Discovery of a plant-like tridomain bifunctional syn-abieta-7,13-diene synthase in Streptomyces.

Bacteria have been long proposed to harbor ancestral forms of the bifunctional terpene synthases found in plants. Recent studies described the first identification of these fused bacterial diterpene cyclases/synthases (DCSs). Using genome mining, we found candidate proteins in bacteria that were bioinformatically identified to possess both classes of terpene synthase domains. Here, we report the discovery of a plant-like tridomain bifunctional DCS from Streptomyces albulus. A diterpene overproduction system in E. coli enabled the isolation and structural elucidation of syn-abieta-7,13-diene by NMR, GC-MS, and VCD.