View source for 1b3b


==THERMOTOGA MARITIMA GLUTAMATE DEHYDROGENASE MUTANT N97D, G376K==
<StructureSection load='1b3b' size='340' side='right'caption='[[1b3b]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1b3b]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B3B OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1B3B 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]] 3.1&#8491;</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=1b3b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1b3b OCA], [https://pdbe.org/1b3b PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1b3b RCSB], [https://www.ebi.ac.uk/pdbsum/1b3b PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1b3b ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DHE3_THEMA DHE3_THEMA] 
== 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/b3/1b3b_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1b3b ConSurf].
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== Publication Abstract from PubMed ==
Comparison of the recently determined three-dimensional structures of several glutamate dehydrogenases allowed for the identification of a five-residue ion-pair network in the hinge region of Pyrococcus furiosus glutamate dehydrogenase (melting temperature 113 degrees C), that is not present in the homologous glutamate dehydrogenase from Thermotoga maritima (melting temperature 93 degrees C). In order to study the role of this ion-pair network, we introduced it into the T. maritima enzyme using a site-directed mutagenesis approach. The resulting T. maritima glutamate dehydrogenases N97D, G376 K and N97D/G376 K as well as the wild-type enzyme were overproduced in Escherichia coli and subsequently purified. Elucidation of the three-dimensional structure of the double mutant N97D/G376 K at 3.0 A, showed that the designed ion-pair interactions were indeed formed. Moreover, because of interactions with an additional charged residue, a six-residue network is present in this double mutant. Melting temperatures of the mutant enzymes N97D, G376 K and N97D/G376 K, as determined by differential scanning calorimetry, did not differ significantly from that of the wild-type enzyme. Identical transition midpoints in guanidinium chloride-induced denaturation experiments were found for the wild-type and all mutant enzymes. Thermal inactivation at 85 degrees C occured more than twofold faster for all mutant enzymes than for the wild-type glutamate dehydrogenase. At temperatures of 65 degrees C and higher, the wild-type and the three mutant enzymes showed identical specific activities. However, at 58 degrees C the specific activity of N97D/G376 K and G376 K was found to be significantly higher than that of the wild-type and N97D enzymes. These results suggest that the engineered ion-pair interactions in the hinge region do not affect the stability towards temperature or guanidinium chloride-induced denaturation but rather affect the specific activity of the enzyme and the temperature at which it functions optimally.

Engineering activity and stability of Thermotoga maritima glutamate dehydrogenase. I. Introduction of a six-residue ion-pair network in the hinge region.,Lebbink JH, Knapp S, van der Oost J, Rice D, Ladenstein R, de Vos WM J Mol Biol. 1998 Jul 10;280(2):287-96. PMID:9654452<ref>PMID:9654452</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Glutamate dehydrogenase 3D structures|Glutamate dehydrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermotoga maritima]]
[[Category: Devos WM]]
[[Category: Knapp S]]
[[Category: Ladenstein R]]
[[Category: Lebbink JHG]]
[[Category: Rice D]]
[[Category: Van Der Oost J]]