Putting PHDs to work: PHF11 clears the way for EXO1 in double-strand break repair.

In this issue of Genes & Development, Gong and colleagues (pp. 46-58) bring to light a functional role for plant homeodomain finger 11 (PHF11) in 5' end resection at DNA double-strand breaks (DSBs). Using the proteomics of isolated chromatin segments (PICh) technique to purify deprotected telomeres, PHF11 was enriched as cells mounted a DNA damage response (DDR) against exposed chromosome ends. The study reveals interactions between PHF11 and multiple DNA repair proteins and suggests that PHF11 mediates 5' end resection by negotiating RPA-coated DNA repair intermediates. This finding provides a novel context for mediator-catalyzed RPA exchanges during the multistep process of homologous recombination (HR).