Probing the Role of the DXDD Motif in Class II Diterpene Cyclases

Abstract

On common ground. An epoxy analogue of geranylgeranyl diphosphate was used together with site-directed mutagenesis to provide evidence that the DXDD motif in class II diterpene cyclases is involved in CC double-bond protonation (see scheme). This function is similar to the role of the DXDD motif found in the otherwise unrelated triterpene cyclases, which also catalyze CC protonation initiated cyclization.