View source for 1ur5


==Stabilization of a Tetrameric Malate Dehydrogenase by Introduction of a Disulfide Bridge at the Dimer/Dimer Interface==
<StructureSection load='1ur5' size='340' side='right'caption='[[1ur5]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ur5]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Chloroflexus_aurantiacus Chloroflexus aurantiacus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UR5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1UR5 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.75&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CD:CADMIUM+ION'>CD</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1ur5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ur5 OCA], [https://pdbe.org/1ur5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ur5 RCSB], [https://www.ebi.ac.uk/pdbsum/1ur5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ur5 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MDH_CHLAA MDH_CHLAA] Catalyzes the reversible oxidation of malate to oxaloacetate.[HAMAP-Rule:MF_00487]
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ur/1ur5_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1ur5 ConSurf].
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== Publication Abstract from PubMed ==
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.

Stabilization of a tetrameric malate dehydrogenase by introduction of a disulfide bridge at the dimer-dimer interface.,Bjork A, Dalhus B, Mantzilas D, Eijsink VG, Sirevag R J Mol Biol. 2003 Dec 5;334(4):811-21. PMID:14636605<ref>PMID:14636605</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1ur5" style="background-color:#fffaf0;"></div>

==See Also==
*[[Malate Dehydrogenase 3D structures|Malate Dehydrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Chloroflexus aurantiacus]]
[[Category: Large Structures]]
[[Category: Bjork A]]
[[Category: Dalhus B]]
[[Category: Eijsink VGH]]
[[Category: Mantzilas D]]
[[Category: Sirevag R]]