Tudor domain found in tumor suppressor TP53-binding protein 1 (53BP1) and similar proteins
53BP1, also called p53-binding protein 1 (p53BP1), is a double-strand break (DSB) repair protein involved in response to DNA damage, telomere dynamics, and class-switch recombination (CSR) during antibody genesis. It plays a key role in the repair of DSBs in response to DNA damage by promoting non-homologous end joining (NHEJ)-mediated repair of DSBs and specifically counteracting the function of the homologous recombination (HR) repair protein BRCA1. It is recruited to DSB sites by recognizing and binding histone H2A monoubiquitinated at 'Lys-15' (H2AK15Ub) and histone H4 dimethylated at 'Lys-20' (H4K20me2), two histone marks that are present at DSB sites. 53BP1 contains one Tudor domain. The Tudor domain binds to proteins with dimethylated arginine or lysine residues, and may also bind methylated histone tails to facilitate protein-protein interactions.