Structures of histone methyltransferase SET7/9 in complexes with adenosylmethionine derivatives
Niwa, H., Handa, N., Tomabechi, Y., Honda, K., Toyama, M., Ohsawa, N., Shirouzu, M., Kagechika, H., Hirano, T., Umehara, T., Yokoyama, S.(2013) Acta Crystallogr D Biol Crystallogr 69: 595-602
- PubMed: 23519668 
- DOI: https://doi.org/10.1107/S0907444912052092
- Primary Citation of Related Structures:  
3VUZ, 3VV0 - PubMed Abstract: 
SET7/9 is a protein lysine methyltransferase that methylates histone H3 and nonhistone proteins such as p53, TAF10 and oestrogen receptor α. In previous work, novel inhibitors of SET7/9 that are amine analogues of the coenzyme S-(5'-adenosyl)-L-methionine (AdoMet) have been developed. Here, crystal structures of SET7/9 are reported in complexes with two AdoMet analogues, designated DAAM-3 and AAM-1, in which an n-hexylaminoethyl group or an n-hexyl group is attached to the N atom that replaces the S atom of AdoMet, respectively. In both structures, the inhibitors bind to the coenzyme-binding site and their additional alkyl chain binds in the lysine-access channel. The N atom in the azaalkyl chain of DAAM-3 is located at almost the same position as the N-methyl C atom of the methylated lysine side chain in the substrate-peptide complex structures and stabilizes complex formation by hydrogen bonding to the substrate-binding site residues of SET7/9. On the other hand, the alkyl chain of AAM-1, which is a weaker inhibitor than DAAM-3, binds in the lysine-access channel only through hydrophobic and van der Waals interactions. Unexpectedly, the substrate-binding site of SET7/9 complexed with AAM-1 specifically interacts with the artificial N-terminal sequence of an adjacent symmetry-related molecule, presumably stabilizing the alkyl chain of AAM-1.
Organizational Affiliation: 
RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama, Japan.