Qingyan Meng, Syed G A Moinuddin, Rhodesia M Celoy, Clyde A Smith, Robert P Young, Michael A Costa, Rachel A Freeman, Masashi Fukaya, Doo Nam Kim, John R Cort, Martha C Hawes, Hans D van Etten, Pankaj Pandey, Amar G Chittiboyina, Daneel Ferreira, Laurence B Davin, Norman G Lewis
Pea phytoalexins (-)-maackiain and (+)-pisatin have opposite C6a/C11a configurations, but biosynthetically how this occurs is unknown. Pea dirigent-protein (DP) PsPTS2 generates 7,2'-dihydroxy-4',5'-methylenedioxyisoflav-3-ene (DMDIF), and stereoselectivity towards four possible 7,2'-dihydroxy-4',5'-methylenedioxyisoflavan-4-ol (DMDI) stereoisomers was investigated. Stereoisomer configurations were determined using NMR spectroscopy, electronic circular dichroism, and molecular orbital analyses. PsPTS2 efficiently converted cis-(3R,4R)-DMDI into DMDIF 20-fold faster than the trans-(3R,4S)-isomer...
January 12, 2024: Journal of Biological Chemistry