A structural model for monastrol inhibition of dimeric kinesin Eg5.

ABSTRACT: Eg5 or KSP is a homotetrameric Kinesin-5 involved in centrosome separation and assembly of the bipolar mitotic spindle. Analytical gel filtration of purified protein and cryo-electron microscopy (cryo-EM) of unidirectional shadowed microtubule-Eg5 complexes have been used to identify the stable dimer Eg5-513. The motility assays show that Eg5-513 promotes robust plus-end-directed microtubule gliding at a rate similar to that of homotetrameric Eg5 in vitro. Eg5-513 exhibits slow ATP turnover, high affinity for ATP, and a weakened affinity for microtubules when compared to monomeric Eg5. We show here that the Eg5-513 dimer binds microtubules with both heads to two adjacent tubulin heterodimers along the same microtubule protofilament. Under all nucleotide conditions tested, there were no vis

SUBMITTER: Krzysiak TC 

PROVIDER: S-EPMC1462975 | biostudies-literature | 2006 May

REPOSITORIES: biostudies-literature