FUNCTIONAL-CHARACTERIZATION AND TRANSCRIPTIONAL ANALYSIS OF A GENE-CLUSTER GOVERNING EARLY AND LATE STEPS IN DAUNORUBICIN BIOSYNTHESIS IN STREPTOMYCES-PEUCETIUS

Sequence analysis of the Streptomyces peucetius daunorubicin biosynthe tic gene cluster revealed a partial (dnrQ) and two complete (dnrD and dnrP) open reading frames flanking dnrK. Bioconversion experiments sho wed that DnrD converts aklanonic acid methylester to aklaviketone and that DnrC is a methyltransferase that converts aklanonic acid to aklan onic acid methylester. The deduced dnrP gene product, homologous to kn own esterases, may catalyze the conversion of 10-carbomethoxy-13-deoxy carminomycin to its 10-carboxy derivative. The dnrKPQS genes may be tr anscribed as a polycistronic mRNA.