PHD finger found in PHD finger protein 7 (PHF7) and G2/M phase-specific E3 ubiquitin-protein ligase (G2E3)
PHF7, also termed testis development protein NYD-SP6, is a testis-specific plant homeodomain (PHD) finger-containing protein that associates with chromatin and binds histone H3 N-terminal tails with a preference for dimethyl lysine 4 (H3K4me2). It may play an important role in stimulating transcription involved in testicular development and/or spermatogenesis. PHF7 contains a canonical Cys4HisCys3 PHD finger and a non-canonical extended PHD (ePHD) finger, Cys2HisCys5HisCys2His, both of which may be involved in activating transcriptional regulation. G2E3 is a dual function ubiquitin ligase (E3) that may play a possible role in cell cycle regulation and the cellular response to DNA damage. It is essential for prevention of apoptosis in early embryogenesis. It is also a nucleo-cytoplasmic shuttling protein with DNA damage responsive localization. G2E3 contains two distinct RING-like ubiquitin ligase domains that catalyze lysine 48-linked polyubiquitination, and a C-terminal catalytic HECT domain that plays an important role in ubiquitin ligase activity and in the dynamic subcellular localization of the protein. The RING-like ubiquitin ligase domains consist of a PHD finger and an ePHD finger. This model corresponds to the Cys4HisCys3 canonical PHD finger.