Pi release from myosin: A simulation analysis of possible pathways

Citation:

Cecchini M, Alexeev Y, Karplus M. Pi release from myosin: A simulation analysis of possible pathways. Structure. 2010;18 (4) :458-470.

Abstract:

The release of inorg. phosphate (Pi) is an important element in actomyosin function and has been shown to be accelerated by the binding of myosin to actin. To provide information about the structural elements important for Pi release, possible escape pathways from various isolated myosin II structures were detd. by mol. dynamics simulations designed for studying such slow processes. The residues forming the pathways were identified and their role was evaluated by mutant simulations. Pi release was slow in the pre-​powerstroke structure, an important element in preventing the powerstroke prior to actin binding, and was much more rapid for Pi modeled into the post-​rigor and rigor-​like structures. The previously proposed backdoor route was dominant in the pre-​powerstroke and post-​rigor states, whereas a different path was most important in the rigor-​like state. This finding suggested a mechanism for the actin-​activated acceleration of Pi release.