Structural basis of nucleosomal H4K20 recognition and methylation by SUV420H1 methyltransferase

Here we report the cryo-electron microscopy (cryo-EM) structures of SUV420H1 associated with canonical nucleosome core particles (NCPs) or H2AZ containing NCPs. We find that SUV420H1 shows conformational change after bound to a nucleosome and make extensive site-specific contacts with histone and DNA regions, thus enabling H4K20 insertion for catalysis specifically. Through in vivo functional analysis, we validated special residues of SUV420H1 that are critical for its catalytic activity and function in chromatin state regulation.Thus, our study provides molecular insights into the nucleosome-based recognition and histone- methylation mechanisms of SUV420H1. We ectopically expressed SUV420H1(Aa1-550) or SUV420H1(Aa1-550) with a single K258E, S255F, S283L, Y349A, R352A or R357H mutation in a HeLa SUV420H1-/- cell line, and performed ATAC-seq under each condition. Please note that each processed data file was generated from both replicates and is linked to the corresponding rep1 sample records