motors' response threshold. An alternative, intrinsic mechanism is direct motor-motor coupling which makes synchronized switching energetically favorable. Here, we develop simple models for both mechanisms and uncover their different hallmarks. A quantitative comparison to the recent experiments suggests that the direct coupling mechanism may be accountable for the observed sharp correlation between motors in a single Escherichia coli. Possible origins of this coupling (e.g., hydrodynamic interaction) are discussed.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bacterial Proteins / physiology*
  • Chemotaxis / physiology*
  • Escherichia coli / physiology*
  • Flagella / physiology*
  • Hydrodynamics
  • Membrane Proteins / physiology*
  • Methyl-Accepting Chemotaxis Proteins
  • Models, Biological*
  • Swimming


  • Bacterial Proteins
  • Membrane Proteins
  • Methyl-Accepting Chemotaxis Proteins
  • cheY protein, E coli