Structural and biochemical characterization of Rv0187, an O-methyltransferase from Mycobacterium tuberculosis.Lee, S., Kang, J., Kim, J.
(2019) Sci Rep 9: 8059-8059
- PubMed: 31147608
- DOI: https://doi.org/10.1038/s41598-019-44592-7
- Primary Citation of Related Structures:
- PubMed Abstract:
Catechol O-methyltransferase (COMT) is widely distributed in nature and installs a methyl group onto one of the vicinal hydroxyl groups of a catechol derivative. Enzymes belonging to this family require two cofactors for methyl transfer: S-adenosyl-l-methionine as a methyl donor and a divalent metal cation for regiospecific binding and activation of a substrate. We have determined two high-resolution crystal structures of Rv0187, one of three COMT paralogs from Mycobacterium tuberculosis, in the presence and absence of cofactors. The cofactor-bound structure clearly locates strontium ions and S-adenosyl-l-homocysteine in the active site, and together with the complementary structure of the ligand-free form, it suggests conformational dynamics induced by the binding of cofactors. Examination of in vitro activities revealed promiscuous substrate specificity and relaxed regioselectivity against various catechol-like compounds. Unexpectedly, mutation of the proposed catalytic lysine residue did not abolish activity but altered the overall landscape of regiospecific methylation.
Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju, 61005, Republic of Korea. firstname.lastname@example.org.