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Identification of a Flavonoid Glucosyltransferase Involved in 7-OH Site Glycosylation in Tea plants (Camellia sinensis).
- Source :
-
Scientific reports [Sci Rep] 2017 Jul 19; Vol. 7 (1), pp. 5926. Date of Electronic Publication: 2017 Jul 19. - Publication Year :
- 2017
-
Abstract
- Flavonol glycosides, which are often converted from aglycones in a process catalyzed by UDP-glycosyltransferases (UGTs), play an important role for the health of plants and animals. In the present study, a gene encoding a flavonoid 7-O-glycosyltransferase (CsUGT75L12) was identified in tea plants. Recombinant CsUGT75L12 protein displayed glycosyltransferase activity on the 7-OH position of multiple phenolic compounds. In relative comparison to wild-type seeds, the levels of flavonol-glucosides increased in Arabidopsis seeds overexpressing CsUGT75L12. In order to determine the key amino acid residues responsible for the catalytic activity of the protein, a series of site-directed mutagenesis and enzymatic assays were performed based on the 3D structural modeling and docking analyses. These results suggested that residue Q54 is a double binding site that functions as both a sugar receptor and donor. Residues H56 and T151, corresponding to the basic active residues H20 and D119 of VvGT1, were not irreplaceable for CsUGT75L12. In addition, residues Y182, S223, P238, T239, and F240 were demonstrated to be responsible for a 'reversed' sugar receptor binding model. The results of single and triple substitutions confirmed that the function of residues P238, T239, and F240 may substitute or compensate with each other for the flavonoid 7-O-glycosyltransferase activity.
- Subjects :
- Amino Acid Sequence
Arabidopsis enzymology
Arabidopsis genetics
Binding Sites
Escherichia coli metabolism
Glycosylation
Glycosyltransferases chemistry
Glycosyltransferases isolation & purification
Molecular Docking Simulation
Mutagenesis, Site-Directed
Mutant Proteins metabolism
Mutation genetics
Phylogeny
Recombinant Proteins metabolism
Camellia sinensis enzymology
Flavonoids metabolism
Glycosyltransferases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 2045-2322
- Volume :
- 7
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Scientific reports
- Publication Type :
- Academic Journal
- Accession number :
- 28725058
- Full Text :
- https://doi.org/10.1038/s41598-017-06453-z