IUBMB Enzyme Nomenclature


Accepted name: 5a,11a-dehydrotetracycline 5-monooxygenase

Reaction: 5a,11a-dehydrotetracycline + NADPH + H+ + O2 = 5a,11a-dehydrooxytetracycline + NADP+ + H2O

For diagram of reaction click here.

Glossary: 5a,11a-dehydrotetracycline = 12-dehydrotetracycline = (4S,4aS,6S,12aS)-4-dimethylamino-3,6,10,12a-tetrahydroxy-6-methyl-1,11,12-trioxo-1,4,4a,5,6,11,12,12a-octahydrotetracene-2-carboxamide

Other name(s): oxyS (gene name); 12-dehydrotetracycline 5-monooxygenase

Systematic name: 5a,11a-dehydrotetracycline,NADPH:oxygen oxidoreductase (5-hydroxylating)

Comments: The enzyme, characterized from the bacterium Streptomyces rimosus, is bifunctional, catalysing two successive monooxygenation reactions. It starts by catalysing the stereospecific hydroxylation of anhydrotetracycline at C-6 (EC If the released product is captured by EC, 5a,11a-dehydrotetracycline dehydrogenase (OxyR), it is reduced to tetracycline. However, if the released product is recaptured by OxyS, it performs an additional hydroxylation at C-5, producing 5a,11a-dehydrooxytetracycline, which, following the action of OxyR, becomes oxytetracycline.

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


1. Binnie, C., Warren, M. and Butler, M.J. Cloning and heterologous expression in Streptomyces lividans of Streptomyces rimosus genes involved in oxytetracycline biosynthesis. J. Bacteriol. 171 (1989) 887-895. [PMID: 2914874]

2. Miller, P.A., Saturnelli, A., Martin, J.H., Itscher, L.A. and Bohonos, N. A new family of tetracycline precursors. N-demethylanhydrotetracyclines. Biochem. Biophys. Res. Commun. 16 (1964) 285-291. [PMID: 4959040]

3. Vancurova, I., Volc, J., Flieger, M., Neuzil, J., Novotna, J., Vlach, J. and Behal, V. Isolation of pure anhydrotetracycline oxygenase from Streptomyces aureofaciens. Biochem. J. 253 (1988) 263-267. [PMID: 3138982]

4. Wang, P., Bashiri, G., Gao, X., Sawaya, M.R. and Tang, Y. Uncovering the enzymes that catalyze the final steps in oxytetracycline biosynthesis. J. Am. Chem. Soc. 135 (2013) 7138-7141. [PMID: 23621493]

[EC created 2016]

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