IUBMB Enzyme Nomenclature


Accepted name: 2,7-dihydroxy-5-methyl-1-naphthoate 7-O-methyltransferase

Reaction: S-adenosyl-L-methionine + 2,7-dihydroxy-5-methyl-1-naphthoate = S-adenosyl-L-homocysteine + 2-hydroxy-7-methoxy-5-methyl-1-naphthoate

For diagram of reaction click here.

Other name(s): NcsB1; neocarzinostatin O-methyltransferase

Systematic name: S-adenosyl-L-methionine:2,7-dihydroxy-5-methyl-1-naphthoate 7-O-methyltransferase

Comments: The enzyme from the bacterium Streptomyces carzinostaticus is involved in the biosynthesis of 2-hydroxy-7-methoxy-5-methyl-1-naphthoate. This compound is part of the enediyne chromophore of the antitumor antibiotic neocarzinostatin. In vivo the enzyme catalyses the regiospecific methylation at the 7-hydroxy group of its native substrate 2,7-dihydroxy-5-methyl-1-naphthoate. In vitro it also recognizes other dihydroxynaphthoic acids and catalyses their regiospecific O-methylation.

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


1. Luo, Y., Lin, S., Zhang, J., Cooke, H.A., Bruner, S.D. and Shen, B. Regiospecific O-methylation of naphthoic acids catalyzed by NcsB1, an O-methyltransferase involved in the biosynthesis of the enediyne antitumor antibiotic neocarzinostatin. J. Biol. Chem. 283 (2008) 14694-14702. [PMID: 18387946]

2. Cooke, H.A., Guenther, E.L., Luo, Y., Shen, B. and Bruner, S.D. Molecular basis of substrate promiscuity for the SAM-dependent O-methyltransferase NcsB1, involved in the biosynthesis of the enediyne antitumor antibiotic neocarzinostatin. Biochemistry 48 (2009) 9590-9598. [PMID: 19702337]

[EC created 2014]

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