2BRJ

X-ray structure of the Allene Oxide Cyclase from Arabidopsis thaliana


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.174 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The Crystal Structure of Arabidopsis Thaliana Allene Oxide Cyclase: Insights Into the Oxylipin Cyclization Reaction.

Hofmann, E.Zerbe, P.Schaller, F.

(2006) Plant Cell 18: 3201

  • DOI: 10.1105/tpc.106.043984
  • Primary Citation of Related Structures:  
    2BRJ, 2DIO, 2GIN

  • PubMed Abstract: 
  • We describe the crystallization and structure elucidation of Arabidopsis thaliana allene oxide cyclase 2 (AOC2), a key enzyme in the biosynthesis of jasmonates. In a coupled reaction with allene oxide synthase, AOC2 releases the first cyclic and biologically active metabolite, 12-oxo-phytodienoic acid (OPDA) ...

    We describe the crystallization and structure elucidation of Arabidopsis thaliana allene oxide cyclase 2 (AOC2), a key enzyme in the biosynthesis of jasmonates. In a coupled reaction with allene oxide synthase, AOC2 releases the first cyclic and biologically active metabolite, 12-oxo-phytodienoic acid (OPDA). AOC2 (AT3G25770) folds into an eight-stranded antiparallel beta-barrel with a C-terminal partial helical extension. The protein forms a hydrophobic binding cavity with two distinct polar patches. AOC2 is trimeric in crystals, in vitro and in planta. Based on the observed folding pattern, we assigned AOC2 as a low molecular weight member of the lipocalin family with enzymatic activity in plants. We determined the binding position of the competitive inhibitor vernolic acid (a substrate analog) in the binding pocket. Based on models for bound substrate 12,13-epoxy-9,11,15-octadecatrienoic acid and product OPDA, we propose a reaction scheme that explains the influence of the C15 double bond on reactivity. Reaction is promoted by anchimeric assistance through a conserved Glu residue. The transition state with a pentadienyl carbocation and an oxyanion is stabilized by a strongly bound water molecule and favorable pi-pi interactions with aromatic residues in the cavity. Stereoselectivity results from steric restrictions to the necessary substrate isomerizations imposed by the protein.


    Organizational Affiliation

    Lehrstuhl für Biophysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany. eckhard.hofmann@bph.rub.de



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ARABIDOPSIS THALIANA GENOMIC DNA, CHROMOSOME 3,A, B, C188Arabidopsis thalianaMutation(s): 0 
Gene Names: AOC2At3g25770K13N2.11K13N2_9
EC: 5.3.99.6
Membrane Entity: Yes 
UniProt
Find proteins for Q9LS02 (Arabidopsis thaliana)
Explore Q9LS02 
Go to UniProtKB:  Q9LS02
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9LS02
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A],
F [auth C]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, C L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.174 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 64.48α = 90
b = 99.95β = 90
c = 106.15γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XSCALEdata scaling
HKL2MAPphasing
SHELXDphasing
SHELXEphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-08-24
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2019-05-08
    Changes: Data collection, Derived calculations, Experimental preparation, Other