Structural dynamics of myosin 5 during processive motion revealed by interferometric scattering microscopy.
Myosin 5a is a dual-headed molecular motor that transports cargo along actin filaments. By following the motion of individual heads with interferometric scattering microscopy at nm spatial and ms temporal precision we found that the detached head occupies a loosely fixed position to one side of actin from which it rebinds in a controlled manner while executing a step. Improving the spatial precision to the sub-nm regime provided evidence for an ångstrom-level structural transition in the motor domain associated with the power stroke. Simultaneous tracking of both heads revealed that consecutive steps follow identical paths to the same side of actin in a compass-like spinning motion demonstrating a symmetrical walking pattern. These results visualize many of the critical unknown aspects of the stepping mechanism of myosin 5 including head-head coordination, the origin of lever-arm motion and the spatiotemporal dynamics of the translocating head during individual steps.
Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Joanna
J
Andrecka
Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Jaime
J
Ortega Arroyo
Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, United States.
Yasuharu
Y
Takagi
Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Gabrielle
G
de Wit
Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Adam
A
Fineberg
Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Lachlan
L
MacKinnon
Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Gavin
G
Young
Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, United States.
James R
JR
Sellers
Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Philipp
P
Kukura
D008841:Actin Cytoskeleton / Q000378:metabolism; D000818:Animals; D001696:Biomechanical Phenomena; D005453:Fluorescence; D021621:Imaging, Three-Dimensional; D051379:Mice; D008857:Microscopy, Interference / Q000379:methods*; D008954:Models, Biological; D009038:Motion; D009218:Myosins / Q000737:chemistry* / Q000378:metabolism*; D011336:Probability; D017434:Protein Structure, Tertiary; D011817:Rabbits
D009218:Myosins
biophysics; molecular motors; myosin; none; single particle tracking; structural biology