| The 2.5A structure of recombinant aristolochene synthase from Penicillium roqueforti reveals structural features common with other terpene cyclases. These features are critical to the cyclization of the substrate molecule farnesyl diphosphate into the product hydrocarbon aristolochene. In this mechanism, metal triggered carbocation formation initiates the reaction, which then proceeds through multiple, elaborate intermediate steps to yield one stereochemical isomer of aristolochene. The structure of aristolochene synthase in complex with the ligand farnesol provide a structural backdrop for this complex series of reactions. Despite minimal sequence identity, structural homology of this sesquiterpene cyclase with other terpene synthases suggests diversion from a common, primordial ancestor. |
