IUBMB Enzyme Nomenclature


Accepted name: erythromycin 3"-O-methyltransferase

Reaction: (1) S-adenosyl-L-methionine + erythromycin C = S-adenosyl-L-homocysteine + erythromycin A
(2) S-adenosyl-L-methionine + erythromycin D = S-adenosyl-L-homocysteine + erythromycin B

For diagram of reaction click here.

Other name(s): EryG

Systematic name: S-adenosyl-L-methionine:erythromycin C 3"-O-methyltransferase

Comments: The enzyme methylates the 3 position of the mycarosyl moiety of erythromycin C, forming the most active form of the antibiotic, erythromycin A. It can also methylate the precursor erythromycin D, forming erythromycin B, which is then converted to erythromycin A by EC, erythromycin 12-hydroxylase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Paulus, T.J., Tuan, J.S., Luebke, V.E., Maine, G.T., DeWitt, J.P. and Katz, L. Mutation and cloning of eryG, the structural gene for erythromycin O-methyltransferase from Saccharopolyspora erythraea, and expression of eryG in Escherichia coli. J. Bacteriol. 172 (1990) 2541-2546. [PMID: 2185226]

2. Summers, R.G., Donadio, S., Staver, M.J., Wendt-Pienkowski, E., Hutchinson, C.R. and Katz, L. Sequencing and mutagenesis of genes from the erythromycin biosynthetic gene cluster of Saccharopolyspora erythraea that are involved in L-mycarose and D-desosamine production. Microbiology 143 (1997) 3251-3262. [PMID: 9353926]

[EC created 2012]

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