Discovery of a P450-catalyzed step in vindoline biosynthesis: a link between the aspidosperma and eburnamine alkaloids

Abstract

Here we report the discovery of a cytochrome P450 that is required for the biosynthesis of vindoline, a plant-derived natural product used for semi-synthesis of several anti-cancer drugs. This enzyme catalyzes the formation of an epoxide that can undergo rearrangement to yield the vincamine-eburnamine backbone, thereby providing evidence for the long-standing hypothesis that the aspidosperma- and eburnamine-type alkaloids are biosynthetically related.

Gene Discovery in Gelsemium Highlights Conserved Gene Clusters in Monoterpene Indole Alkaloid Biosynthesis

“…Quality assessments of the G. sempervirens v3 genome assembly revealed robust representation of the genome and gene space with 88 % of the paired‐end genomic reads aligning to the assembly in the correct orientation and 93.1 % of the BUSCO orthologues present (86.1 % complete, 7.0 % fragmented) . Although a genome assembly is available for C. roseus , it has limited contiguity (N 50 scaffold length 27.3 kb; total size 506 Mb, 41 176 scaffolds), and thus, we generated an improved genome assembly for C. roseus to enable genomic comparisons between the two species. Using a set of paired‐end and mate pair libraries, we generated a 541 Mb assembly (v2) of C. roseus composed of 2090 scaffolds with an N 50 scaffold size of 2 579 454 bp, a significant improvement in assembly metrics; re‐annotation of v2 of the genome yielded 34 363 genes.…”

Isolation of Cells Specialized in Anticancer Alkaloid Metabolism by Fluorescence-Activated Cell Sorting

“…The TIA pathway presents multicellular compartmentation in C. roseus leaves, with early and middle steps being expressed in internal phloem-associated parenchyma and the epidermis, whereas late steps are expressed in laticifers and idioblasts, characterized by a conspicuous fluorescence (St-Pierre et al, 1999;Courdavault et al, 2014). A diversity of C. roseus transcriptomic projects (MPGR, Phytometasyn, Cathacyc) has enabled a recent burst of research in the TIA pathway, leading to the full characterization of its iridoid/terpenoid precursor part, of late biosynthetic steps, and of the first TIA transporter (Yu and DeLuca, 2013;Miettinen et al, 2014;Stavrinides et al, 2015;Kellner et al, 2015). However, the last bottleneck part of the pathway leading to the anticancer alkaloids remains elusive, as well as most TIA transmembrane transporters and transcriptional regulators affecting VLB/vincristine levels.…”

Unleashing the Synthetic Power of Plant Oxygenases: From Mechanism to Application

“…In the latter reaction, the second turnover generates a dihydroxylated carbon center that dehydrates to an aldehyde prior to a third oxidation. In a similar manner, P450-dependent demethylation likely proceeds through hydroxylation, followed by decomposition to formaldehyde and the demethylated product (Kellner et al, 2015a). Another spontaneous rearrangement following hydroxylase activity by a P450 is thought to occur in (+)-menthofuran production by Mentha spicata (mint) CYP71A32 (Fig.…”