1H1I

CRYSTAL STRUCTURE OF QUERCETIN 2,3-DIOXYGENASE ANAEROBICALLY COMPLEXED WITH THE SUBSTRATE QUERCETN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.183 
  • R-Value Work: 0.148 
  • R-Value Observed: 0.150 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Anaerobic Enzyme.Substrate Structures Provide Insight Into the Reaction Mechanism of the Copper- Dependent Quercetin 2,3-Dioxygenase.

Steiner, R.A.Kalk, K.H.Dijkstra, B.W.

(2002) Proc Natl Acad Sci U S A 99: 16625

  • DOI: 10.1073/pnas.262506299
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Quercetin 2,3-dioxygenase (2,3QD) is the only firmly established copper dioxygenase known so far. Depending solely on a mononuclear Cu center, it catalyzes the breakage of the O-heterocycle of flavonols, producing more easily degradable phenolic carb ...

    Quercetin 2,3-dioxygenase (2,3QD) is the only firmly established copper dioxygenase known so far. Depending solely on a mononuclear Cu center, it catalyzes the breakage of the O-heterocycle of flavonols, producing more easily degradable phenolic carboxylic acid ester derivatives. In the enzymatic process, two CC bonds are broken and concomitantly carbon monoxide is released. The x-ray structures of Aspergillus japonicus 2,3QD anaerobically complexed with the substrate kaempferol and the natural substrate quercetin have been determined at 1.90- and 1.75-A resolution, respectively. Flavonols coordinate to the copper ion as monodentate ligands through their 3OH group. They occupy a shallow and overall hydrophobic cavity proximal to the metal center. As a result of a van der Waals contact between the most outward flavonol A-ring and Pro(164), a flexible loop in front of the active site becomes partly ordered. Interestingly, flavonols bound to 2,3QD are bent at the C2 atom, which is pyramidalized. The increased local sp(3) character at this atom may stabilize a carbon-centered radical activated for dioxygen attack. Glu(73) coordinates the copper through its O epsilon 1 atom. The short distance of about 2.55 A between its O epsilon 2 atom and the flavonol O3 atom suggests that a hydrogen bond exists between the two atoms, indicating that Glu(73) can act as a base in flavonol deprotonation and that it retains the proton. Structure-based geometric considerations indicate O(2) binding to the flavonol C2 atom as the preferred route for flavonol dioxygenation.


    Organizational Affiliation

    Laboratory of Biophysical Chemistry, Department of Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
QUERCETIN 2,3-DIOXYGENASE
A, B, C, D
350Aspergillus japonicusMutation(s): 0 
EC: 1.13.11.24
Find proteins for Q7SIC2 (Aspergillus japonicus)
Go to UniProtKB:  Q7SIC2
Protein Feature View
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
QUE
Query on QUE

Download CCD File 
A, B, C, D
3,5,7,3',4'-PENTAHYDROXYFLAVONE
C15 H10 O7
REFJWTPEDVJJIY-UHFFFAOYSA-N
 Ligand Interaction
NAG
Query on NAG

Download CCD File 
A, B, C, D
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
MPD
Query on MPD

Download CCD File 
A, B, C
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
 Ligand Interaction
CU
Query on CU

Download CCD File 
A, B, C, D
COPPER (II) ION
Cu
JPVYNHNXODAKFH-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.183 
  • R-Value Work: 0.148 
  • R-Value Observed: 0.150 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 109.298α = 90
b = 55.745β = 98.39
c = 124.163γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-11-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.2: 2019-05-08
    Changes: Data collection, Derived calculations, Experimental preparation, Other