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Publication Abstract from PubMed

Molecular motors produce force when they interact with their cellular tracks. For myosin motors, the primary force-generating state has MgADP tightly bound, whereas myosin is strongly bound to actin. We have generated an 8-A cryoEM reconstruction of this state for myosin V and used molecular dynamics flexed fitting for model building. We compare this state to the subsequent state on actin (Rigor). The ADP-bound structure reveals that the actin-binding cleft is closed, even though MgADP is tightly bound. This state is accomplished by a previously unseen conformation of the beta-sheet underlying the nucleotide pocket. The transition from the force-generating ADP state to Rigor requires a 9.5 degrees rotation of the myosin lever arm, coupled to a beta-sheet rearrangement. Thus, the structure reveals the detailed rearrangements underlying myosin force generation as well as the basis of strain-dependent ADP release that is essential for processive myosins, such as myosin V.

Force-producing ADP state of myosin bound to actin.,Wulf SF, Ropars V, Fujita-Becker S, Oster M, Hofhaus G, Trabuco LG, Pylypenko O, Sweeney HL, Houdusse AM, Schroder RR Proc Natl Acad Sci U S A. 2016 Mar 29;113(13):E1844-52. doi:, 10.1073/pnas.1516598113. Epub 2016 Mar 14. PMID:26976594^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.