InterPro domain: IPR045000

This entry represents a group of tropinone reductase-like short-chain dehydrogenases (SDRs) from bacteria and plants. This entry includes tropinone reductase 1/2 (TR1/2) from Datura stramonium (Common thornapple). TR1 catalyses the stereospecific reduction of tropinone to tropine [ 1 ]. The Arabidopsis thaliana homologues show high sequence similarity, but do not reduce tropinone [ 2 ]. One of the Arabidopsis thaliana homologue, SAG13 (At2g29350), has been shown to reduce small lipophilic ketones and several monoterpene ketones [ 3 ]. This entry also includes noroxomaritidine/norcraugsodine reductase (NR) rom Narcissus aff. pseudonarcissus MK-2014 (Daffodil). NR catalyses the conversion of noroxomaritidine to oxomaritidine, a precursor of haemanthamine- and crinamine-type alkaloids, promising anticancer agents [ 4 ].

1. Two tropinone reductases with different stereospecificities are short-chain dehydrogenases evolved from a common ancestor. Proc Natl Acad Sci U S A 90, 9591-5
2. The functional divergence of short-chain dehydrogenases involved in tropinone reduction. Plant J 54, 388-401
3. Substrate flexibility and reaction specificity of tropinone reductase-like short-chain dehydrogenases. Bioorg Chem 53, 37-49
4. Identification of a Noroxomaritidine Reductase with Amaryllidaceae Alkaloid Biosynthesis Related Activities. J Biol Chem 291, 16740-52