Flexible light-chain and helical structure of F-actin explain the movement and step size of myosin-VI.
Myosin-VI is a dimeric isoform of unconventional myosins. Single molecule experiments indicate that myosin-VI and myosin-V are processive molecular motors, but travel toward opposite ends of filamentous actin. Structural studies show several differences between myosin-V and VI, including a significant difference in the light-chain domain connecting the motor domains. Combining the measured kinetics of myosin-VI with the elasticity of the light chains, and the helical structure of F-actin, we compare and contrast the motility of myosin-VI with myosin-V. We show that the elastic properties of the light-chain domain control the stepping behavior of these motors. Simple models incorporating the motor elastic energy can quantitatively capture most of the observed data. Implications of our result for other processive motors are discussed.
Lan
Ganhui
G
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD, USA.
Sun
Sean X
SX
D000199:Actins / Q000737:chemistry*; D001665:Binding Sites; D001703:Biophysics / Q000379:methods*; D020134:Catalytic Domain; D019281:Dimerization; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D009010:Monte Carlo Method; D018995:Myosin Heavy Chains / Q000737:chemistry*; D024701:Myosin Type V / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary
D000199:Actins; C089785:myosin VI; D024701:Myosin Type V; D018995:Myosin Heavy Chains