Biosynthese der Anthracycline: eine Neuinterpretation der Ergebnisse zur Daunomycin‐Biosynthese

Wagner, Christina; Eckardt, K.; Ihn, W.; Schumann, G.; Stengel, Cornelia; Fleck, W. F.; Tresselt, D.

doi:10.1002/jobm.3620310311

Cited by 15 publications

(2 citation statements)

References 48 publications

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“…The reactions and genes governing the biosynthesis of daunorubicin and doxorubicin from ε-rhodomycinone have been widely postulated (23,45,48,53) but have not previously been proven. The current hypothesis (23,42), based initially on the discovery of carminomycin 4-O-methyltransferase (8) and the frequency of mutations leading to the accumulation of ε-rhodomycinone (3), is that ε-rhodomycinone is glycosylated in the presence of TDP-daunosamine and a glycosyltransferase (now thought to be DnrS [38]) to form the glycoside (10-methoxycarbonyl-13-deoxocarminomycin [compound D788-6]; here renamed rhodomycin D), which has been isolated as an accumulated product from mutants of a baumycin-producing strain, Streptomyces sp.…”

Section: Resultsmentioning

confidence: 99%

In vivo and in vitro bioconversion of epsilon-rhodomycinone glycoside to doxorubicin: functions of DauP, DauK, and DoxA

1997

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We recently determined the function of the gene product of Streptomyces sp. strain C5 doxA, a cytochrome P-450-like protein, to be daunorubicin C-14 hydroxylase (M. L. Dickens and W. R. Strohl, J. Bacteriol. 178: [3389][3390][3391][3392][3393][3394][3395] 1996). In the present study, we show that DoxA also catalyzes the hydroxylation of 13-deoxycarminomycin and 13-deoxydaunorubicin to 13-dihydrocarminomycin and 13-dihydrodaunorubicin, respectively, as well as oxidizing the 13-dihydro-anthracyclines to their respective 13-keto forms. The Streptomyces sp. strain C5 dauP gene product also was shown unequivocally to remove the carbomethoxy group of the -rhodomycinone-glycoside (rhodomycin D) to form 10-carboxy-13-deoxycarminomycin. Additionally, Streptomyces sp. strain C5 DauK was found to methylate the anthracyclines rhodomycin D, 10-carboxy-13-deoxycarminomycin, and 13-deoxy-carminomycin, at the 4-hydroxyl position, indicating a broader substrate specificity than was previously known. The products of Streptomyces sp. strain C5 doxA, dauK, and dauP were sufficient and necessary to confer on Streptomyces lividans TK24 the ability to convert rhodomycin D, the first glycoside in daunorubicin and doxorubicin biosynthesis, to doxorubicin. Daunorubicin (daunomycin [11,17]) and doxorubicin (14-hydroxydaunorubicin; adriamycin [2]) ( Fig. 1) are clinically important anthracycline chemotherapeutic agents (2, 11, 17), which are synthesized by a type II polyketide synthase (23,(42)(43)(44). The aglycone is formed by condensing nine extender units derived from malonyl coenzyme A onto a propionyl moiety to make a C 21 polyketide intermediate (21,23,(42)(43)(44)(45)50), which is reduced at C-9 from the carboxy terminus (43, 44), cyclized, and aromatized to form aklanonic acid (18,19,23,40,(42)(43)(44). Aklanonic acid is converted in four steps to ε-rhodomycinone (3,7,15,16,30,40,42,44), an intermediate that is accumulated in large quantities by most daunorubicin-producing strains (27,42,44,46). It is postulated that ε-rhodomycinone is glycosylated by condensation with TDP-daunosamine (3,8,23,38,42,44) to form the first glycoside intermediate, here named rhodomycin D, which is then converted by a series of reactions to daunorubicin and doxorubicin. Previously, however, the order of the reactions and the enzymes catalyzing some of the steps in the conversion of rhodomycin D to doxorubicin were not known. We recently showed that the doxA gene of Streptomyces sp. strain C5 encoded a cytochrome P-450 enzyme that was capable of conferring on Streptomyces lividans TK24 the ability to convert daunorubicin to doxorubicin (14). In the present work, we describe the enzymatic activities from Streptomyces sp. strain C5 that are responsible for the conversion of rhodomycin D to doxorubicin both in vivo and in vitro (Fig. 1). MATERIALS AND METHODSBacterial strains, plasmids, media, and genetic manipulations. Streptomyces sp. strain C5, originally obtained from the Frederick Cancer Research Center (33) and previously described in detail (3), was...

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Section: Resultsmentioning

confidence: 99%

In vivo and in vitro bioconversion of epsilon-rhodomycinone glycoside to doxorubicin: functions of DauP, DauK, and DoxA

1997

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“…It was argued therefore that decanoate (78) is a direct precursor and that its incorporation implicates poxidation intermediates as an additional source of the monomer. p-Oxidation would be expected to generate the wrong 3 s enantiomer (79) for the polymer, therefore an epimerase is proposed to convert the 3 s centre into 3R as outlined in Scheme 15. Future studies will hopefully clarify this intriguing problem.…”

Section: From Bacteriamentioning

confidence: 99%