RWD domain: a recurring module in kinetochore architecture shown by a Ctf19-Mcm21 complex structure

EMBO Rep. 2012 Mar 1;13(3):216-22. doi: 10.1038/embor.2012.1.


The proteins Ctf19, Okp1, Mcm21 and Ame1 are the components of COMA, a subassembly of budding-yeast kinetochores. We have determined the crystal structure of a conserved COMA subcomplex--the Ctf19-Mcm21 heterodimer--from Kluyveromyces lactis. Both proteins contain 'double-RWD' domains, which together form a Y-shaped framework with flexible N-terminal extensions. The kinetochore proteins Csm1, Spc24 and Spc25 have related single RWD domains, and Ctf19 and Mcm21 associate with pseudo-twofold symmetry analogous to that in the Csm1 homodimer and the Spc24-Spc25 heterodimer. The double-RWD domain core of the Ctf19-Mcm21 heterodimer is sufficient for association with Okp1-Ame1; the less conserved N-terminal regions may interact with components of a more extensive 'CTF19 complex'. Our structure shows the RWD domain to be a recurring module of kinetochore architecture that may be present in other kinetochore substructures. Like many eukaryotic molecular machines, kinetochores may have evolved from simpler assemblies by multiplication of a few ancestral modules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Cycle Proteins / chemistry*
  • Conserved Sequence
  • Cytoskeletal Proteins / chemistry*
  • Fungal Proteins / chemistry
  • Kinetochores / chemistry*
  • Kinetochores / metabolism
  • Models, Molecular
  • Protein Binding
  • Protein Interaction Domains and Motifs*
  • Protein Multimerization
  • Protein Structure, Secondary
  • Saccharomycetales / chemistry
  • Saccharomycetales / metabolism


  • Cell Cycle Proteins
  • Cytoskeletal Proteins
  • Fungal Proteins