title: Dynamics of the unbound head during myosin V processive translocation.
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.
authors.affiliation: Stanford University School of Medicine, Beckman Center, 279 Campus Drive, Stanford, California 94305-5307, USA.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Dunn
authors.forename: James A
authors.initials: JA
authors.lastname: Spudich
mesh_terms: D000818:Animals; D002645:Chickens; D008954:Models, Biological; D024701:Myosin Type V / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D021381:Protein Transport; D013997:Time Factors
chemical_list: D024701:Myosin Type V