PHD finger found in proteins Jade-1, Jade-2, Jade-3, and similar proteins
This family includes proteins Jade-1 (PHF17), Jade-2 (PHF15), and Jade-3 (PHF16), each of which is required for ING4 and ING5 to associate with histone acetyltransferase (HAT) HBO1 and EAF6 to form a HBO1 complex that has a histone H4-specific acetyltransferase activity, a reduced activity toward histone H3, and is responsible for the bulk of histone H4 acetylation in vivo. This family also contains Drosophila melanogaster PHD finger protein rhinoceros (RNO). It is a novel plant homeodomain (PHD)-containing nuclear protein that may function as a transcription factor that antagonizes Ras signaling by regulating transcription of key EGFR/Ras pathway regulators in the Drosophila eye. All Jade proteins contain a canonical Cys4HisCys3 PHD finger followed by a non-canonical extended PHD (ePHD) finger, Cys2HisCys5HisCys2His, both of which are zinc-binding motifs. This model corresponds to the canonical Cys4HisCys3 PHD finger.