Engineering Plant-Derived P450 Enables the Efficient Production of Berberine through a Concise and Modular Enzymatic Cascade in <i>E. coli</i>

Sustainable and scalable production of plant natural products remains a major challenge at the interface of synthetic biology, metabolic engineering, and drug discovery, often constrained by plant-membrane-bound cytochrome P450s. To overcome the bottleneck in P450-catalyzed methylenedioxy-bridge (MDB) formation, we designed a concise, modular Escherichia coli pathway to the alkaloid berberine that bypasses multiple native steps and enables high-level accumulation of the P450-dependent intermediate. We then implemented integrated engineering of CjCYP719A1, including expression optimization, structure-guided design, consensus mutagenesis, and machine learning, to obtain a variant with 8.9-fold higher activity and improved thermostability. This enabled a berberine titer of 353 mg/L in scaled-up preparations, the highest reported to date, demonstrating industrial potential. Furthermore, mechanistic studies reveal their improved catalytic activity and thermostability. Together, this work provides a practical framework for functional expression and systematic optimization of plant-derived P450s to enable efficient production of plant natural products in E. coli.