|450px|thumb|an interphase nucleus (left) and a set of mitotic chromosomes (right) from human tissue culture cells. bar, 10 Î¼m. condensins are large protein complexes that play a central role in chromosome assembly and segregation during mitosis and meiosis. == subunit composition == === eukaryotic condensins === 400px|thumb|subunit composition of condensin complexes many eukaryotic cells possess two different types of condensin complexes, known as condensin i and condensin ii, each of which is composed of five subunits. condensins i and ii share the same pair of core subunits, smc2 and smc4, both belonging to a large family of chromosomal atpases, known as smc proteins (smc stands for structural maintenance of chromosomes). each of the complexes contains a distinct set of non-smc regulatory subunits (a kleisin subunit and a pair of heat-repeat subunits). the nematode caenorhabditis elegans possesses a third complex (closely related to condensin i) that participates in chromosome-wide gene regulation, i.e., [[d
Cell_cycle Mitosis Proteins