The enzyme, found in mycobacteria, is a member of a family of heterocyclic toxin methyltransferases. It is involved in defense against several antimicrobial natural compounds and drugs. 4-Hydroxyquinolin-2(1H)-one, 2-heptylquinolin-4(1H)-one, 2-heptyl-3-hydroxyquinolin-4(1H)-one (the "Pseudomonas quinolone signal", PQS) and the flavonol quercetin are also O-methylated, albeit with lower activity . The enzyme also N-methylates the bactericidal compound 3-methyl-1-oxo-2-[3-oxo-3-(pyrrolidin-1-yl)propyl]-1,5-dihydrobenzo[4,5]imidazo[1,2-a]pyridine-4-carbonitrile .
Warrier T, Kapilashrami K, Argyrou A, Ioerger TR, Little D, Murphy KC, Nandakumar M, Park S, Gold B, Mi J, Zhang T, Meiler E, Rees M, Somersan-Karakaya S, Porras-De Francisco E, Martinez-Hoyos M, Burns-Huang K, Roberts J, Ling Y, Rhee KY, Mendoza-Losana A, Luo M, Nathan CF.
N-methylation of a bactericidal compound as a resistance mechanism in Mycobacterium tuberculosis.