6qpq
From Proteopedia
The structure of the cohesin head module elucidates the mechanism of ring opening
Structural highlights
Function[SCC1_YEAST] Cleavable component of the cohesin complex involved in chromosome cohesion during cell cycle. The cohesin complex is required for the cohesion of sister chromatids after DNA replication. The cohesin complex apparently forms a large proteinaceous ring within which sister chromatids can be trapped. At metaphase-anaphase transition, this protein is cleaved by ESP1 and dissociates from chromatin, allowing sister chromatids to segregate.[1] [2] [3] [4] Publication Abstract from PubMedGenome 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[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Baker's yeast | Chatd | Large Structures | Li, Y | Muir, K W | Panne, D | Cell cycle | Cell division | Cohesin | Genome regulation | Kleisin | Sister chromatid cohesion | Smc
