Fig. 4. Nuclease contamination cannot explain RNA–DNA hybrid formation by PRC2.
a Scheme of experiment to test whether PRC2 generate a long ssDNA filament. Linear DNA was incubated with PRC2 or exonuclease III and purified. SSB protein was added to pre-treated DNA and samples were visualized by electron microscopy. b, c Representative EM pictures of DNA pre-treated with Exonuclease III (b) or with PRC2 (c). Arrows indicate DNA with (b) or without (c) SSB coating. d Scheme of experiment to test whether pre-incubation of DNA with PRC2 allows RNA–DNA hybrid formation in the absence of PRC2.is sufficient. e, f Representative gel (e) and quantification (f) of strand exchange reactions using DNA that was pre-treated with PRC2 (400 nM) as the substrate. n = 3. Graph shows the mean +/− S.E.M. Source data are provided in Source Data file.