Switch I and Switch II Mutants Differentially Impact the Recovery Stroke in Myosin V

Abstract

Myosins generate force by coupling structural changes in the active site to a large rotation of the light chain binding domain or lever arm during specific steps of the ATPase cycle. The recovery stroke, which is associated with movement of the lever arm into the pre-power stroke conformation is crucial for priming the motor for the subsequent force generating steps. In our previous work we have examined the recovery stroke in real time with a high resolution FRET system that utilizes FRET between the N-terminus of myosin V and calmodulin bound to the first IQ domain.