Terpendole E, a kinesin Eg5 inhibitor, is a key biosynthetic intermediate of indole-diterpenes in the producing fungus Chaunopycnis alba.

Terpendole E is the first natural product inhibitor of kinesin Eg5. Because terpendole E production is unstable, we isolated and analyzed the terpendole E biosynthetic gene cluster, which consists of seven genes encoding three P450 monooxygenases (TerP, TerQ, and TerK), an FAD-dependent monooxygenase (TerM), a terpene cyclase (TerB), and two prenyltransferases (TerC and TerF). Gene knockout and feeding experiments revealed that terpendole E is a key intermediate in terpendole biosynthesis and is produced by the action of the key enzyme TerQ from paspaline, a common biosynthetic intermediate of indole-diterpenes. TerP converts terpendole E to a downstream intermediate specific to terpendole biosynthesis and converts paspaline to shunt metabolites. We successfully overproduced terpendole E by disrupting the terP gene. We propose that terpendole E is a key biosynthetic intermediate of terpendoles and related indole-diterpenes.