Identification and biochemical characterization of a 5-dimethylallyl tryptophan synthase in Streptomyces coelicolor A3(2)

The genome sequencing of Streptomyces coelicolor A3(2) has lead to the identification of numerous cryptic gene clusters involved in the biosynthesis of secondary metabolites; throwing open the challenge of identifying the enzymatic functions that the gene clusters are associated with. In this work, we report the biochemical characterization of one such cryptic gene, SCO7467 from S. coelicolor A3(2), which is annotated as a prenyltransferase. Based on LC–MS and 2D-NMR studies, we show that SCO7467 acts as a 5-dimethylallyl tryptophan synthase (5-DMATS), and catalyzes the transfer of a dimethylallyl group to the C-5 position of the indole ring of l-tryptophan. The studies indicate that SCO7467 could be involved in the synthesis of C-5 prenylated indole alkaloids, which may exhibit unique pharmacological and biological properties.