Functional characterization and transcriptional analysis of a gene cluster governing early and late steps in daunorubicin biosynthesis in Streptomyces peucetius

Abstract

Sequence analysis of the Streptomyces peucetius daunorubicin biosynthetic gene cluster revealed a partial (dnrQ) and two complete (dnrD and dnrP) open reading frames flanking dnrK. Bioconversion experiments showed that DnrD converts aklanonic acid methylester to aklaviketone and that DnrC is a methyltransferase that converts aklanonic acid to aklanonic acid methylester. The deduced dnrP gene product, homologous to known esterases, may catalyze the conversion of 10-carbomethoxy-13-deoxycarminomycin to its 10-carboxy derivative. The dnrKPQS genes may be transcribed as a polycistronic mRNA.