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From Proteopedia
Crystal structure of the S. pombe condensin Cnd3-Cnd2 subcomplex
Structural highlights
Function[CND3_SCHPO] Regulatory subunit of the condensin complex, a complex required for conversion of interphase chromatin into mitotic-like condense chromosomes. The condensin complex probably introduces positive supercoils into relaxed DNA in the presence of type I topoisomerases and converts nicked DNA into positive knotted forms in the presence of type II topoisomerases. The condensin complex probably also plays a role during interphase.[1] [CND2_SCHPO] Regulatory subunit of the condensin complex, a complex required for conversion of interphase chromatin into mitotic-like condense chromosomes. The condensin complex probably introduces positive supercoils into relaxed DNA in the presence of type I topoisomerases and converts nicked DNA into positive knotted forms in the presence of type II topoisomerases. The condensin complex probably also plays a role during interphase in processes such as DNA repair.[2] [3] Publication Abstract from PubMedCondensin protein complexes coordinate the formation of mitotic chromosomes and thereby ensure the successful segregation of replicated genomes. Insights into how condensin complexes bind to chromosomes and alter their topology are essential for understanding the molecular principles behind the large-scale chromatin rearrangements that take place during cell divisions. Here, we identify a direct DNA-binding site in the eukaryotic condensin complex, which is formed by its Ycg1Cnd3 HEAT-repeat and Brn1Cnd2 kleisin subunits. DNA co-crystal structures reveal a conserved, positively charged groove that accommodates the DNA double helix. A peptide loop of the kleisin subunit encircles the bound DNA and, like a safety belt, prevents its dissociation. Firm closure of the kleisin loop around DNA is essential for the association of condensin complexes with chromosomes and their DNA-stimulated ATPase activity. Our data suggest a sophisticated molecular basis for anchoring condensin complexes to chromosomes that enables the formation of large-sized chromatin loops. Structural Basis for a Safety-Belt Mechanism That Anchors Condensin to Chromosomes.,Kschonsak M, Merkel F, Bisht S, Metz J, Rybin V, Hassler M, Haering CH Cell. 2017 Oct 4. pii: S0092-8674(17)31057-7. doi: 10.1016/j.cell.2017.09.008. PMID:28988770[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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