Cohesin

Diagram of cohesin showing its four constituent protein subunits

Cohesin is a protein complex that mediates sister chromatid cohesion, homologous recombination, and DNA looping. Cohesin is formed of SMC3, SMC1, SCC1 and SCC3 (SA1 or SA2 in humans). Cohesin holds sister chromatids together after DNA replication until anaphase when removal of cohesin leads to separation of sister chromatids. The complex forms a ring-like structure and it is believed that sister chromatids are held together by entrapment inside the cohesin ring. Cohesin is a member of the SMC family of protein complexes which includes Condensin, MukBEF and SMC-ScpAB.

Cohesin was separately discovered in budding yeast (Saccharomyces cerevisiae) both by Douglas Koshland[1] and Kim Nasmyth in 1997.[2]

  1. ^ Guacci, V; Koshland, D; Strunnikov, A (3 October 1997). "A direct link between sister chromatid cohesion and chromosome condensation revealed through the analysis of MCD1 in S. cerevisiae". Cell. 91 (1): 47–57. doi:10.1016/s0092-8674(01)80008-8. PMC 2670185. PMID 9335334.
  2. ^ Michaelis, C; Ciosk, R; Nasmyth, K (3 October 1997). "Cohesins: chromosomal proteins that prevent premature separation of sister chromatids". Cell. 91 (1): 35–45. doi:10.1016/s0092-8674(01)80007-6. PMID 9335333. S2CID 18572651.