title: Identification of cDNAs encoding pterocarpan reductase involved in isoflavan phytoalexin biosynthesis in Lotus japonicus by EST mining.
abstract: Isoflavans and pterocarpans are the major biosynthetically connected phytoalexins in legumes. A search of the expressed sequence tag library of a model legume Lotus japonicus, which produces an (-)-isoflavan, for homologs of phenylcoumaran benzylic ether reductase catalyzing the reductive cleavage of dihydrofurans, yielded seven full-length cDNAs, and the encoded proteins were analyzed in vitro. Four of them cleaved the dihydrofuran of a pterocarpan medicarpin to yield an isoflavan (-)-vestitol and were designated pterocarpan reductase (PTR). Two PTRs displayed enantiospecificity to (-)-medicarpin, representing genuine L. japonicus PTRs, while the other two lacked enantiospecificity and were presumed to be evolutionarily primitive types.
authors.affiliation: Department of Applied Biological Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan. akashi@brs.nihon-u.ac.jp
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Akashi
authors.forename: Shoko
authors.initials: S
authors.lastname: Koshimizu
authors.forename: Toshio
authors.initials: T
authors.lastname: Aoki
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Ayabe
mesh_terms: D018076:DNA, Complementary / Q000235:genetics* / Q000302:isolation & purification; D030561:Databases, Nucleic Acid; D020224:Expressed Sequence Tags; D005419:Flavonoids / Q000096:biosynthesis* / Q000737:chemistry; D005978:Glutathione / Q000378:metabolism; D000070116:Lotus / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010802:Phylogeny; D036343:Pterocarpans / Q000737:chemistry / Q000378:metabolism*; D036226:Seedlings / Q000201:enzymology; D012717:Sesquiterpenes; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism*; D000094162:Phytoalexins
chemical_list: D018076:DNA, Complementary; D005419:Flavonoids; D036343:Pterocarpans; D012717:Sesquiterpenes; D013729:Terpenes; D010088:Oxidoreductases; D005978:Glutathione; C515147:vestitol; D000094162:Phytoalexins