Most agents that generate breaks in DNA leave 'dirty ends' that cannot be joined immediately; instead, intervening steps are required to restore the integrity of nucleotides at the break. Here it is shown that the non-homologous end joining pathway requires a 5′-dRP/AP lyase activity to remove abasic sites at double-strand breaks. Surprisingly, this activity is catalysed by the Ku70 protein, which, together with its partner Ku86, had been thought only to recognize broken DNA ends and to recruit other factors that process ends.
- Steven A. Roberts
- Natasha Strande
- Dale A. Ramsden
