View source for 1ozq


==CRYSTAL STRUCTURE OF THE MUTATED TRNA-GUANINE TRANSGLYCOSYLASE (TGT)Y106F COMPLEXED WITH PREQ1==
<StructureSection load='1ozq' size='340' side='right'caption='[[1ozq]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ozq]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Zymomonas_mobilis Zymomonas mobilis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OZQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1OZQ 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PRF:7-DEAZA-7-AMINOMETHYL-GUANINE'>PRF</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=1ozq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ozq OCA], [https://pdbe.org/1ozq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ozq RCSB], [https://www.ebi.ac.uk/pdbsum/1ozq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ozq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TGT_ZYMMO TGT_ZYMMO] Exchanges the guanine residue with 7-aminomethyl-7-deazaguanine in tRNAs with GU(N) anticodons (tRNA-Asp, -Asn, -His and -Tyr). After this exchange, a cyclopentendiol moiety is attached to the 7-aminomethyl group of 7-deazaguanine, resulting in the hypermodified nucleoside queuosine (Q) (7-(((4,5-cis-dihydroxy-2-cyclopenten-1-yl)amino)methyl)-7-deazaguanosine).[HAMAP-Rule:MF_00168]
== 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/oz/1ozq_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=1ozq ConSurf].
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== Publication Abstract from PubMed ==
The enzyme tRNA-guanine transglycosylase (TGT, EC 2.4.2.29) catalyses a base-exchange reaction that leads to anticodon modifications of certain tRNAs. The TGT enzymes of the eubacteria Zymomonas mobilis (Z. mobilis TGT) and Escherichia coli (E. coli TGT) show a different behaviour in the presence of competitive inhibitors. The active sites of both enzymes are identical apart from a single conservative amino acid exchange, namely Tyr106 of Z. mobilis TGT is replaced by a Phe in E. coli TGT. Although Tyr106 is, in contrast to Phe106, hydrogen bonded in the ligand-free structure, we can show by a mutational study of TGT(Y106F) that this is not the reason for the different responses upon competition. The TGT enzymes of various species differ in their substrate selectivity. Depending on the applied pH conditions and/or induced by ligand binding, a peptide-bond flip modulates the recognition properties of the substrate binding site, which changes between donor and acceptor functionality. Furthermore interstitial water molecules play an important role in these adaptations of the pocket. The flip of the peptide bond is further stabilised by a glutamate residue that operates as general acid/base. An active-site aspartate residue, presumed to operate as a nucleophile through covalent bonding during the base-exchange reaction, shows different conformations depending on the nature of the bound ligand. The induced-fit adaptations observed in the various TGT complex structures by multiple crystal-structure analyses are in agreement with the functional properties of the enzyme. In consequence, full understanding of this plasticity can be exploited for drug design.

Flexible adaptations in the structure of the tRNA-modifying enzyme tRNA-guanine transglycosylase and their implications for substrate selectivity, reaction mechanism and structure-based drug design.,Brenk R, Stubbs MT, Heine A, Reuter K, Klebe G Chembiochem. 2003 Oct 6;4(10):1066-77. PMID:14523925<ref>PMID:14523925</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 1ozq" style="background-color:#fffaf0;"></div>

==See Also==
*[[TRNA-guanine transglycosylase 3D structures|TRNA-guanine transglycosylase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Zymomonas mobilis]]
[[Category: Brenk R]]
[[Category: Heine A]]
[[Category: Klebe G]]
[[Category: Reuter K]]
[[Category: Stubbs MT]]