It’s been long known that the bacterial flagellum can spin in one direction and then quickly reverse directions and spin in the other. A recent issue of Nature has an article titled, “Structure of the torque ring of the flagellar motor and the molecular basis for rotational switching” which elucidates some of the biomechanical properties of the FliG motor protein that allows this rotation switch to occur: The flagellar motor drives the rotation of flagellar filaments at hundreds of revolutions per second, efficiently propelling bacteria through viscous media. The motor uses the potential energy from an electrochemical gradient of cations across the cytoplasmic membrane to generate torque. A rapid switch from anticlockwise to clockwise rotation determines whether a bacterium runs Read More ›