View source for 2o74


==Structure of OHCU decarboxylase in complex with guanine==
<StructureSection load='2o74' size='340' side='right' caption='[[2o74]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2o74]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Brachidanio_rerio Brachidanio rerio]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2O74 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2O74 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GUN:GUANINE'>GUN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2o70|2o70]], [[2o73|2o73]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">zgc:158663 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=7955 Brachidanio rerio])</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=2o74 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2o74 OCA], [http://pdbe.org/2o74 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2o74 RCSB], [http://www.ebi.ac.uk/pdbsum/2o74 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2o74 ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/URAD_DANRE URAD_DANRE]] Catalyzes the stereoselective decarboxylation of 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) to (S)-allantoin. 
== 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/o7/2o74_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=2o74 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The complete degradation of uric acid to (S)-allantoin, as recently elucidated, involves three enzymatic reactions. Inactivation by pseudogenization of the genes of the pathway occurred during hominoid evolution, resulting in a high concentration of urate in the blood and susceptibility to gout. Here, we describe the 1.8A resolution crystal structure of the homodimeric 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase, which catalyzes the last step in the urate degradation pathway, for both ligand-free enzyme and enzyme in complex with the substrate analogs (R)-allantoin and guanine. Each monomer comprises ten alpha-helices, grouped into two domains and assembled in a novel fold. The structure and the mutational analysis of the active site have allowed us to identify some residues that are essential for catalysis, among which His-67 and Glu-87 appear to play a particularly significant role. Glu-87 may facilitate the exit of the carboxylate group because of electrostatic repulsion that destabilizes the ground state of the substrate, whereas His-67 is likely to be involved in a protonation step leading to the stereoselective formation of the (S)-allantoin enantiomer as reaction product. The structural and functional characterization of 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase can provide useful information in view of the potential use of this enzyme in the enzymatic therapy of gout.

The structure of 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase provides insights into the mechanism of uric acid degradation.,Cendron L, Berni R, Folli C, Ramazzina I, Percudani R, Zanotti G J Biol Chem. 2007 Jun 22;282(25):18182-9. Epub 2007 Apr 11. PMID:17428786<ref>PMID:17428786</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2o74" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Brachidanio rerio]]
[[Category: Berni, R]]
[[Category: Cendron, L]]
[[Category: Folli, C]]
[[Category: Percudani, R]]
[[Category: Ramazzina, I]]
[[Category: Zanotti, G]]
[[Category: 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline]]
[[Category: 5-hydroxyisourate]]
[[Category: Decarboxylation]]
[[Category: Hiu]]
[[Category: Lyase]]
[[Category: Ohcu]]