View source for 1hgx


==HYPOXANTHINE-GUANINE-XANTHINE PHOSPHORIBOSYLTRANSFERASE (HGXPRTASE)==
<StructureSection load='1hgx' size='340' side='right'caption='[[1hgx]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1hgx]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Tritrichomonas_suis Tritrichomonas suis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HGX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1HGX 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=5GP:GUANOSINE-5-MONOPHOSPHATE'>5GP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1hgx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hgx OCA], [https://pdbe.org/1hgx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1hgx RCSB], [https://www.ebi.ac.uk/pdbsum/1hgx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1hgx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HGXR_TRIFO HGXR_TRIFO] Essential in nucleic acid metabolism of T.foetus because the parasite is unable to synthesize purine nucleotides de novo and relies on the HGXPRTase activities for its purine requirements by salvaging purine bases from the host. Works with guanine, hypoxanthine and xanthine.
== 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/hg/1hgx_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1hgx ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The crystal structure of the hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) from Tritrichomonas foetus has been determined and refined against X-ray data to 1.9 A resolution. T. foetus HGXPRTase crystallizes as an asymmetric dimer, with GMP bound to only one of the two molecules that form the asymmetric unit. Each molecule of HGXPRTase is formed by two lobes joined by a short "hinge" region, and the GMP binds in a cavity between the two lobes. A comparison of the two molecules in the asymmetric unit shows that the hinge region is flexible and that ligand binding affects the relative positions of the two lobes. The binding of GMP brings the two lobes closer together, rotating one lobe by about 5 degrees relative to the other. T. foetus appears to depend on HGXPRTase for its supply of GMP, making this enzyme a target for antiparasite drug design. A comparison of the structures of T. foetus HGXPRTase and human HGPRTase reveals that, while these enzymes retain a similar polypeptide fold, there are substantial differences between the active sites of these two homologs. These differences suggest that it will be possible to find compounds that selectively inhibit the parasite enzyme.

Crystal structure of the hypoxanthine-guanine-xanthine phosphoribosyltransferase from the protozoan parasite Tritrichomonas foetus.,Somoza JR, Chin MS, Focia PJ, Wang CC, Fletterick RJ Biochemistry. 1996 Jun 4;35(22):7032-40. PMID:8679528<ref>PMID:8679528</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1hgx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Phosphoribosyltransferase 3D structures|Phosphoribosyltransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Tritrichomonas suis]]
[[Category: Fletterick RJ]]
[[Category: Somoza JR]]
[[Category: Wang CC]]