View source for 1it8


==Crystal structure of archaeosine tRNA-guanine transglycosylase from Pyrococcus horikoshii complexed with archaeosine precursor, preQ0==
<StructureSection load='1it8' size='340' side='right'caption='[[1it8]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1it8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IT8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1IT8 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PQ0:2-AMINO-4-OXO-4,7-DIHYDRO-3H-PYRROLO[2,3-D]PYRIMIDINE-5-CARBONITRILE'>PQ0</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=1it8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1it8 OCA], [https://pdbe.org/1it8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1it8 RCSB], [https://www.ebi.ac.uk/pdbsum/1it8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1it8 ProSAT], [https://www.topsan.org/Proteins/RSGI/1it8 TOPSAN]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ATGT_PYRHO ATGT_PYRHO] Exchanges the guanine residue with 7-cyano-7-deazaguanine (preQ0) at position 15 in the dihydrouridine loop (D-loop) of archaeal tRNAs.[HAMAP-Rule:MF_01634]
== 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/it/1it8_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=1it8 ConSurf].
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== Publication Abstract from PubMed ==
Archaeosine tRNA-guanine transglycosylase (ArcTGT) catalyzes the exchange of guanine at position 15 in the D-loop of archaeal tRNAs with a free 7-cyano-7-deazaguanine (preQ(0)) base, as the first step in the biosynthesis of an archaea-specific modified base, archaeosine (7-formamidino-7-deazaguanosine). We determined the crystal structures of ArcTGT from Pyrococcus horikoshii at 2.2 A resolution and its complexes with guanine and preQ(0), at 2.3 and 2.5 A resolutions, respectively. The N-terminal catalytic domain folds into an (alpha/beta)(8) barrel with a characteristic zinc-binding site, showing structural similarity with that of the bacterial queuosine TGT (QueTGT), which is involved in queuosine (7-[[(4,5-cis-dihydroxy-2-cyclopenten-1-yl)-amino]methyl]-7-deazaguanosine ) biosynthesis and targets the tRNA anticodon. ArcTGT forms a dimer, involving the zinc-binding site and the ArcTGT-specific C-terminal domain. The C-terminal domains have novel folds, including an OB fold-like "PUA domain", whose sequence is widely conserved in eukaryotic and archaeal RNA modification enzymes. Therefore, the C-terminal domains may be involved in tRNA recognition. In the free-form structure of ArcTGT, an alpha-helix located at the rim of the (alpha/beta)(8) barrel structure is completely disordered, while it is ordered in the guanine-bound and preQ(0)-bound forms. Structural comparison of the ArcTGT.preQ(0), ArcTGT.guanine, and QueTGT.preQ(1) complexes provides novel insights into the substrate recognition mechanisms of ArcTGT.

Crystal structure of archaeosine tRNA-guanine transglycosylase.,Ishitani R, Nureki O, Fukai S, Kijimoto T, Nameki N, Watanabe M, Kondo H, Sekine M, Okada N, Nishimura S, Yokoyama S J Mol Biol. 2002 May 3;318(3):665-77. PMID:12054814<ref>PMID:12054814</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 1it8" 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: Pyrococcus horikoshii]]
[[Category: Fukai S]]
[[Category: Ishitani R]]
[[Category: Kijimoto T]]
[[Category: Kondo H]]
[[Category: Nameki N]]
[[Category: Nishimura S]]
[[Category: Nureki O]]
[[Category: Okada N]]
[[Category: Sekine M]]
[[Category: Watanabe M]]
[[Category: Yokoyama S]]