Tropinone reductase II (TR-II)

Tropinone reductase II is an enzyme found in higher plants, especially in species that produce tropane alkaloids. It catalyzes the NADPH-dependent stereoselective reduction of the carbonyl group of tropinone to form pseudotropine. This reaction diverts the metabolic flux toward the biosynthesis of calystegine alkaloids, in contrast to tropinone reductase I, which leads to the synthesis of tropine and subsequently hyoscyamine and scopolamine. Structurally, tropinone reductase II is part of the short-chain dehydrogenase/reductase (SDR) family and adopts a Rossmann-fold for NADP(H) binding. The enzyme plays a key metabolic role in the diversification of tropane alkaloids in plants, but it is not a direct therapeutic target for any approved drug nor has direct disease relevance in humans. It is, however, increasingly important for metabolic engineering approaches to the industrial production of bioactive natural products and drugs in medicinal plants

Other names

Pseudotropine-forming tropinone reductaseTropinone reductase 2TR-IITropinone reductase (when referring to II specifically)

NADPH-dependent reduction of tropinone to pseudotropine