The Cohesin Ring Concatenates Sister DNA Molecules

Nature. 2008 Jul 17;454(7202):297-301. doi: 10.1038/nature07098. Epub 2008 Jul 2.

Abstract

Sister chromatid cohesion, which is essential for mitosis, is mediated by a multi-subunit protein complex called cohesin. Cohesin's Scc1, Smc1 and Smc3 subunits form a tripartite ring structure, and it has been proposed that cohesin holds sister DNA molecules together by trapping them inside its ring. To test this, we used site-specific crosslinking to create chemical connections at the three interfaces between the three constituent polypeptides of the ring, thereby creating covalently closed cohesin rings. As predicted by the ring entrapment model, this procedure produced dimeric DNA-cohesin structures that are resistant to protein denaturation. We conclude that cohesin rings concatenate individual sister minichromosome DNA molecules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / metabolism*
  • Chromatids / metabolism*
  • Chromosomal Proteins, Non-Histone / chemistry
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Chromosomes, Fungal / metabolism*
  • DNA, Concatenated / metabolism*
  • DNA, Fungal / metabolism*
  • Protein Structure, Quaternary / drug effects
  • Protein Subunits / metabolism
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Sodium Dodecyl Sulfate / pharmacology

Substances

  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA, Concatenated
  • DNA, Fungal
  • Protein Subunits
  • Saccharomyces cerevisiae Proteins
  • cohesins
  • Sodium Dodecyl Sulfate

Associated data

  • PDB/1GXL