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Updated: Jul 17, 2026

Dissecting Mechanoenzymatic Properties of Processive Myosins with Ultrafast Force-Clamp Spectroscopy
Published on: July 1, 2021
Dynamics of the unbound head during myosin V processive translocation
Alexander R Dunn1, James A Spudich
1Stanford University School of Medicine, Beckman Center, 279 Campus Drive, Stanford, California 94305-5307, USA.
Abstract:
Myosin V moves cargoes along actin filaments by walking hand over hand. Although numerous studies support the basic hand-over-hand model, little is known about the fleeting intermediate that occurs when the rear head detaches from the filament. Here we use submillisecond dark-field imaging of gold nanoparticle-labeled myosin V to directly observe the free head as it releases from the actin filament, diffuses forward and rebinds. We find that the unbound head rotates freely about the lever-arm junction, a trait that likely facilitates travel through crowded actin meshworks.
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