Two Distinct Modes of Processive Kinesin Movement in Mixtures of ATP and AMP-PNP
Open Access
- 29 October 2007
- journal article
- Published by Rockefeller University Press in The Journal of general physiology
- Vol. 130 (5), 445-455
- https://doi.org/10.1085/jgp.200709866
Abstract
An enzyme is frequently conceived of as having a single functional mechanism. This is particularly true for motor enzymes, where the necessity for tight coupling of mechanical and chemical cycles imposes rigid constraints on the reaction pathway. In mixtures of substrate (ATP) and an inhibitor (adenosine 5′-(β,γ-imido)triphosphate or AMP-PNP), single kinesin molecules move on microtubules in two distinct types of multiple-turnover “runs” that differ in their susceptibility to inhibition. Longer (less susceptible) runs are consistent with movement driven by the alternating-sites mechanism previously proposed for uninhibited kinesin. In contrast, kinesin molecules in shorter runs step with AMP-PNP continuously bound to one of the two active sites of the enzyme. Thus, in this mixture of substrate and inhibitor, kinesin can function as a motor enzyme using either of two distinct mechanisms. In one of these, the enzyme can accomplish high-duty-ratio processive movement without alternating-sites ATP hydrolysis.Keywords
This publication has 43 references indexed in Scilit:
- Vik1 Modulates Microtubule-Kar3 Interactions through a Motor Domain that Lacks an Active SiteCell, 2007
- Backsteps induced by nucleotide analogs suggest the front head of kinesin is gated by strainProceedings of the National Academy of Sciences of the United States of America, 2006
- Alternate fast and slow stepping of a heterodimeric kinesin moleculeNature, 2003
- Chemomechanical coupling of the forward and backward steps of single kinesin moleculesNature, 2002
- A new look at the microtubule binding patterns of dimeric kinesinsJournal of Molecular Biology, 2000
- One-Headed Kinesin Derivatives Move by a Nonprocessive, Low-Duty Ratio Mechanism Unlike That of Two-Headed KinesinBiochemistry, 1998
- Alternating Site Mechanism of the Kinesin ATPaseBiochemistry, 1998
- Weak and Strong States of Kinesin and ncdJournal of Molecular Biology, 1996
- Nucleotide-dependent angular change in kinesin motor domain bound to tubulinNature, 1995
- Failure of a single-headed kinesin to track parallel to microtubule protofilamentsNature, 1995