title: Cloning and expression of UDP-glucose: flavonoid 7-O-glucosyltransferase from hairy root cultures of Scutellaria baicalensis.
abstract: A cDNA encoding UDP-glucose: baicalein 7-O-glucosyltransferase (UBGT) was isolated from a cDNA library from hairy root cultures of Scutellaria baicalensis Georgi probed with a partial-length cDNA clone of a UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) from grape (Vitis vinifera L.). The heterologous probe contained a glucosyltransferase consensus amino acid sequence which was also present in the Scutellaria cDNA clones. The complete nucleotide sequence of the 1688-bp cDNA insert was determined and the deduced amino acid sequences are presented. The nucleotide sequence analysis of UBGT revealed an open reading frame encoding a polypeptide of 476 amino acids with a calculated molecular mass of 53,094 Da. The reaction product for baicalein and UDP-glucose catalyzed by recombinant UBGT in Escherichia coli was identified as authentic baicalein 7-O-glucoside using high-performance liquid chromatography and proton nuclear magnetic resonance spectroscopy. The enzyme activities of recombinant UBGT expressed in E. coli were also detected towards flavonoids such as baicalein, wogonin, apigenin, scutellarein, 7,4'-dihydroxyflavone and kaempferol, and phenolic compounds. The accumulation of UBGT mRNA in hairy roots was in response to wounding or salicylic acid treatments.
authors.affiliation: School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan. hirotanim@pharm.kitasato-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Hirotani
authors.forename: R
authors.initials: R
authors.lastname: Kuroda
authors.forename: H
authors.initials: H
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Yoshikawa
mesh_terms: D000595:Amino Acid Sequence; D015152:Blotting, Northern; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005419:Flavonoids / Q000378:metabolism*; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D019686:Lamiaceae / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010802:Phylogeny; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D005419:Flavonoids; D011994:Recombinant Proteins; D005964:Glucosyltransferases; C417581:UDP-glucose baicalein 7-O-glucosyltransferase; C023249:flavonol 3-O-glucosyltransferase