Download MendeleyA multisubstrate reductase from Plantago major: structure-function in the short chain reductase superfamily.
Fellows, R., Russo, C.M., Silva, C.S., Lee, S.G., Jez, J.M., Chisholm, J.D., Zubieta, C., Nanao, M.H.(2018) Sci Rep 8: 14796-14796
- PubMed: 30287897
- DOI: https://doi.org/10.1038/s41598-018-32967-1
- Primary Citation of Related Structures:
5MLH, 5MLM, 5MLR, 6GSD - PubMed Abstract:
The short chain dehydrogenase/reductase superfamily (SDR) is a large family of NAD(P)H-dependent enzymes found in all kingdoms of life. SDRs are particularly well-represented in plants, playing diverse roles in both primary and secondary metabolism. In addition, some plant SDRs are also able to catalyse a reductive cyclisation reaction critical for the biosynthesis of the iridoid backbone that contains a fused 5 and 6-membered ring scaffold. Mining the EST database of Plantago major, a medicinal plant that makes iridoids, we identified a putative 5β-progesterone reductase gene, PmMOR (P. major multisubstrate oxido-reductase), that is 60% identical to the iridoid synthase gene from Catharanthus roseus. The PmMOR protein was recombinantly expressed and its enzymatic activity assayed against three putative substrates, 8-oxogeranial, citral and progesterone. The enzyme demonstrated promiscuous enzymatic activity and was able to not only reduce progesterone and citral, but also to catalyse the reductive cyclisation of 8-oxogeranial. The crystal structures of PmMOR wild type and PmMOR mutants in complex with NADP + or NAD + and either 8-oxogeranial, citral or progesterone help to reveal the substrate specificity determinants and catalytic machinery of the protein. Site-directed mutagenesis studies were performed and provide a foundation for understanding the promiscuous activity of the enzyme.
Organizational Affiliation:
European Synchrotron Radiation Facility, Structural Biology Group, 71 Avenue des Martyrs, F-38000, Grenoble, France.
