(A) Structure of the COMPASS eCM bound to a mononucleosome (PDB code 6UGM). The disordered H3 and H4 tails are shown in gold and blue, respectively, with the last observable amino acid indicated. Dotted lines indicate missing N-terminal amino acids. Spp1 (orange) suppressor of PRP protein 1. Swd3 (light blue), Set1 complex WD40 repeat protein 3. Swd1 (red), Set1 complex WD40 repeat protein 1. Set1 (green), SET domain protein 1. Bre2 (pink), brefeldin-A sensitivity protein 2. Sdc1-A/B (yellow), suppressor of CDC25 protein 1. (B) Western blots of the products from methylation assays with mononucleosome substrates containing wild-type (wt) H4 or H4K12su and the COMPASS eCM complex. Mono-, di-, and trimethylated states of H3K4 were detected by the indicated modification-specific antibodies. (C) Western blots of the products from methylation assays with mononucleosome substrates containing wt H4 or H4K12su and the COMPASS catalytic module. Mono-, di-, and trimethylated states of H3K4 were detected by the indicated modification-specific antibodies.
Figure 5—source data 1. Unedited western blot membranes for all western blot images shown in Figure 5.