Cloning and sequencing of a gene encoding carminomycin 4-O-methyltransferase from Streptomyces peucetius and its expression in Escherichia coli

Carminomycin 4-O-methyltransferase (COMT) catalyzes the final step in the biosynthesis of daunorubicin, an anthracycline antibiotic which displays antitumor activity and cardiotoxicity. The Streptomyces peucetius gene coding for COMT was isolated and characterized. The gene, designated dnrK, was also expressed in Escherichia coli. The expressed protein is a 166-kDa homotetramer composed of 41-kDa subunits.