Morphinan biosynthesis in opium poppy requires a P450-oxidoreductase fusion protein

Substrate channeling in morphine biosynthesis Poppies are still the most economically viable source of the excellent painkiller morphine. Winzer et al. have now identified a key enzyme in the poppy's biosynthetic pathway for morphine. The enzyme turns out to be an unusual protein that contains both cytochrome P-450 and oxidoreductase modules. Together these modules process two subsequent steps in the biosynthetic pathway. The identification of this enzyme may enable alternate routes for morphine biosynthesis that are less dependent on poppy cultivation. Science , this issue p. 309