Structural Model for Tubulin Recognition and Deformation by kinesin-13 Microtubule Depolymerases

Cell Rep. 2013 Mar 28;3(3):759-68. doi: 10.1016/j.celrep.2013.01.030. Epub 2013 Feb 21.

Abstract

To elucidate the structural basis of the mechanism of microtubule depolymerization by kinesin-13s, we analyzed complexes of tubulin and the Drosophila melanogaster kinesin-13 KLP10A by electron microscopy (EM) and fluorescence polarization microscopy. We report a nanometer-resolution (1.1 nm) cryo-EM three-dimensional structure of the KLP10A head domain (KLP10AHD) bound to curved tubulin. We found that binding of KLP10AHD induces a distinct tubulin configuration with displacement (shear) between tubulin subunits in addition to curvature. In this configuration, the kinesin-binding site differs from that in straight tubulin, providing an explanation for the distinct interaction modes of kinesin-13s with the microtubule lattice or its ends. The KLP10AHD-tubulin interface comprises three areas of interaction, suggesting a crossbow-type tubulin-bending mechanism. These areas include the kinesin-13 family conserved KVD residues, and as predicted from the crossbow model, mutating these residues changes the orientation and mobility of KLP10AHDs interacting with the microtubule.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Drosophila Proteins / chemistry*
  • Drosophila Proteins / metabolism
  • Drosophila Proteins / ultrastructure
  • Drosophila melanogaster / chemistry
  • Drosophila melanogaster / metabolism*
  • Kinesin / chemistry*
  • Kinesin / metabolism
  • Kinesin / ultrastructure
  • Microtubules / metabolism*
  • Microtubules / ultrastructure
  • Molecular Dynamics Simulation*
  • Molecular Sequence Data
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein Subunits / metabolism
  • Tubulin / chemistry*
  • Tubulin / metabolism
  • Tubulin / ultrastructure

Substances

  • Drosophila Proteins
  • Protein Subunits
  • Tubulin
  • KLP10A protein, Drosophila
  • Kinesin

Associated data

  • PDB/3J2U