10.1021/acs.jmedchem.6b01244.s001 Kyle V. Butler Kyle V. Butler Anqi Ma Anqi Ma Wenyu Yu Wenyu Yu Fengling Li Fengling Li Wolfram Tempel Wolfram Tempel Nicolas Babault Nicolas Babault Fabio Pittella-Silva Fabio Pittella-Silva Jason Shao Jason Shao Junyi Wang Junyi Wang Minkui Luo Minkui Luo Masoud Vedadi Masoud Vedadi Peter J. Brown Peter J. Brown Cheryl H. Arrowsmith Cheryl H. Arrowsmith Jian Jin Jian Jin Structure-Based Design of a Covalent Inhibitor of the SET Domain-Containing Protein 8 (SETD8) Lysine Methyltransferase American Chemical Society 2016 cocrystal structure crystal structure Domain-Containing Protein 8 MS domain-containing protein 8 inhibitor binding site SETD 8 inhibitor SETD 8 protein lysine methyltransferases IC 50 value covalent inhibitor 2016-11-02 11:53:25 Journal contribution https://acs.figshare.com/articles/journal_contribution/Structure-Based_Design_of_a_Covalent_Inhibitor_of_the_SET_Domain-Containing_Protein_8_SETD8_Lysine_Methyltransferase/4185078 Selective inhibitors of protein lysine methyltransferases, including SET domain-containing protein 8 (SETD8), are highly desired, as only a fraction of these enzymes are associated with high-quality inhibitors. From our previously discovered SETD8 inhibitor, we developed a more potent analog and solved a cocrystal structure, which is the first crystal structure of SETD8 in complex with a small-molecule inhibitor. This cocrystal structure allowed the design of a covalent inhibitor of SETD8 (MS453), which specifically modifies a cysteine residue near the inhibitor binding site, has an IC<sub>50</sub> value of 804 nM, reacts with SETD8 with near-quantitative yield, and is selective for SETD8 against 28 other methyltransferases. We also solved the crystal structure of the covalent inhibitor in complex with SETD8. This work provides atomic-level perspective on the inhibition of SETD8 by small molecules and will help identify high-quality chemical probes of SETD8.