title: Coordinated switching of bacterial flagellar motors: evidence for direct motor-motor coupling?
abstract: 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.
authors.affiliation: IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.affiliation: IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA.
authors.forename: Yuhai
authors.initials: Y
authors.lastname: Tu
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D002633:Chemotaxis / Q000502:physiology*; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins; D005407:Flagella / Q000502:physiology*; D057446:Hydrodynamics; D008565:Membrane Proteins / Q000502:physiology*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008954:Models, Biological; D013550:Swimming
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C000607606:cheY protein, E coli