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Overlapping hand-over-hand mechanism of single molecular motility of cytoplasmic dynein.

ABSTRACT: Structural differences between dynein and kinesin suggest a unique molecular mechanism of dynein motility. Measuring the mechanical properties of a single molecule of dynein is crucial for revealing the mechanisms underlying its movement. We measured the step size and force produced by single molecules of active cytoplasmic dynein by using an optical trap and fluorescence imaging with a high temporal resolution. The velocity of dynein movement, 800 nm/s, is consistent with that reported in cells. The maximum force of 7-8 pN was independent of the ATP concentration and similar to that of kinesin. Dynein exhibited forward and occasional backwards steps of approximately 8 nm, independent of load. It is suggested that the large dynein heads take 16-nm steps by using an overlapping hand-over-hand mechanism.

SUBMITTER: Toba S

PROVIDER: S-EPMC1424663 | biostudies-literature | 2006 Apr

REPOSITORIES: biostudies-literature

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Overlapping hand-over-hand mechanism of single molecular motility of cytoplasmic dynein.

Toba Shiori S Watanabe Tomonobu M TM Yamaguchi-Okimoto Lisa L Toyoshima Yoko Yano YY Higuchi Hideo H

Proceedings of the National Academy of Sciences of the United States of America 20060403 15

Structural differences between dynein and kinesin suggest a unique molecular mechanism of dynein motility. Measuring the mechanical properties of a single molecule of dynein is crucial for revealing the mechanisms underlying its movement. We measured the step size and force produced by single molecules of active cytoplasmic dynein by using an optical trap and fluorescence imaging with a high temporal resolution. The velocity of dynein movement, 800 nm/s, is consistent with that reported in cells ...[more]

PMID: 16585530

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