Building and breaking bridges between sister chromatids

Bioessays. 2003 Dec;25(12):1178-91. doi: 10.1002/bies.10361.


Eukaryotic chromosomes undergo dramatic changes and movements during mitosis. These include the individualization and compaction of the two copies of replicated chromosomes (the sister chromatids) and their subsequent segregation to the daughter cells. Two multisubunit protein complexes termed 'cohesin' and 'condensin', both composed of SMC (Structural Maintenance of Chromosomes) and kleisin subunits, have emerged as crucial players in these processes. Cohesin is required for holding sister chromatids together whereas condensin, together with topoisomerase II, has an important role in organizing individual axes of sister chromatids prior to their segregation during anaphase. SMC and kleisin complexes also regulate the compaction and segregation of bacterial nucleoids. New research suggests that these ancient regulators of chromosome structure might function as topological devices that trap chromosomal DNA between 50 nm long coiled coils.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / physiology
  • Anaphase
  • Animals
  • Bacterial Proteins / physiology
  • Cell Cycle
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / physiology
  • Chromatids / ultrastructure*
  • Chromosomal Proteins, Non-Histone
  • DNA Topoisomerases, Type II / physiology
  • DNA-Binding Proteins / physiology
  • Endopeptidases / physiology
  • Fungal Proteins
  • Humans
  • Kinetochores / metabolism
  • Metaphase
  • Microtubules / metabolism
  • Mitosis*
  • Models, Biological
  • Models, Genetic
  • Models, Molecular
  • Multiprotein Complexes
  • Nuclear Proteins / chemistry
  • Phosphoproteins
  • Prophase
  • Protein Binding
  • Protein Structure, Tertiary
  • Saccharomyces cerevisiae Proteins
  • Separase


  • Bacterial Proteins
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Fungal Proteins
  • MCD1 protein, S cerevisiae
  • Multiprotein Complexes
  • Nuclear Proteins
  • Phosphoproteins
  • SMC protein, Bacteria
  • Saccharomyces cerevisiae Proteins
  • cohesins
  • condensin complexes
  • Endopeptidases
  • Separase
  • Adenosine Triphosphatases
  • DNA Topoisomerases, Type II