| Abstract: | The erythromycin resistance gene (ermE) and part of erythromycin biosynthesis genes located in the same cluster with the ermE gene were cloned from S. erythraeus 3 subjected to improvement with respect to erythromycin production. For isolating the erythromycin biosynthesis genes, the plasmid vector pUC18 and the phage vector lambda EMBL3 were used. The ermE gene DNA was used as a labeled probe for analysis of the recombinant plasmids and phages. The recombinant phages lambda ermE1 and ermE4 containing fragments of the chromosomal DNA collinear to the genome DNA of S. erythraeus 3 were analyzed. The size of the cloned fragment of the chromosomal DNA of S. erythraeus 3 was about 20 kb. Subcloning with the vector pUS18 resulted in isolation of plasmids pSU235-pSU244 containing BamHI fragments of chromosomal DNA from S. erythraeus 3. The restriction map of the chromosomal region of S. erythraeus 3 containing the ermE gene was constructed. The cloned genes of erythromycin biosynthesis are useful in the study of their structure and functions, construction of integrative vectors, improvement of cultures producing macrolide antibiotics and isolation of genes responsible for biosynthesis of other polyketide antibiotics. |
