View source for 1et5


==CRYSTAL STRUCTURE OF NITRITE REDUCTASE ASP98ASN MUTANT FROM ALCALIGENES FAECALIS S-6==
<StructureSection load='1et5' size='340' side='right'caption='[[1et5]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1et5]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Alcfa Alcfa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ET5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ET5 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1et7|1et7]], [[1et8|1et8]], [[2afn|2afn]], [[1as7|1as7]]</div></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Nitrite_reductase_(NO-forming) Nitrite reductase (NO-forming)], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.2.1 1.7.2.1] </span></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=1et5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1et5 OCA], [https://pdbe.org/1et5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1et5 RCSB], [https://www.ebi.ac.uk/pdbsum/1et5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1et5 ProSAT]</span></td></tr>
</table>
== 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/et/1et5_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=1et5 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Two active site residues, Asp-98 and His-255, of copper-containing nitrite reductase (NIR) from Alcaligenes faecalis have been mutated to probe the catalytic mechanism. Three mutations at these two sites (D98N, H255D, and H255N) result in large reductions in activity relative to native NIR, suggesting that both residues are involved intimately in the reaction mechanism. Crystal structures of these mutants have been determined using data collected to better than 1. 9-A resolution. In the native structure, His-255 Nepsilon2 forms a hydrogen bond through a bridging water molecule to the side chain of Asp-98, which also forms a hydrogen bond to a water or nitrite oxygen ligated to the active site copper. In the D98N mutant, reorientation of the Asn-98 side chain results in the loss of the hydrogen bond to the copper ligand water, consistent with a negatively charged Asp-98 directing the binding and protonation of nitrite in the native enzyme. An additional solvent molecule is situated between residues 255 and the bridging water in the H255N and H255D mutants and likely inhibits nitrite binding. The interaction of His-255 with the bridging water appears to be necessary for catalysis and may donate a proton to reaction intermediates in addition to Asp-98.

Catalytic roles for two water bridged residues (Asp-98 and His-255) in the active site of copper-containing nitrite reductase.,Boulanger MJ, Kukimoto M, Nishiyama M, Horinouchi S, Murphy ME J Biol Chem. 2000 Aug 4;275(31):23957-64. PMID:10811642<ref>PMID:10811642</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1et5" style="background-color:#fffaf0;"></div>

==See Also==
*[[Nitrite reductase 3D structures|Nitrite reductase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Alcfa]]
[[Category: Large Structures]]
[[Category: Boulanger, M J]]
[[Category: Horinouchi, S]]
[[Category: Kukimoto, M]]
[[Category: Murphy, M E.P]]
[[Category: Nishiyama, M]]
[[Category: Greek key beta barrel domain]]
[[Category: Oxidoreductase]]