View source for 1wk8


==Isoleucyl-tRNA synthetase editing domain complexed with the pre-transfer editing substrate analogue, Val-AMS==
<StructureSection load='1wk8' size='340' side='right'caption='[[1wk8]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1wk8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WK8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1WK8 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]] 1.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=VMS:5O-[N-(L-VALYL)SULPHAMOYL]ADENOSINE'>VMS</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=1wk8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1wk8 OCA], [https://pdbe.org/1wk8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1wk8 RCSB], [https://www.ebi.ac.uk/pdbsum/1wk8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1wk8 ProSAT], [https://www.topsan.org/Proteins/RSGI/1wk8 TOPSAN]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SYI_THET8 SYI_THET8] Catalyzes the attachment of isoleucine to tRNA(Ile). As IleRS can inadvertently accommodate and process structurally similar amino acids such as valine, to avoid such errors it has two additional distinct tRNA(Ile)-dependent editing activities. One activity is designated as 'pretransfer' editing and involves the hydrolysis of activated Val-AMP. The other activity is designated 'posttransfer' editing and involves deacylation of mischarged Val-tRNA(Ile) (By similarity).[HAMAP-Rule:MF_02003]
== 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/wk/1wk8_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=1wk8 ConSurf].
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== Publication Abstract from PubMed ==
In isoleucyl-tRNA synthetase (IleRS), the "editing" domain contributes to accurate aminoacylation by hydrolyzing the mis-synthesized intermediate, valyl-adenylate, in the "pre-transfer" editing mode and the incorrect final product, valyl-tRNA(Ile), in the "post-transfer" editing mode. In the present study, we determined the crystal structures of the Thermus thermophilus IleRS editing domain complexed with the substrate analogues in the pre and post-transfer modes, both at 1.7 A resolution. The active site accommodates the two analogues differently, with the valine side-chain rotated by about 120 degrees and the adenosine moiety oriented upside down. The substrate-binding pocket adjusts to the adenosine-monophosphate and adenosine moieties in the pre and post-transfer modes, respectively, by flipping the Trp227 side-chain by about 180 degrees . The substrate recognition mechanisms of IleRS are characterized by the active-site rearrangement between the two editing modes, and therefore differ from those of the homologous valyl and leucyl-tRNA synthetases from T.thermophilus, in which the post-transfer mode is predominant. Both modes of editing activities were reduced by replacements of Trp227 with Ala, Val, Leu, and His, but not by those with Phe and Tyr, indicating that the aromatic ring of Trp227 is important for the substrate recognition. In both editing modes, Thr233 and His319 recognize the substrate valine side-chain, regardless of the valine side-chain rotation, and reject the isoleucine side-chain. The T233A and H319A mutants have detectable editing activities against the cognate isoleucine.

Structural basis for substrate recognition by the editing domain of isoleucyl-tRNA synthetase.,Fukunaga R, Yokoyama S J Mol Biol. 2006 Jun 16;359(4):901-12. Epub 2006 Apr 25. PMID:16697013<ref>PMID:16697013</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 1wk8" style="background-color:#fffaf0;"></div>

==See Also==
*[[Aminoacyl tRNA synthetase 3D structures|Aminoacyl tRNA synthetase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus thermophilus]]
[[Category: Fukunaga R]]
[[Category: Yokoyama S]]