title: Myosin complexed with ADP and blebbistatin reversibly adopts a conformation resembling the start point of the working stroke.
abstract: The powerstroke of the myosin motor is the basis of cell division and bodily movement, but has eluded empirical description due to the short lifetime and low abundance of intermediates during force generation. To gain insight into this process, we used well-established single-tryptophan and pyrene fluorescent sensors and electron microscopy to characterize the structural and kinetic properties of myosin complexed with ADP and blebbistatin, a widely used inhibitor. We found that blebbistatin does not weaken the tight actin binding of myosin.ADP, but unexpectedly it induces lever priming, a process for which the gamma-phosphate of ATP (or its analog) had been thought necessary. The results indicate that a significant fraction of the myosin.ADP.blebbistatin complex populates a previously inaccessible conformation of myosin resembling the start of the powerstroke.
authors.affiliation: Department of Biochemistry, Eötvös University, H-1117 Budapest, Pázmány Peter Setany 1/C, Hungary.
authors.forename: Balázs
authors.initials: B
authors.lastname: Takács
authors.forename: Neil
authors.initials: N
authors.lastname: Billington
authors.forename: Máté
authors.initials: M
authors.lastname: Gyimesi
authors.forename: Bálint
authors.initials: B
authors.lastname: Kintses
authors.forename: András
authors.initials: A
authors.lastname: Málnási-Csizmadia
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Knight
authors.forename: Mihály
authors.initials: M
authors.lastname: Kovács
mesh_terms: D000244:Adenosine Diphosphate / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000737:chemistry; D000818:Animals; D001665:Binding Sites; D004023:Dictyostelium / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000737:chemistry; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry*; D007700:Kinetics; D008854:Microscopy, Electron / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D008954:Models, Biological; D008968:Molecular Conformation; D009218:Myosins / Q000737:chemistry*; D011487:Protein Conformation; D011817:Rabbits
chemical_list: D005456:Fluorescent Dyes; D006576:Heterocyclic Compounds, 4 or More Rings; C472645:blebbistatin; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D009218:Myosins