1UR5

Stabilization of a Tetrameric Malate Dehydrogenase by Introduction of a Disulfide Bridge at the Dimer/Dimer Interface


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Stabilization of a Tetrameric Malate Dehydrogenase by Introduction of a Disulfide Bridge at the Dimer-Dimer Interface

Bjork, A.Dalhus, B.Mantzilas, D.Eijsink, V.G.H.Sirevag, R.

(2003) J Mol Biol 334: 811

  • DOI: 10.1016/j.jmb.2003.10.006
  • Primary Citation of Related Structures:  
    1UR5

  • PubMed Abstract: 
  • Malate dehydrogenase (MDH) from the moderately thermophilic bacterium Chloroflexus aurantiacus (CaMDH) is a tetrameric enzyme, while MDHs from mesophilic organisms usually are dimers. To investigate the potential contribution of the extra dimer-dimer ...

    Malate dehydrogenase (MDH) from the moderately thermophilic bacterium Chloroflexus aurantiacus (CaMDH) is a tetrameric enzyme, while MDHs from mesophilic organisms usually are dimers. To investigate the potential contribution of the extra dimer-dimer interface in CaMDH with respect to thermal stability, we have engineered an intersubunit disulfide bridge designed to strengthen dimer-dimer interactions. The resulting mutant (T187C, containing two 187-187 disulfide bridges in the tetramer) showed a 200-fold increase in half-life at 75 degrees C and an increase of 15 deg. C in apparent melting temperature compared to the wild-type. The crystal structure of the mutant (solved at 1.75 A resolution) was essentially identical with that of the wild-type, with the exception of the added inter-dimer disulfide bridge and the loss of an aromatic intra-dimer contact. Remarkably, the mutant and the wild-type had similar temperature optima and activities at their temperature optima, thus providing a clear case of uncoupling of thermal stability and thermoactivity. The results show that tetramerization may contribute to MDH stability to an extent that depends strongly on the number of stabilizing interactions in the dimer-dimer interface.


    Organizational Affiliation

    Department of Biology, University of Oslo, PO Box 1031 Blindern, N-0316 Oslo, Norway. alexandra.bjork@bio.uio.no



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MALATE DEHYDROGENASEAC309Chloroflexus aurantiacusMutation(s): 1 
EC: 1.1.1.37
Find proteins for P80040 (Chloroflexus aurantiacus (strain ATCC 29366 / DSM 635 / J-10-fl))
Explore P80040 
Go to UniProtKB:  P80040
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAD
Query on NAD

Download CCD File 
A, C
NICOTINAMIDE-ADENINE-DINUCLEOTIDE
C21 H27 N7 O14 P2
BAWFJGJZGIEFAR-NNYOXOHSSA-N
 Ligand Interaction
CD
Query on CD

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A, C
CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

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A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
NA
Query on NA

Download CCD File 
A, C
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.190 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 105.575α = 90
b = 105.575β = 90
c = 102.531γ = 120
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-11-05
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2018-02-07
    Changes: Source and taxonomy