A physical assay for sister chromatid cohesion in vitro.
Cohesion between sister chromatids depends on a multiprotein complex called cohesin that has been proposed to hold sister DNAs together by trapping them inside a large tripartite ring. Sister chromatid cohesion has hitherto only been detected by using cytological methods in living cells. We show here that cohesion between the sister DNAs of circular minichromosomes established in vivo can be detected in vitro by velocity gradient sedimentation and agarose-gel electrophoresis. This ex vivo cohesion does not depend on intercatenation of sister DNAs but is destroyed by cleavage of cohesin's Scc1 subunit or minichromosome linearization. These data represent the best evidence so far that the cohesin ring physically holds sister DNAs together and are consistent with the notion that it does so by using a topological principle involving the trapping DNAs inside its ring.
Ivanov
Dmitri
D
Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria.
Nasmyth
Kim
K
Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria. Electronic address: kim.nasmyth@bioch.ox.ac.uk.
D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism; D000268:Adhesiveness; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002842:Chromatids / Q000235:genetics / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone; D004270:DNA, Circular / Q000235:genetics / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D012854:Sister Chromatid Exchange
D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004270:DNA, Circular; D004271:DNA, Fungal; C490529:MCD1 protein, S cerevisiae; D009687:Nuclear Proteins; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; D000123:Acetyltransferases; C118076:ECO1 protein, S cerevisiae