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Lever Arm Mechanics of Processive Myosins Dawn A. Bonnell, University of Pennsylvania, DMR 0832802 NSEC. Objectives : Apply FIONA, polTIRF and Parallax to Three Unconventional Myosins Determine Stepping Mechanics, Angles and Paths Compare Mechanics with Lever Arm Structures.
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Lever Arm Mechanics of Processive MyosinsDawn A. Bonnell, University of Pennsylvania, DMR 0832802NSEC • Objectives: • Apply FIONA, polTIRF and Parallax to Three • Unconventional Myosins • Determine Stepping Mechanics, Angles and Paths • Compare Mechanics with Lever Arm Structures Three Unconventional Myosins s of Step Size is Related to Lever Arm Stiffness Tilting Motions of Myosin V, VI and X • References: • Sun Y, Schroeder HW 3rd, Beausang JF, Homma K, Ikebe M, Goldman YE. Myosin VI walks "wiggly" on actin with large and variable tilting. Mol Cell. 2007 28:954-64. • Sun Y, McKenna JD, Murray JM, Ostap EM, Goldman YE. Parallax: high accuracy three-dimensional single molecule tracking using split images. Nano Lett. 2009 9:2676-82. • Sun Y, Sato O, Ruhnow F, Arsenault ME, Ikebe M, Goldman YE. Single-molecule stepping and structural dynamics of myosin X. Nat Struct Mol Biol. 2010 17:485-91. • Sun Y, Goldman YE. Lever Arm Mechanics of Processive Myosins. Biophysical J. 2011, Provisionally accepted. • Conclusions: • Lever arm stiffness among myosins V, VI and X are highly variable. • Step size is most variable in myosin VI and least variable in myosin V. • Sideways wobble is compatible with structures and implied stiffness. • Myosin structures are modulated to tune them for specialized functions.