Structure and function of cohesin's Scc3/SA regulatory subunit

FEBS Lett. 2014 Oct 16;588(20):3692-702. doi: 10.1016/j.febslet.2014.08.015. Epub 2014 Aug 27.


Sister chromatid cohesion involves entrapment of sister DNAs by a cohesin ring created through association of a kleisin subunit (Scc1) with ATPase heads of Smc1/Smc3 heterodimers. Cohesin's association with chromatin involves subunits recruited by Scc1: Wapl, Pds5, and Scc3/SA, in addition to Scc2/4 loading complex. Unlike Pds5, Wapl, and Scc2/4, Scc3s are encoded by all eukaryotic genomes. Here, a crystal structure of Scc3 reveals a hook-shaped protein composed of tandem α helices. Its N-terminal domain contains a conserved and essential surface (CES) present even in organisms lacking Pds5, Wapl, and Scc2/4, while its C-terminal domain binds a section of the kleisin Scc1. Scc3 turns over in G2/M while maintaining cohesin's association with chromosomes and it promotes de-acetylation of Smc3 upon Scc1 cleavage.

Keywords: Cohesin complex; Eco1 acetylation; Maintenance of cohesion; Releasing activity; SA/STAG domain; Scc3; Sister chromatid separation; Smc proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Amino Acid Sequence
  • Binding Sites
  • Cell Cycle Proteins / chemistry*
  • Cell Cycle Proteins / metabolism*
  • Chromosomal Proteins, Non-Histone / chemistry
  • Chromosomal Proteins, Non-Histone / metabolism*
  • G2 Phase Cell Cycle Checkpoints
  • Molecular Sequence Data
  • Protein Subunits / chemistry
  • Protein Subunits / metabolism
  • Proteolysis
  • Saccharomyces cerevisiae / chemistry*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology
  • Saccharomyces cerevisiae Proteins / chemistry*
  • Saccharomyces cerevisiae Proteins / metabolism*


  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • IRR1 protein, S cerevisiae
  • MCD1 protein, S cerevisiae
  • Protein Subunits
  • SMC3 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins