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 

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


  • 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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MALATE DEHYDROGENASE
A, C
309Chloroflexus aurantiacus (strain ATCC 29366 / DSM 635 / J-10-fl)Mutation(s): 1 
Gene Names: mdh
EC: 1.1.1.37
Find proteins for P80040 (Chloroflexus aurantiacus (strain ATCC 29366 / DSM 635 / J-10-fl))
Go to UniProtKB:  P80040
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
A, C
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
NAD
Query on NAD

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

Download SDF File 
Download CCD File 
A, C
CADMIUM ION
Cd
WLZRMCYVCSSEQC-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 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 105.575α = 90.00
b = 105.575β = 90.00
c = 102.531γ = 120.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
CNSrefinement
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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