View source for 4rhq


==Crystal structure of T. brucei arginase-like protein double mutant S149D/S153D==
<StructureSection load='4rhq' size='340' side='right'caption='[[4rhq]], [[Resolution|resolution]] 2.18&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4rhq]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Trypanosoma_brucei_brucei_TREU927 Trypanosoma brucei brucei TREU927]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4RHQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4RHQ 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]] 2.18&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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=4rhq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4rhq OCA], [https://pdbe.org/4rhq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4rhq RCSB], [https://www.ebi.ac.uk/pdbsum/4rhq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4rhq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q581Y0_TRYB2 Q581Y0_TRYB2] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The X-ray crystal structure of an arginase-like protein from the parasitic protozoan Trypanosoma brucei, designated TbARG, is reported at 1.80 and 2.38 A resolution in its reduced and oxidized forms, respectively. The oxidized form of TbARG is a disulfide-linked hexamer that retains the overall architecture of a dimer of trimers in the reduced form. Intriguingly, TbARG does not contain metal ions in its putative active site, and amino acid sequence comparisons indicate that all but one of the residues required for coordination to the catalytically obligatory binuclear manganese cluster in other arginases are substituted here with residues incapable of metal ion coordination. Therefore, the structure of TbARG is the first of a member of the arginase/deacetylase superfamily that is not a metalloprotein. Although we show that metal binding activity is easily reconstituted in TbARG by site-directed mutagenesis and confirmed in X-ray crystal structures, it is curious that this protein and its parasitic orthologues evolved away from metal binding function. Knockout of the TbARG gene from the genome demonstrated that its function is not essential to cultured bloodstream-form T. brucei, and metabolomics analysis confirmed that the enzyme has no role in the conversion of l-arginine to l-ornithine in these cells. While the molecular function of TbARG remains enigmatic, the fact that the T. brucei genome encodes only this protein and not a functional arginase indicates that the parasite must import l-ornithine from its host to provide a source of substrate for ornithine decarboxylase in the polyamine biosynthetic pathway, an active target for the development of antiparasitic drugs.

Crystal Structure of an Arginase-like Protein from Trypanosoma brucei That Evolved without a Binuclear Manganese Cluster.,Hai Y, Kerkhoven EJ, Barrett MP, Christianson DW Biochemistry. 2014 Dec 23. PMID:25536859<ref>PMID:25536859</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4rhq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Arginase 3D structures|Arginase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Trypanosoma brucei brucei TREU927]]
[[Category: Barrett MP]]
[[Category: Christianson DW]]
[[Category: Hai Y]]