Myosin-V stepping kinetics: a molecular model for processivity.

M Rief; R S Rock; A D Mehta; M S Mooseker; R E Cheney; J A Spudich

doi:10.1073/pnas.97.17.9482

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Myosin-V stepping kinetics: a molecular model for processivity.

M Rief·R S Rock·A D Mehta·M S Mooseker·R E Cheney·J A Spudich

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Abstract

Myosin-V is a molecular motor that moves processively along its actin track. We have used a feedback-enhanced optical trap to examine the stepping kinetics of this movement. By analyzing the distribution of time periods separating discrete approximately 36-nm mechanical steps, we characterize the number and duration of rate-limiting biochemical transitions preceding each such step. These data show that myosin-V is a tightly coupled motor whose cycle time is limited by ADP release. On the basis of these results, we propose a model for myosin-V processivity.

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Actins Adenosine Diphosphate Adenosine Triphosphate Animals Brain Calmodulin-Binding Proteins Chickens Feedback Kinetics Lasers Microspheres Models, Biological Molecular Motor Proteins Movement Myosin Type V Nerve Tissue Proteins Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

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M Rief, R S Rock, A D Mehta, M S Mooseker, R E Cheney, J A Spudich. 2000-08-15. Myosin-V stepping kinetics: a molecular model for processivity.. https://doi.org/10.1073/pnas.97.17.9482

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