The p53-binding protein 1 (53BP1) regulates the choice of the DNA double-strand break repair pathway. Here the authors present the crystal structure of Tudor-interacting repair regulator (TIRR) bound to the 53BP1 tandem Tudor ___domain, which reveals how TIRR blocks H4K20me2 binding to 53BP1 Tudor and functionally differs from its paralog Nudt16.
- Yaxin Dai
- Aili Zhang
- Zheng Zhou