View source for 3hzr


==Tryptophanyl-tRNA synthetase homolog from Entamoeba histolytica==
<StructureSection load='3hzr' size='340' side='right'caption='[[3hzr]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3hzr]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Entamoeba_histolytica Entamoeba histolytica]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3HZR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3HZR 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&#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=3hzr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3hzr OCA], [https://pdbe.org/3hzr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3hzr RCSB], [https://www.ebi.ac.uk/pdbsum/3hzr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3hzr ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/C4LUB5_ENTH1 C4LUB5_ENTH1] 
== 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/hz/3hzr_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=3hzr ConSurf].
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== Publication Abstract from PubMed ==
Tryptophanyl-tRNA synthetase (TrpRS) is an essential enzyme that is recognizably conserved across all forms of life. It is responsible for activating and attaching tryptophan to a cognate tRNA(Trp) molecule for use in protein synthesis. In some eukaryotes this original core function has been supplemented or modified through the addition of extra domains or the expression of variant TrpRS isoforms. The three TrpRS structures from pathogenic protozoa described here represent three illustrations of this malleability in eukaryotes. The Cryptosporidium parvum genome contains a single TrpRS gene, which codes for an N-terminal domain of uncertain function in addition to the conserved core TrpRS domains. Sequence analysis indicates that this extra domain, conserved among several apicomplexans, is related to the editing domain of some AlaRS and ThrRS. The C. parvum enzyme remains fully active in charging tRNA(Trp) after truncation of this extra domain. The crystal structure of the active, truncated enzyme is presented here at 2.4A resolution. The Trypanosoma brucei genome contains separate cytosolic and mitochondrial isoforms of TrpRS that have diverged in their respective tRNA recognition domains. The crystal structure of the T. brucei cytosolic isoform is presented here at 2.8A resolution. The Entamoeba histolytica genome contains three sequences that appear to be TrpRS homologs. However one of these, whose structure is presented here at 3.0A resolution, has lost the active site motifs characteristic of the Class I aminoacyl-tRNA synthetase catalytic domain while retaining the conserved features of a fully formed tRNA(Trp) recognition domain. The biological function of this variant E. histolytica TrpRS remains unknown, but, on the basis of a completely conserved tRNA recognition region and evidence for ATP but not tryptophan binding, it is tempting to speculate that it may perform an editing function. Together with a previously reported structure of an unusual TrpRS from Giardia, these protozoan structures broaden our perspective on the extent of structural variation found in eukaryotic TrpRS homologs.

Crystal structures of three protozoan homologs of tryptophanyl-tRNA synthetase.,Merritt EA, Arakaki TL, Gillespie R, Napuli AJ, Kim JE, Buckner FS, Van Voorhis WC, Verlinde CL, Fan E, Zucker F, Hol WG Mol Biochem Parasitol. 2011 May;177(1):20-8. Epub 2011 Jan 19. PMID:21255615<ref>PMID:21255615</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Aminoacyl tRNA synthetase 3D structures|Aminoacyl tRNA synthetase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Entamoeba histolytica]]
[[Category: Large Structures]]
[[Category: Arakaki T]]
[[Category: Merritt EA]]