This is the N-terminal domain found in MycE from the mycinamicin biosynthetic pathway. MycE is a tetramer of a two-domain polypeptide, comprising a C-terminal catalytic MT domain and an N-terminal auxiliary domain, which is important for quaternary assembly and for substrate binding [1].

1: A new structural form in the SAM/metal-dependent omethyltransferase family: MycE from the mycinamicin biosynthetic pathway. Akey DL, Li S, Konwerski JR, Confer LA, Bernard SM, Anzai Y, Kato F, Sherman DH, Smith JL; J Mol Biol. 2011;413:438-450. PMID:21884704