2C1X: Structure And Activity Of A Flavonoid 3-O Glucosyltransferase Reveals The Basis For Plant Natural Product Modification

Citation:
Abstract
Glycosylation is a key mechanism for orchestrating the bioactivity, metabolism and location of small molecules in living cells. In plants, a large multigene family of glycosyltransferases is involved in these processes, conjugating hormones, secondary metabolites, biotic and abiotic environmental toxins, to impact directly on cellular homeostasis. The red grape enzyme UDP-glucose:flavonoid 3-O-glycosyltransferase (VvGT1) is responsible for the formation of anthocyanins, the health-promoting compounds which, in planta, function as colourants determining flower and fruit colour and are precursors for the formation of pigmented polymers in red wine. We show that VvGT1 is active, in vitro, on a range of flavonoids. VvGT1 is somewhat promiscuous with respect to donor sugar specificity as dissected through full kinetics on a panel of nine sugar donors. The three-dimensional structure of VvGT1 has also been determined, both in its 'Michaelis' complex with a UDP-glucose-derived donor and the acceptor kaempferol and in complex with UDP and quercetin. These structures, in tandem with kinetic dissection of activity, provide the foundation for understanding the mechanism of these enzymes in small molecule homeostasis.
PDB ID: 2C1XDownload
MMDB ID: 86869
PDB Deposition Date: 2005/9/22
Updated in MMDB: 2010/12
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 2C1X: monomeric; determined by author and by software (PQS)
Molecular Components in 2C1X
Label Count Molecule
Protein (1 molecule)
1
Udp-glucose Flavonoid 3-O Glycosyltransferase
Molecule annotation
Chemicals (2 molecules)
1
1
2
1
* Click molecule labels to explore molecular sequence information.

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