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A mechanism for microtubule depolymerization by KinI kinesins.

Carolyn A Moores·Ming Yu·Jun Guo·Christophe Beraud·Roman Sakowicz·Ronald A Milligan
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Abstract

Whereas most kinesins motor along microtubules, KinI kinesins are microtubule depolymerizing machines. Surprisingly, we found that a KinI fragment consisting of only the motor core is capable of ATP-dependent depolymerization. The motor binds along microtubules in all nucleotide states, but in the presence of AMPPNP, microtubule depolymerization also occurs. Structural characterization of the products of AMPPNP-induced destabilization revealed a snapshot of the disassembly machine in action as it precisely deformed a tubulin dimer. While conventional kinesins use the energy of ATP binding to execute a "powerstroke," KinIs use it to bend the underlying protofilament. Thus, the relatively small class-specific differences within the KinI motor core modulate a fundamentally conserved mode of interaction with microtubules to produce a unique depolymerizing activity.

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Adenosine TriphosphateAdenylyl ImidodiphosphateAnimalsBiomechanical PhenomenaBiopolymersDimerizationKinesinsMacromolecular SubstancesMicroscopy, ElectronMicrotubulesModels, ChemicalModels, MolecularMolecular Motor ProteinsPeptide FragmentsPlasmodium falciparumProtein ConformationProtein Interaction MappingProtein Structure, TertiaryProtozoan ProteinsRecombinant Fusion ProteinsTubulinJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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Carolyn A Moores, Ming Yu, Jun Guo, Christophe Beraud, Roman Sakowicz, Ronald A Milligan. 2002. A mechanism for microtubule depolymerization by KinI kinesins.. https://doi.org/10.1016/s1097-2765(02)00503-8

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