A conventional kinesin molecule travels continuously along a microtubule, in discrete steps of 8 nm. This processive movement is generally explained by models in which the two heads of a kinesin move in a hand-over-hand fashion. In order to prove this model, we have constructed a heterodimeric kinesin in which the mechanochemical cycle rate of one of the heads is considerably slower than the otherÅfs. Optical trapping nanometry experiments showed that a single heterodimeric kinesin exhibits fast and slow, 8 nm-steps alternately. Our results provide the first, direct evidence for the hand-over-hand model.
Co-authors : K. Kaseda (Gene Function Research Center, AIST), H. Higuchi (Tohoku University)
K. Kaseda, H. Higuchi, and K. Hirose : Proc. Natl. Acad. Sci., USA. 99 (25), 16058-16063 (2002).
K. Kaseda, H. Higuchi, and K. Hirose : Nature Cell Biology, 5(12), 1079-1082 (2003)..
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Alternate fast and slow steps of a heterodimer kinesin |
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| Relational Information |
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AIST Today Vol. 4, No.9 (2004) 20
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No.14 Autumn 2004
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