2016 Volume 64 Issue 7 Pages 947-951
Non-reducing iterative type I polyketide synthase genes, pnk1 and pnk2, were cloned from the fungus Phoma sp. BAUA2861, which produces the topoisomerase I inhibitors, topopyrones A to D. Heterologous expression of these polyketide synthase genes under the α-amylase promoter in Aspergillus oryzae was carried out to identify their functions. The pnk2 transformant produced topopyrones C, D, and haematommone. Therefore, the pnk2 gene was found to encode for the topopyrone nonaketide synthase.