CLONING AND HETEROLOGOUS EXPRESSION OF THE ENTIRE GENE CLUSTERS FOR PD-116740 FROM STREPTOMYCES STRAIN WP-4669 AND TETRANGULOL AND TETRANGOMYCIN FROM STREPTOMYCES-RIMOSUS NRRL-3016

The genes for the complete pathways for two polycyclic aromatic polyke tides of the angucyclinone class have been cloned and heterologously e xpressed, Genomic DNAs of Streptomyces rimosus NRRL 3016 and Streptomy ces strain WP 4669 were partially digested with MboI, and libraries (c a, 40-kb fragments) in Escherichia coli XL1-Blue MR were prepared with the cosmid vector pOJ446. Hybridization with the actI probe from the actinorhodin polyketide synthase genes identified two clusters of poly ketide genes from each organism, After transfer of the four clusters t o Streptomyces lividans TK24, expression of one cluster from each orga nism was established through the identification of pathway-specific pr oducts by high-performance liquid chromatography with photodiode array detection, Peaks were identified from the S. rimosus cluster (pks(RIM -1)) for tetrangulol, tetrangomycin, and fridamycin E. Peaks were iden tified from the WP 4669 cluster (pks(WP-2)) for tetrangulol, 19-hydrox ytetrangulol, 8-O-methyltetrangulol, 19-hydroxy-8-O-methyltetrangulol, and PD 116740, Structures were confirmed by H-1 nuclear magnetic reso nance spectroscopy and high-resolution mass spectrometry.