Characterization of flavonoid 7-O-glucosyltransferase from Arabidopsis thaliana

Biosci Biotechnol Biochem. 2006 Jun;70(6):1471-7. doi: 10.1271/bbb.60006.


Most flavonoids found in plants exist as glycosides, and glycosylation status has a wide range of effects on flavonoid solubility, stability, and bioavailability. Glycosylation of flavonoids is mediated by Family 1 glycosyltransferases (UGTs), which use UDP-sugars, such as UDP-glucose, as the glycosyl donor. AtGT-2, a UGT from Arabidopsis thaliana, was cloned and expressed in Escherichia coli as a gluthatione S-transferase fusion protein. Several compounds, including flavonoids, were tested as potential substrates. HPLC analysis of the reaction products indicated that AtGT-2 transfers a glucose molecule into several different kinds of flavonoids, eriodictyol being the most effective substrate, followed by luteolin, kaempferol, and quercetin. Based on comparison of HPLC retention times with authentic flavonoid 7-O-glucosides and nuclear magnetic resonance spectroscopy, the glycosylation position in the reacted flavonoids was determined to be the C-7 hydroxyl group. These results indicate that AtGT-2 encodes a flavonoid 7-O-glucosyltransferase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Cloning, Molecular
  • Conserved Sequence
  • Flavonoids / chemistry
  • Flavonoids / metabolism
  • Gene Expression
  • Glucosyltransferases / chemistry
  • Glucosyltransferases / genetics
  • Glucosyltransferases / isolation & purification
  • Glucosyltransferases / metabolism*
  • Molecular Sequence Data
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Substrate Specificity


  • Flavonoids
  • Recombinant Proteins
  • Glucosyltransferases
  • flavone 7-O-beta-glucosyltransferase

Associated data

  • GENBANK/AY090273