View source for 2iax


==Crystal structure of squid ganglion DFPase D232S mutant==
<StructureSection load='2iax' size='340' side='right'caption='[[2iax]], [[Resolution|resolution]] 1.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2iax]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Loligo_vulgaris Loligo vulgaris]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IAX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2IAX 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]] 1.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</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=2iax FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2iax OCA], [https://pdbe.org/2iax PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2iax RCSB], [https://www.ebi.ac.uk/pdbsum/2iax PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2iax ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DFPA_LOLVU DFPA_LOLVU] Biological function and substrate unknown. However, it is capable of acting on phosphorus anhydride bonds (such as phosphorus-halide and phosphorus-cyanide) in organophosphorus compounds (including nerve gases).<ref>PMID:15966726</ref> 
== 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/ia/2iax_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=2iax ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The active site, the substrate binding site, and the metal binding sites of the diisopropylfluorophosphatase (DFPase) from Loligo vulgaris have been modified by means of site-directed mutagenesis to improve our understanding of the reaction mechanism. Enzymatic characterization of mutants located in the major groove of the substrate binding pocket indicates that large hydrophobic side chains at these positions are favorable for substrate turnover. Moreover, the active site residue His287 proved to be beneficial, but not essential, for DFP hydrolysis. In most cases, hydrophobic side chains at position 287 led to significant catalytic activities although reduced relative to the wild-type enzyme. With respect to the Ca-1 binding site, where catalysis occurs, various mutants indicated that the net charge at this calcium-binding site as well as the relative positions of the charged calcium ligands is crucial for catalytic activity. The importance of the electrostatic potential at the active site was furthermore revealed by various mutations of residues lining the interior of the central water-filled tunnel, which traverses the entire protein structure. In this respect, the structural features of residue His181, which is located at the opposite end of the DFPase tunnel relative to the active site, were characterized extensively. It was concluded that a tunnel-spanning hydrogen bond network, which includes a large number of apparently slow exchanging water molecules, relays any modifications in the electrostatics of the system to the active site, thus affecting the catalytic reactivity of the enzyme.

Mutational and structural studies of the diisopropylfluorophosphatase from Loligo vulgaris shed new light on the catalytic mechanism of the enzyme.,Katsemi V, Lucke C, Koepke J, Lohr F, Maurer S, Fritzsch G, Ruterjans H Biochemistry. 2005 Jun 28;44(25):9022-33. PMID:15966726<ref>PMID:15966726</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2iax" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Loligo vulgaris]]
[[Category: Fritzsch G]]
[[Category: Katsemi V]]
[[Category: Koepke J]]
[[Category: Loehr F]]
[[Category: Luecke C]]
[[Category: Maurer S]]
[[Category: Rueterjans H]]