This domain family is found in eukaryotes, and is approximately 150 amino acids in length. This family is part of a non-SMC subunit of condensin II which is involved in maintenance of the structural integrity of chromosomes. Condensin II is made up of SMC (structural maintenance of chromosomes) and non-SMC subunits. The non-SMC subunits bind to the catalytic ends of the SMC subunit dimer. The condensin holocomplex is able to introduce superhelical tension into DNA in an ATP hydrolysis- dependent manner, resulting in the formation of positive supercoils in the presence of topoisomerase I and of positive knots in the presence of topoisomerase II.

1: Differential contributions of condensin I and condensin II to mitotic chromosome architecture in vertebrate cells. Ono T, Losada A, Hirano M, Myers MP, Neuwald AF, Hirano T; Cell. 2003;115:109-121. PMID:14532007