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



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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[DOUBLE BOND]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[DOUBLE BOND]C protonation initiated cyclization.