View source for 2car


==Crystal Structure Of Human Inosine Triphosphatase==
<StructureSection load='2car' size='340' side='right' caption='[[2car]], [[Resolution|resolution]] 1.09&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2car]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2CAR OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2CAR FirstGlance]. <br>
</td></tr><tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Nucleoside-triphosphate_diphosphatase Nucleoside-triphosphate diphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.1.19 3.6.1.19] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2car FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2car OCA], [http://pdbe.org/2car PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2car RCSB], [http://www.ebi.ac.uk/pdbsum/2car PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2car ProSAT]</span></td></tr>
</table>
== 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/ca/2car_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=2car ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Inosine triphosphatase (ITPA) is a ubiquitous key regulator of cellular non-canonical nucleotide levels. It breaks down inosine and xanthine nucleotides generated by deamination of purine bases. Its enzymatic action prevents accumulation of ITP and reduces the risk of incorporation of potentially mutagenic inosine nucleotides into nucleic acids. Here we describe the crystal structure of human ITPA in complex with its prime substrate ITP, as well as the apoenzyme at 2.8 and 1.1A, respectively. These structures show for the first time the site of substrate and Mg2+ coordination as well as the conformational changes accompanying substrate binding in this class of enzymes. Enzyme substrate interactions induce an extensive closure of the nucleotide binding grove, resulting in tight interactions with the base that explain the high substrate specificity of ITPA for inosine and xanthine over the canonical nucleotides. One of the dimer contact sites is made up by a loop that is involved in coordinating the metal ion in the active site. We predict that the ITPA deficiency mutation P32T leads to a shift of this loop that results in a disturbed affinity for nucleotides and/or a reduced catalytic activity in both monomers of the physiological dimer.

Crystal structure of human inosine triphosphatase. Substrate binding and implication of the inosine triphosphatase deficiency mutation P32T.,Stenmark P, Kursula P, Flodin S, Graslund S, Landry R, Nordlund P, Schuler H J Biol Chem. 2007 Feb 2;282(5):3182-7. Epub 2006 Nov 29. PMID:17138556<ref>PMID:17138556</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 2car" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Nucleoside-triphosphate diphosphatase]]
[[Category: Arrowsmith, C]]
[[Category: Berg, S van den]]
[[Category: Berglund, H]]
[[Category: Edwards, A]]
[[Category: Ehn, M]]
[[Category: Flodin, S]]
[[Category: Flores, A]]
[[Category: Graslund, S]]
[[Category: Hallberg, B M]]
[[Category: Hammarstrom, M]]
[[Category: Hogbom, M]]
[[Category: Kotenyova, T]]
[[Category: Kursula, P]]
[[Category: Nilsson-Ehle, P]]
[[Category: Nordlund, P]]
[[Category: Nyman, T]]
[[Category: Ogg, D]]
[[Category: Persson, C]]
[[Category: Sagemark, J]]
[[Category: Schiavone, L Holmberg]]
[[Category: Schuler, H]]
[[Category: Stenmark, P]]
[[Category: Sundstrom, M]]
[[Category: Thorsell, A G]]
[[Category: Weigelt, J]]
[[Category: Disease mutation]]
[[Category: Hydrolase]]
[[Category: Imp]]
[[Category: Inosine triphosphatase deficiency]]
[[Category: Inosine triphosphate pyrophosphohydrolase]]
[[Category: Itp]]
[[Category: Nucleotide metabolism]]