A Lever-arm Rotation Drives Motility of the Minus-end-directed Kinesin Ncd.
From: The Howard Hughes Medical Institute, and the Department of Cellular and Molecular Pharmacology, University of California San Francisco, 600 16th Street, San Francisco, California 94107, USA.
Nature
- Publish Date: Feb 2006
- ISSN: 1476-4687
- Volume: 439
- Issue: 7078
- Pages: 875-8
- Medium: Internet
- Language: English
- Citation (JAMA): Endres Nicholas F, Yoshioka Craig, Milligan Ronald A, et al. A Lever-arm Rotation Drives Motility of the Minus-end-directed Kinesin Ncd.. Nature Feb 2006;439:875-8
Abstract
Kinesins are microtubule-based motor proteins that power intracellular transport. Most kinesin motors, exemplified by Kinesin-1, move towards the microtubule plus end, and the structural changes that govern this directional preference have been described. By contrast, the nature and timing of the structural changes underlying the minus-end-directed motility of Kinesin-14 motors (such as Drosophila Ncd) are less well understood. Using cryo-electron microscopy, here we demonstrate that a coiled-coil mechanical element of microtubule-bound Ncd rotates approximately 70 degrees towards the minus end upon ATP binding. Extending or shortening this coiled coil increases or decreases velocity, respectively, without affecting ATPase activity. An unusual Ncd mutant that lacks directional preference shows unstable nucleotide-dependent conformations of its coiled coil, underscoring the role of this mechanical element in motility. These results show that the force-producing conformational change in Ncd occurs on ATP binding, as in other kinesins, but involves the swing of a lever-arm mechanical element similar to that described for myosins.
Mesh Headings (Keywords): Adenosine Triphosphate, Animals, Cryoelectron Microscopy, Drosophila Proteins, Kinesin, Microtubules, Models, Biological, Models, Molecular, Mutation, Protein Conformation, Rotation, Structure-Activity Relationship
Check for Full Text / PubMed Unique Identifier (PMID): 16382238
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.