3O7I

Crystal structure of 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase from Klebsiella pneumoniae


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.207 

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This is version 1.1 of the entry. See complete history


Literature

Structural and Mechanistic Studies on Klebsiella pneumoniae 2-Oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline Decarboxylase.

French, J.B.Ealick, S.E.

(2010) J Biol Chem 285: 35446-35454

  • DOI: 10.1074/jbc.M110.156034
  • Primary Citation of Related Structures:  
    3O7K, 3O7H, 3O7I, 3O7J

  • PubMed Abstract: 
  • The stereospecific oxidative degradation of uric acid to (S)-allantoin was recently shown to proceed via three enzymatic steps. The final conversion is a decarboxylation of the unstable intermediate 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and is catalyzed by OHCU decarboxylase ...

    The stereospecific oxidative degradation of uric acid to (S)-allantoin was recently shown to proceed via three enzymatic steps. The final conversion is a decarboxylation of the unstable intermediate 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and is catalyzed by OHCU decarboxylase. Here we present the structures of Klebsiella pneumoniae OHCU decarboxylase in unliganded form and with bound allantoin. These structures provide evidence that ligand binding organizes the active site residues for catalysis. Modeling of the substrate and intermediates provides additional support for this hypothesis. In addition we characterize the steady state kinetics of this enzyme and report the first OHCU decarboxylase inhibitor, allopurinol, a structural isomer of hypoxanthine. This molecule is a competitive inhibitor of K. pneumoniae OHCU decarboxylase with a K(i) of 30 ± 2 μM. Circular dichroism measurements confirm structural observations that this inhibitor disrupts the necessary organization of the active site. Our structural and biochemical studies also provide further insights into the mechanism of catalysis of OHCU decarboxylation.


    Organizational Affiliation

    Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
OHCU decarboxylaseA, B189Klebsiella pneumoniae subsp. pneumoniae MGH 78578Mutation(s): 0 
Gene Names: KPN78578_16350KPN_01665
Find proteins for A6T925 (Klebsiella pneumoniae subsp. pneumoniae (strain ATCC 700721 / MGH 78578))
Explore A6T925 
Go to UniProtKB:  A6T925
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.207 
  • Space Group: P 41
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 88.179α = 90
b = 88.179β = 90
c = 40.217γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-09-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance