Fig. 4. MRK-740 binding is unique among methyltransferase inhibitors.

a Atoms tallied at the interface (distance < 4 Å) between SAM or SAH and small molecule inhibitors. Rossmann-type methyltransferases targeting nitrogen or oxygen are indicated in blue or orange, respectively. The tallied atoms (red) at the interface between SAM or SAH (teal) and small molecule inhibitors (pink) are shown for (b) PRDM9 with MRK-470, (c) SUV420H1 with 9ZY, (d) SETD7 with (R)-PFI-2, (e) SMYD2 with AZ506, (f) HNMT with Quinacrine, (g) PRMT5 with EPZ015666, and (h) COMT with a Mg²⁺ cation and 43J. The post-SET helices are indicated in purple. PDB accession codes: 6NM4, 5WBV, 4JLG, 5KJN, 1JQE, 4 × 61 and 4XUE, respectively. Data are from Supplementary Table 2.