Scaffold-Adaptive P450 Enzymes Balance Substrate Promiscuity with Catalytic Specificity in Brassicicene Biosynthesis

We investigated the functional plasticity of two P450 enzymes, AbnK and AbnG, in the brassicicene biosynthetic pathway. Through in vivo heterologous expression, feeding assays, and in vitro reactions, we show that these enzymes regio- and stereoselectively transform both 5-8-5 and 5-9-5 terpenoid scaffolds in different ways, supported by computational simulations. AbnK also bridges a missing step in brassicicene A biosynthesis. Our findings demonstrate how controlled promiscuity underpins structural diversity, informing strategies to expand chemoenzymatic synthesis.