Sister chromatid cohesion through the lens of biochemical experiments.

Faithful chromosome segregation in eukaryotes relies on physical cohesion between newly duplicated sister chromatids. Cohesin is a ring-shaped ATPase assembly that mediates sister chromatid cohesion through its ability to topologically entrap DNA. Cohesin, assisted by several regulatory proteins, binds to DNA prior to DNA replication and then holds two sister DNAs together when it encounters the replication machinery. Cohesion establishment further requires cohesin acetylation, which confers near eternal stability on chromatin-bound cohesin until the onset of chromosome segregation. In addition to a wealth of experimental evidence from cellular studies, recent advances in reconstitution approaches are now beginning to unravel the biochemical properties of cohesin that underlie its function in sister chromatid cohesion. This review summarizes recent insights into the mechanism of cohesion establishment.