Structure of UGT78G1 complexed with myricetin and UDP

Experimental Data Snapshot

  • Resolution: 2.10 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.196 

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Crystal structures of glycosyltransferase UGT78G1 reveal the molecular basis for glycosylation and deglycosylation of (iso)flavonoids.

Modolo, L.V.Li, L.Pan, H.Blount, J.W.Dixon, R.A.Wang, X.

(2009) J Mol Biol 392: 1292-1302

  • DOI: https://doi.org/10.1016/j.jmb.2009.08.017
  • Primary Citation of Related Structures:  
    3HBF, 3HBJ

  • PubMed Abstract: 

    The glycosyltransferase UGT78G1 from Medicago truncatula catalyzes the glycosylation of various (iso)flavonoids such as the flavonols kaempferol and myricetin, the isoflavone formononetin, and the anthocyanidins pelargonidin and cyanidin. It also catalyzes a reverse reaction to remove the sugar moiety from glycosides. The structures of UGT78G1 bound with uridine diphosphate or with both uridine diphosphate and myricetin were determined at 2.1 A resolution, revealing detailed interactions between the enzyme and substrates/products and suggesting a distinct binding mode for the acceptor/product. Comparative structural analysis and mutagenesis identify glutamate 192 as a key amino acid for the reverse reaction. This information provides a basis for enzyme engineering to manipulate substrate specificity and to design effective biocatalysts with glycosylation and/or deglycosylation activity.

  • Organizational Affiliation

    Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Flavonoid 3-O-glucosyltransferase454Medicago truncatulaMutation(s): 0 
Gene Names: GT83FUGT78G1
EC: 2.4.1
Find proteins for A6XNC6 (Medicago truncatula)
Explore A6XNC6 
Go to UniProtKB:  A6XNC6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA6XNC6
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on UDP

Download Ideal Coordinates CCD File 
C9 H14 N2 O12 P2
Query on MYC

Download Ideal Coordinates CCD File 
C15 H10 O8
Experimental Data & Validation

Experimental Data

  • Resolution: 2.10 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.196 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 49.166α = 90
b = 77.581β = 96.25
c = 59.554γ = 90
Software Package:
Software NamePurpose
HKL-3000data collection
HKL-3000data reduction
HKL-3000data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-09-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2024-02-21
    Changes: Data collection, Database references, Derived calculations