The RecQ helicase–topoisomerase III–Rmi1 complex: a DNA structure-specific ‘dissolvasome’?

RecQ helicases, together with topoisomerase III and Rmi1 family proteins, form an evolutionarily conserved complex that is essential for the maintenance of genome integrity. This complex, which we term RTR, is capable of, or has been implicated in, the processing of a diverse array of DNA structures, and we propose here that it functions in a coordinated fashion as a DNA structure-specific ‘dissolvasome’. Little is known about how the RTR complex might be regulated or targeted to various DNA structures in vivo. Recent findings indicate that the components of the RTR complex might activate the cell cycle checkpoint machinery as well as be a target of checkpoint kinases, suggesting that these events are crucial to ensure faithful DNA replication and chromosome segregation.