3NOJ

The structure of HMG/CHA aldolase from the protocatechuate degradation pathway of Pseudomonas putida


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.82 Å
  • R-Value Free: 0.171 
  • R-Value Work: 0.159 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural and Kinetic Characterization of 4-Hydroxy-4-methyl-2-oxoglutarate/4-Carboxy-4-hydroxy-2-oxoadipate Aldolase, a Protocatechuate Degradation Enzyme Evolutionarily Convergent with the HpaI and DmpG Pyruvate Aldolases.

Wang, W.Mazurkewich, S.Kimber, M.S.Seah, S.Y.

(2010) J.Biol.Chem. 285: 36608-36615

  • DOI: 10.1074/jbc.M110.159509

  • PubMed Abstract: 
  • 4-Hydroxy-4-methyl-2-oxoglutarate/4-carboxy-4-hydroxy-2-oxoadipate (HMG/CHA) aldolase from Pseudomonas putida F1 catalyzes the last step of the bacterial protocatechuate 4,5-cleavage pathway. The preferred substrates of the enzyme are 2-keto-4-hydrox ...

    4-Hydroxy-4-methyl-2-oxoglutarate/4-carboxy-4-hydroxy-2-oxoadipate (HMG/CHA) aldolase from Pseudomonas putida F1 catalyzes the last step of the bacterial protocatechuate 4,5-cleavage pathway. The preferred substrates of the enzyme are 2-keto-4-hydroxy acids with a 4-carboxylate substitution. The enzyme also exhibits oxaloacetate decarboxylation and pyruvate α-proton exchange activity. Sodium oxalate is a competitive inhibitor of the aldolase reaction. The pH dependence of k(cat)/K(m) and k(cat) for the enzyme is consistent with a single deprotonation with pK(a) values of 8.0 ± 0.1 and 7.0 ± 0.1 for free enzyme and enzyme substrate complex, respectively. The 1.8 Å x-ray structure shows a four-layered α-β-β-α sandwich structure with the active site at the interface of two adjacent subunits of a hexamer; this fold resembles the RNase E inhibitor, RraA, but is novel for an aldolase. The catalytic site contains a magnesium ion ligated by Asp-124 as well as three water molecules bound by Asp-102 and Glu-199'. A pyruvate molecule binds the magnesium ion through both carboxylate and keto oxygen atoms, completing the octahedral geometry. The carbonyl oxygen also forms hydrogen bonds with the guanadinium group of Arg-123, which site-directed mutagenesis confirms is essential for catalysis. A mechanism for HMG/CHA aldolase is proposed on the basis of the structure, kinetics, and previously established features of other aldolase mechanisms.


    Organizational Affiliation

    Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
4-carboxy-4-hydroxy-2-oxoadipate aldolase/oxaloacetate decarboxylase
A
238Pseudomonas putida (strain ATCC 700007 / DSM 6899 / BCRC 17059 / F1)Mutation(s): 0 
EC: 4.1.3.17
Find proteins for A5W059 (Pseudomonas putida (strain ATCC 700007 / DSM 6899 / BCRC 17059 / F1))
Go to UniProtKB:  A5W059
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PYR
Query on PYR

Download SDF File 
Download CCD File 
A
PYRUVIC ACID
C3 H4 O3
LCTONWCANYUPML-UHFFFAOYSA-N
 Ligand Interaction
PG4
Query on PG4

Download SDF File 
Download CCD File 
A
TETRAETHYLENE GLYCOL
C8 H18 O5
UWHCKJMYHZGTIT-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

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Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.82 Å
  • R-Value Free: 0.171 
  • R-Value Work: 0.159 
  • Space Group: H 3 2
Unit Cell:
Length (Å)Angle (°)
a = 111.180α = 90.00
b = 111.180β = 90.00
c = 139.273γ = 120.00
Software Package:
Software NamePurpose
MxDCdata collection
REFMACrefinement
HKL-2000data reduction
PHASERphasing
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-09-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Source and taxonomy, Version format compliance