PHD finger found in bromodomain and PHD finger-containing protein 1 (BRPF1) and similar proteins
BRPF1, also termed peregrin or protein Br140, is a multi-domain protein that binds histones, mediates monocytic leukemic zinc-finger protein (MOZ)-dependent histone acetylation, and is required for Hox gene expression and segmental identity. It is a close partner of the MOZ histone acetyltransferase (HAT) complex and a novel Trithorax group (TrxG) member with a central role during development. BRPF1 is primarily a nuclear protein that has a broad tissue distribution and is abundant in testes and spermatogonia. It contains a canonical Cys4HisCys3 plant homeodomain (PHD) zinc finger followed by a non-canonical extended PHD (ePHD) finger, Cys2HisCys5HisCys2His, a bromodomain and a proline-tryptophan-tryptophan-proline (PWWP) domain. PHD and ePHD fingers both bind to lysine 4 of histone H3 (K4H3), bromodomains interact with acetylated lysines on N-terminal tails of histones and other proteins, and PWWP domains show histone-binding and chromatin association properties. BRPF1 may be involved in chromatin remodeling. This model corresponds to the canonical Cys4HisCys3 PHD finger.