PHD Finger

**Semantic type:** Amino Acid Sequence

**Definition:** A C4HC3 zinc-finger-like motif, the PHD finger is found in nuclear proteins thought involved in chromatin-mediated transcriptional regulation. Single or multiple fingers are found. A specific function is not yet known, but it could be involved in protein-protein interactions important for assembly/activity of multi-component transcriptional regulatory complexes. In CBP it is an integral part of the acetyltransferase enzymatic core domain and contributes to CBP transcriptional activity. PHD fingers fold into an interleaved Zn-finger chelating two Zn ions in an atypical cross-braced conformation also shared by the FYVE and RING fingers; the zinc sites are located at opposite ends of a beta-sheet. Surrounding loops vary significantly in length and sequence between these three domains. (NCI)

**Synonyms:** - C4HC3 Zinc Finger - PHD Finger Domain - PHD Finger Motif - PHD-Finger - Plant Homeodomain (PHD) Type Zinc Finger