Molecular architecture and connectivity of the budding yeast Mtw1 kinetochore complex

J Mol Biol. 2011 Jan 14;405(2):548-59. doi: 10.1016/j.jmb.2010.11.012. Epub 2010 Nov 12.

Abstract

Kinetochores are large multiprotein complexes that connect centromeres to spindle microtubules in all eukaryotes. Among the biochemically distinct kinetochore complexes, the conserved four-protein Mtw1 complex is a central part of the kinetochore in all organisms. Here we present the biochemical reconstitution and characterization of the budding yeast Mtw1 complex. Direct visualization by electron microscopy revealed an elongated bilobed structure with a 25-nm-long axis. The complex can be assembled from two stable heterodimers consisting of Mtw1p-Nnf1p and Dsn1p-Nsl1p, and it interacts directly with the microtubule-binding Ndc80 kinetochore complex via the centromere-proximal Spc24/Spc25 head domain. In addition, we have reconstituted a partial Ctf19 complex and show that it directly associates with the Mtw1 complex in vitro. Ndc80 and Ctf19 complexes do not compete for binding to the Mtw1 complex, suggesting that Mtw1 can bridge the microtubule-binding components of the kinetochore to the inner centromere.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle Proteins / chemistry*
  • Cell Cycle Proteins / metabolism*
  • Chromosomal Proteins, Non-Histone / chemistry
  • Chromosomal Proteins, Non-Histone / metabolism
  • Cytoskeletal Proteins / chemistry
  • Cytoskeletal Proteins / metabolism
  • Kinetochores / chemistry*
  • Kinetochores / metabolism*
  • Microscopy, Electron
  • Microtubules / metabolism
  • Multiprotein Complexes / chemistry*
  • Multiprotein Complexes / metabolism*
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / metabolism
  • Protein Multimerization
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / chemistry*
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • CTF19 protein, S cerevisiae
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Cytoskeletal Proteins
  • Dsn1 protein, S cerevisiae
  • MTW1 protein, S cerevisiae
  • Multiprotein Complexes
  • NDC80 protein, S cerevisiae
  • NNF1 protein, S cerevisiae
  • Nsl1 protein, S cerevisiae
  • Nuclear Proteins
  • Saccharomyces cerevisiae Proteins
  • Spc24 protein, S cerevisiae
  • Spc25 protein, S cerevisiae