1f9t
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CRYSTAL STRUCTURES OF KINESIN MUTANTS REVEAL A SIGNALLING PATHWAY FOR ACTIVATION OF THE MOTOR ATPASE
OverviewOverview
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.
About this StructureAbout this Structure
1F9T is a Single protein structure of sequence from Saccharomyces cerevisiae with MG and ADP as ligands. Full crystallographic information is available from OCA.
ReferenceReference
A structural pathway for activation of the kinesin motor ATPase., Yun M, Zhang X, Park CG, Park HW, Endow SA, EMBO J. 2001 Jun 1;20(11):2611-8. PMID:11387196
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