2gj9

<table><tr><td colspan='2'>[[2gj9]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Ecobd Ecobd]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GJ9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2GJ9 FirstGlance]. <br>

</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=RB:RUBIDIUM+ION'>RB</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">trmE, mnmE, thdF ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=469008 ECOBD])</td></tr>

[[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.

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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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== References ==

<references/>

[[Category: Ecobd]]

[[Category: Scrima, A]]

[[Category: Wittinghofer, A]]

[[Category: Hydrolase]]