Figure 1.

Structure, loading and repositioning of SMC complexes in budding yeast. (a) Schematic representation of cohesin, condensin and Smc5/6. Subunits are identified using the Saccharomyces cerevisiae nomenclature. The ring-and rod-like shapes of cohesin and condensin are based on electron micrographs. (b) Cohesin and condensin are both loaded by Scc2/4 (purple) at sites bound by the entire RNA polymerase III transcriptional apparatus (blue) or at sites bound by TFIIIC alone. Subsequently, cohesin moves to distant locations, embracing DNA and holding the newly replicated sister chromatids together from S phase until mitosis. Condensin stays in contact with the loading sites, bringing together distant TFIIIC sites.