1EC9

E. COLI GLUCARATE DEHYDRATASE BOUND TO XYLAROHYDROXAMATE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.179 

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Ligand Structure Quality Assessment 


This is version 1.6 of the entry. See complete history


Literature

Evolution of enzymatic activities in the enolase superfamily: crystallographic and mutagenesis studies of the reaction catalyzed by D-glucarate dehydratase from Escherichia coli.

Gulick, A.M.Hubbard, B.K.Gerlt, J.A.Rayment, I.

(2000) Biochemistry 39: 4590-4602

  • DOI: https://doi.org/10.1021/bi992782i
  • Primary Citation of Related Structures:  
    1EC7, 1EC8, 1EC9, 1ECQ

  • PubMed Abstract: 

    D-Glucarate dehydratase (GlucD) from Escherichia coli catalyzes the dehydration of both D-glucarate and L-idarate as well as their interconversion via epimerization. GlucD is a member of the mandelate racemase (MR) subgroup of the enolase superfamily, the members of which catalyze reactions that are initiated by abstraction of the alpha-proton of a carboxylate anion substrate. Alignment of the sequence of GlucD with that of MR reveals a conserved Lys-X-Lys motif and a His-Asp dyad homologous to the S- and R-specific bases in the active site of MR. Crystals of GlucD have been obtained into which the substrate D-glucarate and two competitive inhibitors, 4-deoxy-D-glucarate and xylarohydroxamate, could be diffused; D-glucarate is converted to the dehydration product, 5-keto-4-deoxy-D-glucarate (KDG). The structures of these complexes have been determined and reveal the identities of the ligands for the required Mg(2+) (Asp(235), Glu(266), and Asn(289)) as well as confirm the expected presence of Lys(207) and His(339), the catalytic bases that are properly positioned to abstract the proton from C5 of L-idarate and D-glucarate, respectively. Surprisingly, the C6 carboxylate group of KDG is a bidentate ligand to the Mg(2+), with the resulting geometry of the bound KDG suggesting that stereochemical roles of Lys(207) and His(339) are reversed from the predictions made on the basis of the established structure-function relationships for the MR-catalyzed reaction. The catalytic roles of these residues have been examined by characterization of mutant enzymes, although we were unable to use these to demonstrate the catalytic independence of Lys(207) and His(339) as was possible for the homologous Lys(166) and His(297) in the MR-catalyzed reaction.


  • Organizational Affiliation

    Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53705, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
GLUCARATE DEHYDRATASE
A, B, C, D
446Escherichia coliMutation(s): 0 
EC: 4.2.1.40
UniProt
Find proteins for P0AES2 (Escherichia coli (strain K12))
Explore P0AES2 
Go to UniProtKB:  P0AES2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0AES2
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
XYH
Query on XYH

Download Ideal Coordinates CCD File 
F [auth A],
J [auth B],
M [auth C],
O [auth D]
XYLAROHYDROXAMATE
C5 H8 N O7
DMGBHBFPSRKPBV-XZIMBLGRSA-M
IPA
Query on IPA

Download Ideal Coordinates CCD File 
G [auth A],
H [auth A],
K [auth B],
P [auth D]
ISOPROPYL ALCOHOL
C3 H8 O
KFZMGEQAYNKOFK-UHFFFAOYSA-N
MG
Query on MG

Download Ideal Coordinates CCD File 
E [auth A],
I [auth B],
L [auth C],
N [auth D]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
XYH PDBBind:  1EC9 Ki: 8.00e+5 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.179 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.294α = 103.14
b = 84.836β = 94.31
c = 98.987γ = 113.2
Software Package:
Software NamePurpose
AMoREphasing
TNTrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2000-05-23
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2018-01-31
    Changes: Experimental preparation
  • Version 1.4: 2018-02-28
    Changes: Experimental preparation
  • Version 1.5: 2024-02-07
    Changes: Data collection, Database references, Derived calculations
  • Version 1.6: 2024-03-13
    Changes: Source and taxonomy, Structure summary