Involved in the DNA damage response pathway by contributing to the maintenance of chromatin architecture. Recruited to the vicinity of DNA breaks by TP53BP1 and plays an accessory role to facilitate damage-induced chromatin changes and promoting chromatin relaxation. Required for efficient DNA repair and cell survival following DNA damage (By similarity). Interacts with TP53BP1 (via BRCT domain); the interaction is not dependent on its phosphorylation status. Binds nucleosomes. Interacts with trimethylated 'Lys-36' of histone H3 (H3K36me3) (in vitro) (By similarity). Recruited to DNA damage sites via its interaction with the BRCT domain of TP53BP1. The PWWP domain mediates the interaction with nucleosomes. Belongs to the PWWP3A family. Truncated N-terminus. Intron retention. This sequence is incomplete at the 5'-end.