How white noise generates power-law switching in bacterial flagellar motors

Phys Rev Lett. 2005 May 27;94(20):208101. doi: 10.1103/PhysRevLett.94.208101. Epub 2005 May 25.


The clockwise (CW) or counterclockwise (CCW) spinning of a bacterial flagellar motor is controlled by the concentration [Y] of a phosphorylated protein, CheY-P. Representing the stochastic switching behavior of the motor by a dynamical two-state (CW and CCW) model, whose energy levels fluctuate in time (t) as [Y](t) fluctuates, we show that temporal fluctuations in [Y](t) can generate a power-law distribution for the durations of the CCW states, in agreement with recent experiments. Correlations between the duration times of nearby CCW (CW) intervals are predicted by our model, and shown to exist in the experimental data and to affect the power spectrum for motor switching.

Publication types

  • Comparative Study
  • Evaluation Study
  • Validation Study

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / physiology*
  • Computer Simulation
  • Escherichia coli / chemistry
  • Escherichia coli / physiology*
  • Flagella / chemistry
  • Flagella / physiology*
  • Membrane Proteins / chemistry
  • Membrane Proteins / physiology*
  • Methyl-Accepting Chemotaxis Proteins
  • Models, Biological*
  • Models, Chemical
  • Models, Statistical*
  • Molecular Motor Proteins / chemistry
  • Molecular Motor Proteins / physiology*
  • Motion
  • Normal Distribution


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