Chemical wizardry? The generation of diversity in terpenoid biosynthesis*

Terpene synthases catalyze the conversion of linear prenyl-diphosphates to a multitude of hydrocarbon skeletons with often high regioand stereoselectivity. These remarkable enzymes all rely on a shared fold for activity, namely, the class I terpene cyclase fold. Recent work has illuminated the catalytic strategy used by these enzymes to catalyze the arguably most complex chemical reactions found in Nature. Terpene synthases catalyze the formation of a reactive carbocation and provide a template for the cyclization reactions while at the same time providing the necessary stability of the carbocationic reaction intermediates as well as strictly controlling water access.