HMTase assay performed with various concentrations of S -adenosyl-methionine (SAM) (24, 12, 6, 3 and 1.5 µM on the left gel and 6, 3 and 1.5 µM on the right), using 0.6 µM wild-type or mutant PRC2 complexes. 12 µM histone H3 substrates were used in the left panel and chromatinized DNA with the sequence of a polycomb target gene (naïve chromatin) was used in the right panel (0.645 µM chromatin used, determined based on the NCP molar equivalent). Three independent replicates were carried out on different days with similar results.
