A mechanism for microtubule depolymerization by KinI kinesins

Mol Cell. 2002 Apr;9(4):903-9. doi: 10.1016/s1097-2765(02)00503-8.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Adenylyl Imidodiphosphate / metabolism
  • Animals
  • Biomechanical Phenomena
  • Biopolymers / metabolism
  • Dimerization
  • Kinesin / chemistry
  • Kinesin / metabolism*
  • Macromolecular Substances
  • Microscopy, Electron
  • Microtubules / metabolism*
  • Models, Chemical
  • Models, Molecular
  • Molecular Motor Proteins / metabolism*
  • Peptide Fragments / chemistry
  • Peptide Fragments / metabolism
  • Plasmodium falciparum / metabolism*
  • Protein Conformation
  • Protein Interaction Mapping
  • Protein Structure, Tertiary
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / metabolism*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Tubulin / chemistry
  • Tubulin / metabolism*

Substances

  • Biopolymers
  • Macromolecular Substances
  • Molecular Motor Proteins
  • Peptide Fragments
  • Protozoan Proteins
  • Recombinant Fusion Proteins
  • Tubulin
  • Adenylyl Imidodiphosphate
  • Adenosine Triphosphate
  • Kinesin