PHD finger 2 found in polycomb repressive complex 2 (PRC2)-associated polycomb-like (PCL) family proteins MTF2, PHF19, and similar proteins
The PCL family includes PHD finger protein1 (PHF1) and its homologs metal-response element-binding transcription factor 2 (MTF2/PCL2) and PHF19/PCL3, which are accessory components of the Polycomb repressive complex 2 (PRC2) core complex and all contain an N-terminal Tudor domain followed by two plant homeodomain (PHD) fingers, and a C-terminal MTF2 domain. PCL proteins specifically recognize tri-methylated H3K36 (H3K36me3) through their N-terminal Tudor domains. The interaction between their Tudor domains and H3K36me3 is critical for both the targeting and spreading of PRC2 into active chromatin regions and for the maintenance of optimal repression of poised developmental genes where PCL proteins, H3K36me3, and H3K27me3 coexist. Moreover, unlike other PHD finger-containing proteins, the first PHD finger of PCL proteins do not display histone H3K4 binding affinity and they do not affect the Tudor domain binding to histones. This model corresponds to the second PHD finger.
Jiyao W et al.(2023). "The conserved domain database in 2023.",