Myosin VI Lever Arm Rotation: Fixed or Variable?

Abstract

Two recent articles addressed the power-stroke of myosin VI molecules during stepping. Although both groups measured the angles of fluorescent probes attached on the myosin VI molecule lever arm using polarized fluorescence techniques, they differ about whether the myosin VI lever arm rotation is fixed1 or variable2. Here we discuss the causes of the discrepancy between the two studies and the implications for myosin VI processive motility.