The structure and function of SMC and kleisin complexes
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Updated: Aug 5, 2026

High-Resolution Complexome Profiling by Cryoslicing BN-MS Analysis
Published on: October 15, 2019
Kim Nasmyth1, Christian H Haering
1Institute of Molecular Pathology, A-1030 Vienna, Austria. knasmyth@imp.univie.ac.at
Abstract:
Protein complexes consisting of structural maintenance of chromosomes (SMC) and kleisin subunits are crucial for the faithful segregation of chromosomes during cell proliferation in prokaryotes and eukaryotes. Two of the best-studied SMC complexes are cohesin and condensin. Cohesin is required to hold sister chromatids together, which allows their bio-orientation on the mitotic spindle. Cleavage of cohesin's kleisin subunit by the separase protease then triggers the movement of sister chromatids into opposite halves of the cell during anaphase. Condensin is required to organize mitotic chromosomes into coherent structures that prevent them from getting tangled up during segregation. Here we describe the discovery of SMC complexes and discuss recent advances in determining how members of this ancient protein family may function at a mechanistic level.
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