Download MendeleyMechanism of histone lysine methyl transfer revealed by the structure of SET7/9-AdoMet
Kwon, T., Chang, J.H., Kwak, E., Lee, C.W., Joachimiak, A., Kim, Y.C., Lee, J., Cho, Y.(2003) EMBO J 22: 292-303
- PubMed: 12514135
- DOI: https://doi.org/10.1093/emboj/cdg025
- Primary Citation of Related Structures:
1N6A, 1N6C - PubMed Abstract:
The methylation of lysine residues of histones plays a pivotal role in the regulation of chromatin structure and gene expression. Here, we report two crystal structures of SET7/9, a histone methyltransferase (HMTase) that transfers methyl groups to Lys4 of histone H3, in complex with S-adenosyl-L-methionine (AdoMet) determined at 1.7 and 2.3 A resolution. The structures reveal an active site consisting of: (i) a binding pocket between the SET domain and a c-SET helix where an AdoMet molecule in an unusual conformation binds; (ii) a narrow substrate-specific channel that only unmethylated lysine residues can access; and (iii) a catalytic tyrosine residue. The methyl group of AdoMet is directed to the narrow channel where a substrate lysine enters from the opposite side. We demonstrate that SET7/9 can transfer two but not three methyl groups to unmodified Lys4 of H3 without substrate dissociation. The unusual features of the SET domain-containing HMTase discriminate between the un- and methylated lysine substrate, and the methylation sites for the histone H3 tail.
Organizational Affiliation:
National Creative Research Initiative Center for Structural Biology and Department of Life Science, Pohang University of Science and Technology, Hyo-ja dong, San31, Pohang, KyungBook 790-784, South Korea.
