Conserved early steps of stemmadenine biosynthesis.

ABSTRACT: Stemmadenine acetate is a pivotal intermediate in the production of pharmacologically active monoterpene indole alkaloids. Here, we identify orthologs of the stemmadenine acetate pathway genes (SGD, GS, GO, Redox1, Redox2, and SAT). We characterize these enzymes in vitro, and in addition, we reconstitute stemmadenine acetate biosynthesis in Nicotiana benthamiana, comparing the formation of intermediates and shunt products that are produced when previously characterized orthologs from the plant Catharanthus roseus are used. Ortholog pairs are catalytically indistinguishable, except in the case of geissoschizine synthase. Surprisingly, the geissoschizine synthase ortholog catalyzes the formation of an alternative stereoisomer, 19Z-geissoschizine, seeding a low-flux Z-series in heterologous r

SUBMITTER: Kamileen MO 

PROVIDER: S-EPMC12860956 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature