Discovery and engineering of colchicine alkaloid biosynthesis

• Published in: Nature (London) Vol. 584; no. 7819; pp. 148 - 153
• Main Authors: Nett, Ryan S, Lau, Warren, Sattely, Elizabeth S
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 06.08.2020
• Subjects: Alkaloids; Amino acids; Bioactive compounds; Biosynthesis; Biosynthetic Pathways - genetics; Carbon; Cloning; Colchicaceae - enzymology; Colchicaceae - genetics; Colchicaceae - metabolism; Colchicine; Colchicine - biosynthesis; Colchicine - chemistry; Colchicine - metabolism; Cytochrome; Cytochrome P-450 Enzyme System - metabolism; Cytochrome P450; Cytochromes P450; Enzymes; FDA approval; Gene Expression Regulation, Plant; Genes; Genomes; Herbal medicine; Inflammatory diseases; Medicinal plants; Metabolic Engineering; Metabolism; Metabolites; Metabolomics; Nicotiana - genetics; Nicotiana - metabolism; Phenols; Phenylalanine; Phenylalanine - metabolism; Plants; Regulatory agencies; Transcriptome; Tyrosine; Tyrosine - metabolism
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-020-2546-8

Few complete pathways have been established for the biosynthesis of medicinal compounds from plants. Accordingly, many plant-derived therapeutics are isolated directly from medicinal plants or plant cell culture . A lead example is colchicine, a US Food and Drug Administration (FDA)-approved treatment for inflammatory disorders that is sourced from Colchicum and Gloriosa species . Here we use a combination of transcriptomics, metabolic logic and pathway reconstitution to elucidate a near-complete biosynthetic pathway to colchicine without prior knowledge of biosynthetic genes, a sequenced genome or genetic tools in the native host. We uncovered eight genes from Gloriosa superba for the biosynthesis of N-formyldemecolcine, a colchicine precursor that contains the characteristic tropolone ring and pharmacophore of colchicine . Notably, we identified a non-canonical cytochrome P450 that catalyses the remarkable ring expansion reaction that is required to produce the distinct carbon scaffold of colchicine. We further used the newly identified genes to engineer a biosynthetic pathway (comprising 16 enzymes in total) to N-formyldemecolcine in Nicotiana benthamiana starting from the amino acids phenylalanine and tyrosine. This study establishes a metabolic route to tropolone-containing colchicine alkaloids and provides insights into the unique chemistry that plants use to generate complex, bioactive metabolites from simple amino acids.