Fig. 1From: Therapeutic potential of inhibiting histone 3 lysine 27 demethylases: a review of the literatureTrimethyl H3K27 constitutes a repressive epigenetic mark of gene expression. When trimethylated at lysine 27 (K27) within its N terminus, histone 3 (H3) is intimately associated with inactive gene promoter regions, where the binding of RNA polymerase II (RNAPII) and transcription factors (TFs) is hampered. Trimethylation of H3K27 is unique in that it is exclusively catalysed by the H3K27-specific methyltransferase, enhancer of zeste homologue 2 (EZH2), a catalytic component of the polycomb repressive complex 2 (PRC2). Demethylation of H3K27, namely by the H3K27-specific lysine demethylases 6A (KDM6A) and 6B (KDM6B), serves to activate gene transcription by permitting the binding of RNAPII and TFs to promoter regions. This figure was created in BioRender.comBack to article page