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6wg4

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Crystal structure of human SMC1-SMC3 hinge domain heterodimer in south-open conformation

Structural highlights

6wg4 is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.31Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

SMC1A_HUMAN Cornelia de Lange syndrome;Wiedemann-Steiner syndrome. The disease is caused by mutations affecting the gene represented in this entry.

Function

SMC1A_HUMAN Involved in chromosome cohesion during cell cycle and in DNA repair. Central component of cohesin complex. 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 anaphase, the complex is cleaved and dissociates from chromatin, allowing sister chromatids to segregate. The cohesin complex may also play a role in spindle pole assembly during mitosis. Involved in DNA repair via its interaction with BRCA1 and its related phosphorylation by ATM, or via its phosphorylation by ATR. Works as a downstream effector both in the ATM/NBS1 branch and in the ATR/MSH2 branch of S-phase checkpoint.^[1]

Publication Abstract from PubMed

As a ring-shaped ATPase machine, cohesin organizes the eukaryotic genome by extruding DNA loops and mediates sister-chromatid cohesion by topologically entrapping DNA. How cohesin executes these fundamental DNA transactions is not understood. Using cryo-electron microscopy, we determine the structure of human cohesin bound to its loader NIPBL and DNA at medium resolution. Cohesin and NIPBL interact extensively and together form a central tunnel to entrap a 72-base pair DNA. NIPBL and DNA promote the engagement of cohesin's ATPase head domains and ATP binding. The hinge domains of cohesin adopt an "open washer" conformation and dock onto the STAG1 subunit. Our structure explains the synergistic activation of cohesin by NIPBL and DNA, and provides insight into DNA entrapment by cohesin.

Cryo-EM structure of the human cohesin-NIPBL-DNA complex.,Shi Z, Gao H, Bai XC, Yu H Science. 2020 May 14. pii: science.abb0981. doi: 10.1126/science.abb0981. PMID:32409525^[2]

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

References

↑ Yazdi PT, Wang Y, Zhao S, Patel N, Lee EY, Qin J. SMC1 is a downstream effector in the ATM/NBS1 branch of the human S-phase checkpoint. Genes Dev. 2002 Mar 1;16(5):571-82. PMID:11877377 doi:http://dx.doi.org/10.1101/gad.970702
↑ Shi Z, Gao H, Bai XC, Yu H. Cryo-EM structure of the human cohesin-NIPBL-DNA complex. Science. 2020 May 14. pii: science.abb0981. doi: 10.1126/science.abb0981. PMID:32409525 doi:http://dx.doi.org/10.1126/science.abb0981