Disruption and Compensation of dnmV gene from Daunorubicin-producing strain Streptomyces coeruleorubidus SIPI-1482
柔红霉素产生菌SIPI-1482中dnmV基因功能的阻断及恢复

TDP-4-ketohexulose reductase, encoded by dnmV, is important in daunorubicin biosynthesis. To obtain a daunorubicin block mutant, double cross-over plasmid pYG817 was constructed by inserting apramycin resistant gene and amplified dnmV together with upstream dnmU into vector pUC18. dnmV was successfully disrupted after transformation of daunorubicin-producing strain SIPI-1482 by pYG817. Daunorubicin was absent from metabolites of the resulting transformant, and its biosynthesis can be reconstituted by introducing dnmV expression plasmid into the disruptant, although the yield is lower than wild-type SIPI-1482, according to HPLC analysis. This mutant can be a good candidate for production of anthracycline such as epi-daunorubicin by introducing exogenous gene into the host.