Structural differences between yeast and mammalian microtubules revealed by cryo-EM

J Cell Biol. 2017 Sep 4;216(9):2669-2677. doi: 10.1083/jcb.201612195. Epub 2017 Jun 26.


Microtubules are polymers of αβ-tubulin heterodimers essential for all eukaryotes. Despite sequence conservation, there are significant structural differences between microtubules assembled in vitro from mammalian or budding yeast tubulin. Yeast MTs were not observed to undergo compaction at the interdimer interface as seen for mammalian microtubules upon GTP hydrolysis. Lack of compaction might reflect slower GTP hydrolysis or a different degree of allosteric coupling in the lattice. The microtubule plus end-tracking protein Bim1 binds yeast microtubules both between αβ-tubulin heterodimers, as seen for other organisms, and within tubulin dimers, but binds mammalian tubulin only at interdimer contacts. At the concentrations used in cryo-electron microscopy, Bim1 causes the compaction of yeast microtubules and induces their rapid disassembly. Our studies demonstrate structural differences between yeast and mammalian microtubules that likely underlie their differing polymerization dynamics. These differences may reflect adaptations to the demands of different cell size or range of physiological growth temperatures.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Binding Sites
  • Cell Cycle Proteins / metabolism
  • Cell Cycle Proteins / ultrastructure
  • Cryoelectron Microscopy*
  • Guanosine Triphosphate / metabolism
  • Hydrolysis
  • Microtubule Proteins / metabolism
  • Microtubule Proteins / ultrastructure
  • Microtubules / genetics
  • Microtubules / metabolism
  • Microtubules / ultrastructure*
  • Molecular Dynamics Simulation
  • Protein Binding
  • Protein Multimerization
  • Protein Structure, Quaternary
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / ultrastructure*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / ultrastructure*
  • Structure-Activity Relationship
  • Sus scrofa
  • Tubulin / genetics
  • Tubulin / metabolism
  • Tubulin / ultrastructure*


  • BIM1 protein, S cerevisiae
  • Cell Cycle Proteins
  • Microtubule Proteins
  • Saccharomyces cerevisiae Proteins
  • Tubulin
  • Guanosine Triphosphate