View source for 4np7


==Structure of phosphotriesterase mutant (S308L/Y309A) from Agrobacterium radiobacter with diethyl thiophosphate bound in the active site==
<StructureSection load='4np7' size='340' side='right'caption='[[4np7]], [[Resolution|resolution]] 1.99&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4np7]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Agrobacterium_tumefaciens Agrobacterium tumefaciens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4NP7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4NP7 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]] 1.99&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO:COBALT+(II)+ION'>CO</scene>, <scene name='pdbligand=DPJ:O,O-DIETHYL+HYDROGEN+THIOPHOSPHATE'>DPJ</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=FE2:FE+(II)+ION'>FE2</scene>, <scene name='pdbligand=KCX:LYSINE+NZ-CARBOXYLIC+ACID'>KCX</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=4np7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4np7 OCA], [https://pdbe.org/4np7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4np7 RCSB], [https://www.ebi.ac.uk/pdbsum/4np7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4np7 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q93LD7_RHIRD Q93LD7_RHIRD] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Phosphotriesterases (PTEs) have been isolated from a range of bacterial species, including Agrobcaterium radiobacter (PTEAr), and are efficient enzymes with broad substrate ranges. The turnover rate of PTEAr for the common organophosphorous insecticide malathion is lower than expected based on its physical properties; principally the pka of its leaving group. In this study, we rationalise the turnover rate of PTEAr for malathion using computational docking of the substrate into a high resolution crystal structure of the enzyme, suggesting that malathion is too large for the PTEAr binding pocket. Protein engineering through combinatorial active site saturation testing (CASTing) was then used to increase the rate of malathion turnover. Variants from a CASTing library in which Ser308 and Tyr309 were mutated yielded variants with increased activity towards malathion. The most active PTEAr variant carried Ser308Leu and Tyr309Ala substitutions, which resulted in a ca. 5000-fold increase in kcat/KM for malathion. X-ray crystal structures for the PTEAr Ser308Leu\Tyr309Ala variant demonstrate that the access to the binding pocket was enhanced by the replacement of the bulky Tyr309 residue with the smaller alanine residue.

A 5000-fold increase in the specificity of a bacterial phosphotriesterase for malathion through combinatorial active site mutagenesis.,Naqvi T, Warden AC, French N, Sugrue E, Carr PD, Jackson CJ, Scott C PLoS One. 2014 Apr 10;9(4):e94177. doi: 10.1371/journal.pone.0094177. eCollection, 2014. PMID:24721933<ref>PMID:24721933</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4np7" style="background-color:#fffaf0;"></div>

==See Also==
*[[Phosphotriesterase 3D structures|Phosphotriesterase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Agrobacterium tumefaciens]]
[[Category: Large Structures]]
[[Category: Carr PD]]
[[Category: Jackson CJ]]
[[Category: Sugrue E]]