Meroterpenoids are hybrid natural products of both terpenoid and polyketide origin. We identified a biosynthetic gene cluster that is responsible for the production of the meroterpenoid pyripyropene in the fungus Aspergillus fumigatus through reconstituted biosynthesis of up to five steps in a heterologous fungal expression system. The cluster revealed a previously unknown terpene cyclase with an unusual sequence and protein primary structure. The wide occurrence of this sequence in other meroterpenoid and indole-diterpene biosynthetic gene clusters indicates the involvement of these enzymes in the biosynthesis of various terpenoid-bearing metabolites produced by fungi and bacteria. In addition, a novel polyketide synthase that incorporated nicotinyl-CoA as the starter unit and a prenyltransferase, similar to that in ubiquinone biosynthesis, was found to be involved in the pyripyropene biosynthesis. The successful production of a pyripyropene analogue illustrates the catalytic versatility of these enzymes for the production of novel analogues with useful biological activities.
Itoh, T., Tokunaga, K., Matsuda, Y., Fujii, I., Abe, I., Ebizuka, Y., & Kushiro, T. (2010). Reconstitution of a fungal meroterpenoid biosynthesis reveals the involvement of a novel family of terpene cyclases. Nature Chemistry, 2(10), 858–864. https://doi.org/10.1038/nchem.764