Cohesin is the protein complex responsible for binding the sister chromatids during mitosis through the G2 phase and into mitosis phase. It is a multi-subunit complex called which contains four core subunits: Smc1 and Smc3, which are members of the structural maintenance of chromosomes (SMC) protein family, and two non-SMC subunits, Scc1 (also called Mcd1) which is a member of the kleisin family, and Scc3. At metaphase, most cohesin is removed, except for some at the centromere. At Anaphase, securin, an inhibitory subunit of separase, is hydrolyzed. Separase hydrolyzes the remaining cohesin. In a classical experiment by covalently linking Cohesin's subunits which form a tripartite ring structure, Scc1, Smc1 and Smc3, it was demonstrated that that cohesin rings concatenate individual sister minichromosome DNA molecules.

References

See also

• SMC protein

External links

• Michaelis C, Ciosk R, Nasmyth K (1997). "Cohesins: chromosomal proteins that prevent premature separation of sister chromatids". Cell 91 (1): 35–45.
• Guacci V, Koshland D, Strunnikov A (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.
• Tóth A, Ciosk R, Uhlmann F, Galova M, Schleiffer A, Nasmyth K (1999). "Yeast cohesin complex requires a conserved protein, Eco1p(Ctf7), to establish cohesion between sister chromatids during DNA replication". Genes Dev. 13 (3): 320–33.
• Uhlmann F, Lottspeich F, Nasmyth K (1999). "Sister-chromatid separation at anaphase onset is promoted by cleavage of the cohesin subunit Scc1". Nature 400 (6739): 37–42.