RYBP Is a K63-Ubiquitin-Chain-Binding Protein that Inhibits Homologous Recombination Repair

Ring1-YY1-binding protein (RYBP) is a member of the non-canonical polycomb repressive complex 1 (PRC1), and like other PRC1 members, it is best described as a transcriptional regulator. However, several PRC1 members were recently shown to function in DNA repair. Here, we report that RYBP preferentially binds K63-ubiquitin chains via its Npl4 zinc finger (NZF) domain. Since K63-linked ubiquitin chains are assembled at DNA double-strand breaks …