Skip to main content
. 2023 Dec 22;9(51):eadj8198. doi: 10.1126/sciadv.adj8198

Fig. 1. H3K27 methylation by PRC2.

Fig. 1.

(A) The schematic overview. PRC2 methylates H3K27 in two modes: by hit-and-run, which leads to bulk dimethylation (light blue circles) and trimethylation (dark blue circles), and by being bound to PREs. The latter leads to high levels of H3K27me3. PREs also bind PRC1, which interacts with H3K27me3 and stabilizes contacts between a PRE-bound PRC2 and methylated chromatin. (B) An example of H3K27me3 profile around a PRE. The PRE (red box) is marked by strong ChIP-seq signal for the PRC2 subunit E(z). The blue box marks a region significantly enriched by H3K27me3 ChIP (39) [corresponds to the shaded part in (A)]. The scale is in dm3 genome release coordinates. (C) Formal representation of the H3K27 methylation process. Each nucleosome has two H3K27 positions that can have zero to three methyl groups attached. In vitro measurements indicate that the probability of adding a methyl group decreases for each methyl group already attached (23, 26).