2UW1

Ivy Desaturase Structure


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.184 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The Crystal Structure of the Ivy {Delta}4-16:0-Acp Desaturase Reveals Structural Details of the Oxidized Active Site and Potential Determinants of Regioselectivity.

Guy, J.E.Whittle, E.Kumaran, D.Lindqvist, Y.Shanklin, J.

(2007) J.Biol.Chem. 282: 19863

  • DOI: 10.1074/jbc.M702520200

  • PubMed Abstract: 
  • The multifunctional acyl-acyl carrier protein (ACP) desaturase from Hedera helix (English ivy) catalyzes the Delta(4) desaturation of 16:0-ACP and the Delta(9) desaturation of 18:0-ACP and further desaturates Delta(9)-16:1 or Delta(9)-18:1 to the cor ...

    The multifunctional acyl-acyl carrier protein (ACP) desaturase from Hedera helix (English ivy) catalyzes the Delta(4) desaturation of 16:0-ACP and the Delta(9) desaturation of 18:0-ACP and further desaturates Delta(9)-16:1 or Delta(9)-18:1 to the corresponding Delta(4,9) dienes. The crystal structure of the enzyme has been solved to 1.95 A resolution, and both the iron-iron distance of approximately 3.2A and the presence of a mu-oxo bridge reveal this to be the only reported structure of a desaturase in the oxidized FeIII-FeIII form. Significant differences are seen between the oxidized active site and the reduced active site of the Ricinus communis (castor) desaturase; His(227) coordination to Fe2 is lost, and the side chain of Glu(224), which bridges the two iron ions in the reduced structure, does not interact with either iron. Although carboxylate shifts have been observed on oxidation of other diiron proteins, this is the first example of the residue moving beyond the coordination range of both iron ions. Comparison of the ivy and castor structures reveal surface amino acids close to the annulus of the substrate-binding cavity and others lining the lower portion of the cavity that are potential determinants of their distinct substrate specificities. We propose a hypothesis that differences in side chain packing explains the apparent paradox that several residues lining the lower portion of the cavity in the ivy desaturase are bulkier than their equivalents in the castor enzyme despite the necessity for the ivy enzyme to accommodate three more carbons beyond the diiron site.


    Organizational Affiliation

    Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PLASTID DELTA4 MULTIFUNCTIONAL ACYL-ACYL CARRIER PROTEIN DESATURASE
A
338N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
PLASTID DELTA4 MULTIFUNCTIONAL ACYL-ACYL CARRIER PROTEIN DESATURASE
B
338N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
A, B
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
GVM
Query on GVM

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Download CCD File 
A, B
(3R)-3-HYDROXY-5,5-DIMETHYLHEXANOIC ACID
C8 H16 O3
PHACRADGRHURFF-LURJTMIESA-N
 Ligand Interaction
FE
Query on FE

Download SDF File 
Download CCD File 
A, B
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.184 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 61.122α = 90.00
b = 61.863β = 90.00
c = 201.002γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-05-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Refinement description, Version format compliance