FRET and optical trapping reveal mechanisms of actin activation of the power stroke and phosphate release in myosin V.

ABSTRACT: Myosins generate force and motion by precisely coordinating their mechanical and chemical cycles, but the nature and timing of this coordination remains controversial. We utilized a FRET approach to examine the kinetics of structural changes in the force-generating lever arm in myosin V. We directly compared the FRET results with single-molecule mechanical events examined by optical trapping. We introduced a mutation (S217A) in the conserved switch I region of the active site to examine how myosin couples structural changes in the actin- and nucleotide-binding regions with force generation. Specifically, S217A enhanced the maximum rate of lever arm priming (recovery stroke) while slowing ATP hydrolysis, demonstrating that it uncouples these two steps. We determined that the mutation dramat

SUBMITTER: Gunther LK 

PROVIDER: S-EPMC7762931 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature