Condensin I and topo IIα are essential for mitotic chromosome assembly. Here, the authors identify a cooperative mechanism of DNA compaction in which condensin I–mediated loop extrusion is coupled with topo IIα–mediated strand passage. This process depends on the C-terminal domain of topo IIα.
- Yuko Tsubota
- Keishi Shintomi
- Tomoko Nishiyama
