IN-VIVO AND IN-VITRO BIOCONVERSION OF EPSILON-RHODOMYCINONE GLYCOSIDETO DOXORUBICIN - FUNCTIONS OF DAUP, DAUK, AND DOXA

We recently determined the function of the gene product of Steptomyces sp. strain C5 doxA, a cytochrome P-450-like protein, to be daunorubic in C-14 hydroxylase (M. L. Dickens and W. R. Strohl, J. Bacteriol, 178 : 3389-3395, 1996), In the present study, we show that DoxA also catal yzes the hydroxylation of 13-deoxycarminomycin and 13-deoxydaunorubici n 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 epsilo n-rhodomycinone-glycoside (rhodomycin D) to form 10-carboxy-13-deoxyca rminomycin. Additionally, Streptomyces sp, strain C5 DauK was found to methylate the anthracyclines rhodomycin D, 10-carboxy-13-deoxycarmino mycin, and 13-deoxy-carminomycin, at the 4-hydroxyl position, indicati ng a broader substrate specificity than was previously known, The prod ucts of Streptomyces sp. strain C5 doxA, dauK, and dauP were sufficien t and necessary to confer on Streptomyces lividans TK24 the ability to convert rhodomycin D, the first glycoside in daunorubicin and doxorub icin biosynthesis, to doxorubicin.