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Publication Abstract from PubMed

Members of the kinesin-8 motor class have the remarkable ability to both walk towards microtubule plus-ends and depolymerise these ends on arrival, thereby regulating microtubule length. To analyse how kinesin-8 multitasks, we studied the structure and function of the kinesin-8 motor domain. We determined the first crystal structure of a kinesin-8 and used cryo-electron microscopy to calculate the structure of the microtubule-bound motor. Microtubule-bound kinesin-8 reveals a new conformation compared with the crystal structure, including a bent conformation of the alpha4 relay helix and ordering of functionally important loops. The kinesin-8 motor domain does not depolymerise stabilised microtubules with ATP but does form tubulin rings in the presence of a non-hydrolysable ATP analogue. This shows that, by collaborating, kinesin-8 motor domain molecules can release tubulin from microtubules, and that they have a similar mechanical effect on microtubule ends as kinesin-13, which enables depolymerisation. Our data reveal aspects of the molecular mechanism of kinesin-8 motors that contribute to their unique dual motile and depolymerising functions, which are adapted to control microtubule length.

Insight into the molecular mechanism of the multitasking kinesin-8 motor.,Peters C, Brejc K, Belmont L, Bodey AJ, Lee Y, Yu M, Guo J, Sakowicz R, Hartman J, Moores CA EMBO J. 2010 Oct 20;29(20):3437-47. Epub 2010 Sep 3. PMID:20818331^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.