EC	5.5.1.23
Accepted name:	aklanonic acid methyl ester cyclase
Reaction:	aklaviketone = methyl aklanonate
Glossary:	aklaviketone = methyl (1R,2R)-2-ethyl-2,5,7-trihydroxy-4,6,11-trioxo-1,2,3,4,6,11-hexahydrotetracene-1-carboxylate methyl aklanonate = methyl [4,5-dihydroxy-9,10-dioxo-3-(3-oxopentanoyl)-9,10-dihydroanthracen-2-yl]acetate
Other name(s):	dauD (gene name); aknH (gene name); dnrD (gene name); methyl aklanonate cyclase; methyl aklanonate-aklaviketone isomerase (cyclizing); aklaviketone lyase (decyclizing)
Systematic name:	aklaviketone lyase (ring-opening)
Comments:	The enzyme is involved in the biosynthesis of aklaviketone, an intermediate in the biosynthetic pathways leading to formation of several anthracycline antibiotics, including aclacinomycin, daunorubicin and doxorubicin.
References:	1.  Dickens, M.L., Ye, J. and Strohl, W.R. Analysis of clustered genes encoding both early and late steps in daunomycin biosynthesis by Streptomyces sp. strain C5. J. Bacteriol. 177 (1995) 536–543. [PMID: 7836284] 2.  Kendrew, S.G., Katayama, K., Deutsch, E., Madduri, K. and Hutchinson, C.R. DnrD cyclase involved in the biosynthesis of doxorubicin: purification and characterization of the recombinant enzyme. Biochemistry 38 (1999) 4794–4799. [PMID: 10200167] 3.  Kallio, P., Sultana, A., Niemi, J., Mantsala, P. and Schneider, G. Crystal structure of the polyketide cyclase AknH with bound substrate and product analogue: implications for catalytic mechanism and product stereoselectivity. J. Mol. Biol. 357 (2006) 210–220. [PMID: 16414075]
[EC 5.5.1.23 created 2013, modified 2014]