1U0V

An Aldol Switch Discovered in Stilbene Synthases Mediates Cyclization of Specificity of Type III Polyketide Synthases: 18xCHS structure


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.192 

Starting Model: experimental
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This is version 1.5 of the entry. See complete history


Literature

An Aldol Switch Discovered in Stilbene Synthases Mediates Cyclization Specificity of Type III Polyketide Synthases

Austin, M.B.Bowman, M.E.Ferrer, J.-L.Schroder, J.Noel, J.P.

(2004) Chem Biol 11: 1179-1194

  • DOI: https://doi.org/10.1016/j.chembiol.2004.05.024
  • Primary Citation of Related Structures:  
    1U0U, 1U0V, 1U0W

  • PubMed Abstract: 

    Stilbene synthase (STS) and chalcone synthase (CHS) each catalyze the formation of a tetraketide intermediate from a CoA-tethered phenylpropanoid starter and three molecules of malonyl-CoA, but use different cyclization mechanisms to produce distinct chemical scaffolds for a variety of plant natural products. Here we present the first STS crystal structure and identify, by mutagenic conversion of alfalfa CHS into a functional stilbene synthase, the structural basis for the evolution of STS cyclization specificity in type III polyketide synthase (PKS) enzymes. Additional mutagenesis and enzymatic characterization confirms that electronic effects rather than steric factors balance competing cyclization specificities in CHS and STS. Finally, we discuss the problematic in vitro reconstitution of plant stilbenecarboxylate pathways, using insights from existing biomimetic polyketide cyclization studies to generate a novel mechanistic hypothesis to explain stilbenecarboxylate biosynthesis.


  • Organizational Affiliation

    Structural Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Chalcone synthase 2
A, B
393Medicago sativaMutation(s): 18 
Gene Names: CHS2
EC: 2.3.1.74
UniProt
Find proteins for P30074 (Medicago sativa)
Explore P30074 
Go to UniProtKB:  P30074
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP30074
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.192 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.638α = 90
b = 59.753β = 108.17
c = 82.539γ = 90
Software Package:
Software NamePurpose
CNSrefinement
ProDCdata collection
XDSdata scaling
EPMRphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-10-12
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 1.4: 2021-10-27
    Changes: Database references
  • Version 1.5: 2023-08-23
    Changes: Data collection, Refinement description