Abstract
We have identified dimeric kinesin mutants that become stalled on the microtubule after one ATP turnover, unable to bind and hydrolyze ATP at their second site. We have used these mutants to determine the regulatory signal that allows ATP to bind to the forward head, such that processive movement can continue. The results show that phosphate release occurs from the rearward head before detachment, and detachment triggers active-site accessibility for ATP binding at the forward head. This mechanism, in which the rearward head controls the behavior of the forward head, may be conserved among processive motors.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adenosine Triphosphate / metabolism
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Animals
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Dimerization
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Drosophila Proteins / chemistry*
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Drosophila Proteins / genetics
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Drosophila Proteins / metabolism
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Drosophila melanogaster / genetics
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Drosophila melanogaster / metabolism
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Humans
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In Vitro Techniques
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Kinesins / chemistry*
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Kinesins / genetics
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Kinesins / metabolism
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Kinetics
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Macromolecular Substances
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Microtubules / metabolism
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Models, Biological
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Models, Molecular
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Molecular Motor Proteins / chemistry*
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Molecular Motor Proteins / genetics
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Molecular Motor Proteins / metabolism
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Mutagenesis, Site-Directed
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Rats
Substances
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Drosophila Proteins
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Macromolecular Substances
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Molecular Motor Proteins
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Adenosine Triphosphate
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Kinesins