Journal Article

Dioxygenases catalyze the O-demethylation steps of morphine biosynthesis in opium poppy

Hagel, Jillian M, Facchini, Peter J

2010

Overview

A plant mutant that fails to accumulate morphine provides a genetic clue to identifying the last two enzymes in this alkaloid biosynthetic pathway. Surprisingly, the proteins are non-heme dioxygenases, thus expanding the range of this versatile class of catalysts. Two previously undetected enzymes involved in morphine biosynthesis and unique among plants to opium poppy have been identified as non-heme dioxygenases, in contrast to the functionally analogous cytochrome P450s found in mammals. We used functional genomics to isolate thebaine 6-O-demethylase (T6ODM) and codeine O-demethylase (CODM), the only known 2-oxoglutarate/Fe( II )-dependent dioxygenases that catalyze O-demethylation. Virus-induced gene silencing of T6ODM and CODM in opium poppy efficiently blocked metabolism at thebaine and codeine, respectively.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: 631/1647/334/2244 / 631/208/176/2016 / 631/443/319 / 631/92/60 / Biocatalysis / Biochemical Engineering / Biochemistry / Bioorganic Chemistry / Biosynthesis / Botany / brief-communication / Cell Biology / Chemistry / Chemistry and Materials Science / Chemistry/Food Science / Cytochrome / Dioxygenases - metabolism / Genomics / Mammals / Metabolism / Methylation / Morphine - biosynthesis / Morphine - chemistry / Narcotics / Papaver - chemistry / Papaver - enzymology / Papaver - metabolism