Fig. 1: Biochemical and structural analysis of the DNMT1 BAH1–H4K20me3 interaction.
From: DNMT1 reads heterochromatic H4K20me3 to reinforce LINE-1 DNA methylation
a Domain architecture of human DNMT1 (hDNMT1), with individual domains delimited by residues numbers. b Histone peptide array analysis of the interactions between hDNMT1728–1600 and histone peptides. c Peptide pull-down analysis of the interactions of hDNMT1728–1600 with different H4K20me peptides. The experiment was repeated three times with consistent results. d ITC-binding assays for hDNMT1BAH1, titrated with different H4K20me peptides. e Peptide pull-down analysis of the interactions between hDNMT1BAH1 and different tri-methylated histone peptides. The experiment was repeated three times with consistent results. f Crystal structure of bDNMT1BAH1 (light pink) and H414–25K20me3 peptide (yellow), with the H4K20me3-binding pocket shown in the expanded view (boxed). The last two β-strands, which were domain-swapped during crystallization, are colored in salmon. The zinc ion is shown as a purple sphere. g Close-up view of the intermolecular interactions between bDNMT1BAH1 and the H414–25K20me3 peptide. The equivalent pocket residues in hDNMT1BAH1 are labeled in parentheses in (f, g). The hydrogen bonds are shown as dashed lines. *The side chain of H4 D24, except for the Cβ atom, is untraceable. h Kd values of hDNMT1BAH1 mutants and H414–25K20me3 peptides, derived from the ITC binding assays. NDB, no detectable binding. Source data are provided as a Source Data file.
