|PROSITE documentation PDOC50016 [for PROSITE entry PS50016]|
The Plant Homeodomain (PHD) type zinc finger (C4HC3)  is found in nuclear proteins thought to be involved in chromatin-mediated transcriptional regulation. The PHD finger motif is reminiscent of, but distinct from the C3HC4-type RING finger. A general function of the PHD finger is not yet known, but in the CREB-binding protein (CBP) it is an integral part of the enzymatic core of the acetyltransferase domain and is also a key contributor to the transcriptional activity of CBP.
The 3D structure of Williams-Beuren Syndrome transcription factor (see <PDB:1F62>) reveals that the PHD finger coordinates two atoms of zinc in a cross-braced manner . This atypical conformation is also shared by the FYVE (see <PDOC50178> and RING fingers (see <PDOC00449>). The two zinc sites are located at opposite ends of a short β-sheet. This feature is also shared by the RING finger and the FYVE domain, but the structure differ in the surrounding loops that vary significantly in length and sequence and could explain the wide variety of functions between these three domains.
Single or multiple PHD fingers are found in the following proteins:
The consensus pattern we developed start at the first cysteine and end at the last one, whereas the profile we developed spans the complete domain.Note:
The spacing between cysteines in the PHD finger is closely related to that in the RING finger. Discrimination between these two domains with either a pattern or a profile is therefore difficult, and some rare domains are recognized by both the RING and PHD descriptors.Expert(s) to contact by email:
May 2002 / First entry.
PROSITE methods (with tools and information) covered by this documentation:
|1||Authors||Aasland R. Gibson T.J. Stewart A.F.|
|Title||The PHD finger: implications for chromatin-mediated transcriptional regulation.|
|Source||Trends Biochem. Sci. 20:56-59(1995).|
|2||Authors||Pascual J. Martinez-Yamout M. Dyson H.J. Wright P.E.|
|Title||Structure of the PHD zinc finger from human Williams-Beuren syndrome transcription factor.|
|Source||J. Mol. Biol. 304:723-729(2000).|
|Title||Transcriptional activation of Drosophila homeotic genes from distant regulatory elements.|
|Source||Trends Genet. 9:75-79(1993).|
|Title||Mechanisms of heritable gene repression during development of Drosophila.|
|Source||Curr. Opin. Cell Biol. 5:999-1005(1993).|