Conserved Organization of Genes for Biosynthesis of Chlortetracycline in Streptomyces Strains

By genomic Southern blot analysis, the DNA sequences homologous to the gene cluster responsible for biosynthesis of 6-demethylchlortetracycline in Streptomyces aureofaciens NRRL3203 were shown to be highly conserved in independent chlortetracycline- or tetracycline producing Streptomyces strains. By contrast, oxytetracycline-producing Streptomyces strains had no hybridization with the cluster DNA.