A structural pathway for activation of the kinesin motor ATPase.

Published

Journal Article

Molecular motors move along actin or microtubules by rapidly hydrolyzing ATP and undergoing changes in filament-binding affinity with steps of the nucleotide hydrolysis cycle. It is generally accepted that motor binding to its filament greatly increases the rate of ATP hydrolysis, but the structural changes in the motor associated with ATPase activation are not known. To identify the conformational changes underlying motor movement on its filament, we solved the crystal structures of three kinesin mutants that decouple nucleotide and microtubule binding by the motor, and block microtubule-activated, but not basal, ATPase activity. Conformational changes in the structures include a disordered loop and helices in the switch I region and a visible switch II loop, which is disordered in wild-type structures. Switch I moved closer to the bound nucleotide in two mutant structures, perturbing water-mediated interactions with the Mg2+. This could weaken Mg2+ binding and accelerate ADP release to activate the motor ATPASE: The structural changes we observe define a signaling pathway within the motor for ATPase activation that is likely to be essential for motor movement on microtubules.

Full Text

Duke Authors

Cited Authors

  • Yun, M; Zhang, X; Park, CG; Park, HW; Endow, SA

Published Date

  • June 1, 2001

Published In

Volume / Issue

  • 20 / 11

Start / End Page

  • 2611 - 2618

PubMed ID

  • 11387196

Pubmed Central ID

  • 11387196

International Standard Serial Number (ISSN)

  • 0261-4189

Digital Object Identifier (DOI)

  • 10.1093/emboj/20.11.2611

Language

  • eng

Conference Location

  • England