Mechanistic Characterisation and Engineering of Sesterviolene Synthase from Streptomyces violens

Abstract

The sesterviolene synthase from Streptomyces violens was identified and represents the second known sesterterpene synthase from bacteria. Isotopic labelling experiments in conjunction with DFT calculations were performed that provided detailed insight into its complex cyclisation mechanism. Enzyme engineering through site‐directed mutagenesis gave access to a high‐yielding enzyme variant that provided six additional minor products and the main product in sufficient quantities to study its chemistry.

Spiroluchuene A Synthase: A Cyclase from Aspergillus luchuensis Forming a Spirotetracyclic Diterpene

“…and S16) to allow for an identification of residues potentially involved in catalysis [40,41] . Noticeable differences between AlTS and SpS were observed for the AlTS active‐site residues L86, I102, I106, G213, V214 and S251 located in positions that were previously shown to be hotspots for the change of the functions of terpene synthases [24,42–46] . The corresponding positions of SpS are occupied by F77, V93, F97, A208, A209 and V246.…”

Hot off the Press

“…The bacterial sesterterpene synthase (SvSS) from Streptomyces violens , which produces sesterviolenes such as sesterviolene A 23 , has been identified. 21 A combination of feeding studies and DFT calculations have elucidated the complex cyclisation mechanism of SvSS, which produces sesterviolene A 23 from geranylfarnesyl diphosphate.…”

Mechanistic Characterisation of the Bacterial Sesterviridene Synthase from Kitasatospora viridis

“…Also in bacteria sesterterpene biosynthesis is catalysed by two discrete enzymes, a GFPPS and a TS. Besides the UbiA related sesterterpene synthase for somaliensenes from Streptomyces somaliensis [14] and the type II terpene synthase involved in atylopene biosynthesis, [15] the only two characterised type I sesterterpene synthases are SmTS1 from Streptomyces mobaraensis with the main product sestermobaraene A ( 6 ), [16] and the sesterviolene ( 7 ) synthase SvSS from Streptomyces violens [17] . After our recent discovery of the sesquiterpene synthase for kitaviridene from Kitasatospora viridis , [18] we now report on the identification of a sesterterpene synthase from the same organism and its mechanistic characterisation through isotopic labelling experiments and DFT calculations.…”