View source for 2gja


==Structure of the MnmE G-domain in complex with GDP*AlF4-, Mg2+ and NH4+==
<StructureSection load='2gja' size='340' side='right'caption='[[2gja]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2gja]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_BL21(DE3) Escherichia coli BL21(DE3)]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GJA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2GJA 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]] 1.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ALF:TETRAFLUOROALUMINATE+ION'>ALF</scene>, <scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NH4:AMMONIUM+ION'>NH4</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=2gja FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2gja OCA], [https://pdbe.org/2gja PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2gja RCSB], [https://www.ebi.ac.uk/pdbsum/2gja PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2gja ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MNME_ECOLI MNME_ECOLI] Exhibits a very high intrinsic GTPase hydrolysis rate. Involved in the addition of a carboxymethylaminomethyl (cmnm) group at the wobble position (U34) of certain tRNAs, forming tRNA-cmnm(5)s(2)U34.
== 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/gj/2gja_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=2gja ConSurf].
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== Publication Abstract from PubMed ==
MnmE, a Guanine nucleotide-binding protein conserved between bacteria and man, is involved in the modification of tRNAs. Here we provide biochemical and X-ray structural evidence for a new GTP-hydrolysis mechanism, where the G-domains of MnmE dimerise in a potassium-dependent manner and induce GTP hydrolysis. The structure in the presence of GDP-AlFx and potassium shows how juxtaposition of the subunits induces a conformational change around the nucleotide which reorients the catalytic machinery. A critical glutamate is positioned such as to stabilise or activate the attacking water. Potassium provides a positive charge into the catalytic site in a position analogous to the arginine finger in the Ras-RasGAP system. Mutational studies show that potassium-dependent dimerisation and GTP hydrolysis can be uncoupled and that interaction between the G-domains is a prerequisite for subsequent phosphoryl transfer. We propose a model for the juxtaposition of G-domains in the full-length protein and how it induces conformational changes in the putative tRNA-modification centre.

Dimerisation-dependent GTPase reaction of MnmE: how potassium acts as GTPase-activating element.,Scrima A, Wittinghofer A EMBO J. 2006 Jun 21;25(12):2940-51. Epub 2006 Jun 8. PMID:16763562<ref>PMID:16763562</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 2gja" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Scrima A]]
[[Category: Wittinghofer A]]