Intermolecular DNA interactions stimulated by the cohesin complex in vitro: Implications for sister chromatid cohesion

Losada, A., Hirano, T. (February 2001) Intermolecular DNA interactions stimulated by the cohesin complex in vitro: Implications for sister chromatid cohesion. Current Biology, 11 (4). pp. 268-272. ISSN 0960-9822

Abstract

The establishment of sister chromatid cohesion during S phase and its dissolution at the metaphase-anaphase transition are essential for the faithful segregation of chromosomes in mitosis [1-4], Recent studies in yeast genetics and Xenopus biochemistry have identified a large protein complex, cohesin, that plays a key role in sister chromatid cohesion [5-10]. The cohesin complex consists of a heterodimeric pair of SMC (structural maintenance of chromosomes) subunits and at least two non-SMC subunits. This structural organization is reminiscent of that of condensin, another major SMC protein complex that drives chromosome condensation in eukaryotic cells [11], Condensin has been shown to reconfigure and compact DNA in vitro by utilizing the energy of ATP hydrolysis [12], Very little is known, however, about how cohesin works at a mechanistic level. Here we report the first set of biochemical activities associated with an intact cohesin complex purified from HeLa cell extracts. The cohesin complex binds directly to double-stranded DNA and induces the formation of large protein-DNA aggregates. In the presence of topoisomerase II, cohesin stimulates intermolecular catenation of circular DNA molecules. This activity is in striking contrast to intramolecular knotting directed by condensin [13], Cohesin also increases the probability of intermolecular ligation of linear DNA molecules in the presence of DNA ligase, Our results are consistent with a model in which cohesin functions as an intermolecular DNA crosslinker and is part of the molecular "glue" that holds sister chromatids together [14].

Item Type: Paper
Uncontrolled Keywords: CHROMOSOME CONDENSATION 13S CONDENSIN STRUCTURAL MAINTENANCE PROTEIN COMPLEXES YEAST COHESIN IN-VITRO SEPARATION XENOPUS SMC IDENTIFICATION
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > chromatid
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > Chromatin dynamics
CSHL Authors:
Communities: CSHL labs > Hirano lab
Depositing User: Matt Covey
Date: February 2001
Date Deposited: 17 Jan 2014 21:37
Last Modified: 17 Jan 2014 21:37
Related URLs:
URI: https://repository.cshl.edu/id/eprint/29265

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