Elucidation of tropane alkaloid biosynthesis inErythroxylum cocausing a microbial pathway discovery platform

transcriptome datasets to discover a cytochrome P450 of the CYP81A family responsible for the second tropane ring closure in Erythroxylaceae, and demonstrate the function of the core coca TA pathway in vivo via reconstruction and de novo biosynthesis of methylecgonine in yeast. Collectively, our results provide strong evidence that TA biosynthesis in Erythroxylaceae and Solanaceae is polyphyletic and that independent recruitment of unique biosynthetic mechanisms and enzyme classes occurred at nearly every step in the evolution of this pathway.