4GUH

1.95 Angstrom Crystal Structure of the Salmonella enterica 3-Dehydroquinate Dehydratase (aroD) E86A Mutant in Complex with Dehydroshikimate (Crystal Form #2)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.193 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Reassessing the type I dehydroquinate dehydratase catalytic triad: Kinetic and structural studies of Glu86 mutants.

Light, S.H.Anderson, W.F.Lavie, A.

(2013) Protein Sci 22: 418-424

  • DOI: 10.1002/pro.2218
  • Primary Citation of Related Structures:  
    4GUF, 4GUG, 4GUH

  • PubMed Abstract: 
  • Dehydroquinate dehydratase (DHQD) catalyzes the third reaction in the biosynthetic shikimate pathway. Type I DHQDs are members of the greater aldolase superfamily, a group of enzymes that contain an active site lysine that forms a Schiff base interme ...

    Dehydroquinate dehydratase (DHQD) catalyzes the third reaction in the biosynthetic shikimate pathway. Type I DHQDs are members of the greater aldolase superfamily, a group of enzymes that contain an active site lysine that forms a Schiff base intermediate. Three residues (Glu86, His143, and Lys170 in the Salmonella enterica DHQD) have previously been proposed to form a triad vital for catalysis. While the roles of Lys170 and His143 are well defined-Lys170 forms the Schiff base with the substrate and His143 shuttles protons in multiple steps in the reaction-the role of Glu86 remains poorly characterized. To probe Glu86's role, Glu86 mutants were generated and subjected to biochemical and structural study. The studies presented here demonstrate that mutant enzymes retain catalytic proficiency, calling into question the previously attributed role of Glu86 in catalysis and suggesting that His143 and Lys170 function as a catalytic dyad. Structures of the Glu86Ala (E86A) mutant in complex with covalently bound reaction intermediate reveal a conformational change of the His143 side chain. This indicates a predominant steric role for Glu86, to maintain the His143 side chain in position consistent with catalysis. The structures also explain why the E86A mutant is optimally active at more acidic conditions than the wild-type enzyme. In addition, a complex with the reaction product reveals a novel, likely nonproductive, binding mode that suggests a mechanism of competitive product inhibition and a potential strategy for the design of therapeutics.


    Organizational Affiliation

    Center for Structural Genomics of Infectious Diseases and Department of Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
3-dehydroquinate dehydrataseAB276Salmonella enterica subsp. enterica serovar Typhimurium str. LT2Mutation(s): 1 
Gene Names: aroDSTM1358
EC: 4.2.1.10
Find proteins for P58687 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore P58687 
Go to UniProtKB:  P58687
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
3DS
Query on 3DS

Download CCD File 
A, B
(4S,5R)-4,5-dihydroxy-3-oxocyclohex-1-ene-1-carboxylic acid
C7 H8 O5
SLWWJZMPHJJOPH-PHDIDXHHSA-N
 Ligand Interaction
NI
Query on NI

Download CCD File 
B
NICKEL (II) ION
Ni
VEQPNABPJHWNSG-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 36.838α = 90
b = 71.671β = 90
c = 171.755γ = 90
Software Package:
Software NamePurpose
Blu-Icedata collection
PHASERphasing
REFMACrefinement
HKL-3000data reduction
HKL-3000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-09-12
    Type: Initial release
  • Version 1.1: 2013-02-06
    Changes: Database references
  • Version 1.2: 2013-04-03
    Changes: Database references
  • Version 1.3: 2017-11-15
    Changes: Refinement description