4H6C

Crystal Structure of the Allene Oxide Cyclase 1 from Physcomitrella patens


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.174 
  • R-Value Work: 0.138 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structures of Physcomitrella patens AOC1 and AOC2: Insights into the Enzyme Mechanism and Differences in Substrate Specificity.

Neumann, P.Brodhun, F.Sauer, K.Herrfurth, C.Hamberg, M.Brinkmann, J.Scholz, J.Dickmanns, A.Feussner, I.Ficner, R.

(2012) Plant Physiol. 160: 1251-1266

  • DOI: 10.1104/pp.112.205138
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • In plants, oxylipins regulate developmental processes and defense responses. The first specific step in the biosynthesis of the cyclopentanone class of oxylipins is catalyzed by allene oxide cyclase (AOC) that forms cis(+)-12-oxo-phytodienoic acid. T ...

    In plants, oxylipins regulate developmental processes and defense responses. The first specific step in the biosynthesis of the cyclopentanone class of oxylipins is catalyzed by allene oxide cyclase (AOC) that forms cis(+)-12-oxo-phytodienoic acid. The moss Physcomitrella patens has two AOCs (PpAOC1 and PpAOC2) with different substrate specificities for C₁₈- and C₂₀-derived substrates, respectively. To better understand AOC's catalytic mechanism and to elucidate the structural properties that explain the differences in substrate specificity, we solved and analyzed the crystal structures of 36 monomers of both apo and ligand complexes of PpAOC1 and PpAOC2. From these data, we propose the following intermediates in AOC catalysis: (1) a resting state of the apo enzyme with a closed conformation, (2) a first shallow binding mode, followed by (3) a tight binding of the substrate accompanied by conformational changes in the binding pocket, and (4) initiation of the catalytic cycle by opening of the epoxide ring. As expected, the substrate dihydro analog cis-12,13S-epoxy-9Z,15Z-octadecadienoic acid did not cyclize in the presence of PpAOC1; however, when bound to the enzyme, it underwent isomerization into the corresponding trans-epoxide. By comparing complex structures of the C₁₈ substrate analog with in silico modeling of the C₂₀ substrate analog bound to the enzyme allowed us to identify three major molecular determinants responsible for the different substrate specificities (i.e. larger active site diameter, an elongated cavity of PpAOC2, and two nonidentical residues at the entrance of the active site).


    Organizational Affiliation

    Department of Molecular Structural Biology, Institute of Microbiology and Genetics, University of Goettingen, 37077 Goettingen, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Allene oxide cyclase
A, D, C, B, E, F, G, H, I, J, K, L
195Physcomitrella patens subsp. patensMutation(s): 0 
Gene Names: aoc (aoc1)
EC: 5.3.99.6
Find proteins for Q8GS38 (Physcomitrella patens subsp. patens)
Go to UniProtKB:  Q8GS38
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
A, B, C, D, E, F, G, H, I, J, K, L
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
HEZ
Query on HEZ

Download SDF File 
Download CCD File 
A, B, D, E, F, G
HEXANE-1,6-DIOL
C6 H14 O2
XXMIOPMDWAUFGU-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.174 
  • R-Value Work: 0.138 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 67.321α = 84.61
b = 67.430β = 79.32
c = 161.775γ = 61.99
Software Package:
Software NamePurpose
REFMACrefinement
PHASERphasing
MAR345dtbdata collection
XSCALEdata scaling
XDSdata reduction
PDB_EXTRACTdata extraction
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-10-17
    Type: Initial release
  • Version 1.1: 2012-12-12
    Type: Database references
  • Version 1.2: 2019-09-04
    Type: Data collection