DNA helicase that acts as a tension sensor that associates with catenated DNA which is stretched under tension until it is resolved during anaphase. Functions as ATP-dependent DNA translocase. Can promote Holliday junction branch migration (in vitro). ATP + H2O = ADP + H(+) + phosphate Localizes to kinetochores, inner centromeres and thin threads connecting separating chromosomes even during anaphase. Belongs to the SNF2/RAD54 helicase family.