Direct observation of the mechanochemical coupling in myosin Va during processive movement.

ABSTRACT: Myosin Va transports intracellular cargoes along actin filaments in cells. This processive, two-headed motor takes multiple 36-nm steps in which the two heads swing forward alternately towards the barbed end of actin driven by ATP hydrolysis. The ability of myosin Va to move processively is a function of its long lever arm, the high duty ratio of its kinetic cycle and the gating of the kinetics between the two heads such that ADP release from the lead head is greatly retarded. Mechanical studies at the multiple- and the single-molecule level suggest that there is tight coupling (that is, one ATP is hydrolysed per power stroke), but this has not been directly demonstrated. We therefore investigated the coordination between the ATPase mechanism of the two heads of myosin Va and directly visu

SUBMITTER: Sakamoto T 

PROVIDER: S-EPMC2775414 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature