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Publication Abstract from PubMed

Genome regulation requires control of chromosome organization by SMC-kleisin complexes. The cohesin complex contains the Smc1 and Smc3 subunits that associate with the kleisin Scc1 to form a ring-shaped complex that can topologically engage chromatin to regulate chromatin structure. Release from chromatin involves opening of the ring at the Smc3-Scc1 interface in a reaction that is controlled by acetylation and engagement of the Smc ATPase head domains. To understand the underlying molecular mechanisms, we have determined the 3.2-A resolution cryo-electron microscopy structure of the ATPgammaS-bound, heterotrimeric cohesin ATPase head module and the 2.1-A resolution crystal structure of a nucleotide-free Smc1-Scc1 subcomplex from Saccharomyces cerevisiae and Chaetomium thermophilium. We found that ATP-binding and Smc1-Smc3 heterodimerization promote conformational changes within the ATPase that are transmitted to the Smc coiled-coil domains. Remodeling of the coiled-coil domain of Smc3 abrogates the binding surface for Scc1, thus leading to ring opening at the Smc3-Scc1 interface.

The structure of the cohesin ATPase elucidates the mechanism of SMC-kleisin ring opening.,Muir KW, Li Y, Weis F, Panne D Nat Struct Mol Biol. 2020 Feb 17. pii: 10.1038/s41594-020-0379-7. doi:, 10.1038/s41594-020-0379-7. PMID:32066964^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.