Polycomb group (PcG) protein. Component of the PRC2/EED-EZH2 complex, which methylates 'Lys-9' (H3K9me) and 'Lys-27' (H3K27me) of histone H3, leading to transcriptional repression of the affected target gene. The PRC2/EED-EZH2 complex may also serve as a recruiting platform for DNA methyltransferases, thereby linking two epigenetic repression systems (By similarity). Genes repressed by the PRC2/EED-EZH2 complex include HOXA7, HOXB6 and HOXC8. Component of the PRC2 complex, which consists of the core subunits EED, EZH1 or EZH2, SUZ12, and RBBP4, and various combinations of accessory subunits including AEBP2, JARID2, PHF19, MTF2 and EPOP (PubMed:19026780, PubMed:20144788). Within the complex, interacts (via C2H2 zinc finger domain) with JARID2 and EPOP; JARID2 and EPOP compete for SUZ12 binding (By similarity). Also interacts with AEBP2 and PHF19 (By similarity). Forms a monomeric PRC2.2 (class 2) complex consisting of at least SUZ12, RBBP4, AEBP2 and JARID2 (By similarity). Forms a dimeric PRC2.1 (class 1, PRC-PCL) complex consisting of at least SUZ12, RBBP4, and PHF19 or MTF2; PHF19 and MTF2 stabilize the dimeric structure which enhances PRC2 interaction with chromatin (By similarity). The minimum components required for methyltransferase activity of the PRC2/EZH2 complex are EED, EZH2 and SUZ12 (By similarity). The PRC2 complex may also interact with DNMT1, DNMT3A, DNMT3B and PHF1 via the EZH2 subunit and with SIRT1 via the SUZ12 subunit. Interacts with WDR77 (PubMed:16712789). Interacts with histone H1. Interacts with CDYL (By similarity). Interacts with ARNTL/BMAL1 (PubMed:23970558). Interacts with EZHIP (via C-terminal region) (By similarity). Interacts with ARMC12 (By similarity). Localizes to the inactive X chromosome in trophoblast stem cells. Expressed in embryonic stem cells. Expression increases in prostate during prostate tumor development. Sumoylated, probably by PIAS2. Mice exhibit early embryonic lethality and defects in gastrulation accompanied by reduced methylation of 'Lys-27' of histone H3. Belongs to the VEFS (VRN2-EMF2-FIS2-SU(Z)12) family. Unknown reasons.