Extended PHD finger found in retinoic acid-induced protein 1 (RAI1), transcription factor 20 (TCF-20) and similar proteins
The extended plant homeodomain (ePHD) zinc finger is characterized as Cys2HisCys5HisCys2His. This model includes the C-terminal ePHD/ADD (ATRX-DNMT3-DNMT3L) domain of RAI1 and TCF-20. RAI1, a homolog of stromelysin-1 PDGF (platelet-derived growth factor)-responsive element-binding protein (SPBP, also termed TCF-20), is a chromatin-binding protein implicated in the regulation of gene expression. TCF-20 is involved in transcriptional activation of the MMP3 (matrix metalloprotease 3) promoter. It also functions as a transcriptional co-regulator that enhances or represses the transcriptional activity of certain transcription factors/cofactors, such as specificity protein 1 (Sp1), E twenty-six 1 (Ets1), paired box protein 6 (Pax6), small nuclear RING-finger (SNURF)/RNF4, c-Jun, androgen receptor (AR) and estrogen receptor alpha (ERalpha). Both RAI1 and TCF-20 are strongly enriched in chromatin in interphase HeLa cells, and display low nuclear mobility, and have been implicated in Smith-Magenis syndrome and Potocki-Lupski syndrome.
Conserved feature residue pattern:C C H C C C C C H C C H
Evidence:
Comment:based on the structure evidence that human Borjeson-Forssman-Lehmann syndrome-associated protein PHF6 (PDB 4NN2) binds three Zn2+ ions through its ePHD finger
Comment:The extended PHD finger is characterized by Cys2HisCys5HisCys2His.
Jiyao W et al.(2023). "The conserved domain database in 2023.",