View source for 7aq8


==Pseudomonas stutzeri nitrous oxide reductase mutant, H583Y/D576A==
<StructureSection load='7aq8' size='340' side='right'caption='[[7aq8]], [[Resolution|resolution]] 1.79&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7AQ8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7AQ8 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]] 1.791&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=B3P:2-[3-(2-HYDROXY-1,1-DIHYDROXYMETHYL-ETHYLAMINO)-PROPYLAMINO]-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>B3P</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=CUA:DINUCLEAR+COPPER+ION'>CUA</scene>, <scene name='pdbligand=CUZ:(MU-4-SULFIDO)-TETRA-NUCLEAR+COPPER+ION'>CUZ</scene>, <scene name='pdbligand=FMT:FORMIC+ACID'>FMT</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=7aq8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7aq8 OCA], [https://pdbe.org/7aq8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7aq8 RCSB], [https://www.ebi.ac.uk/pdbsum/7aq8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7aq8 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Copper-containing nitrous oxide reductase (N2OR) is the only known enzyme to catalyze the conversion of the environmentally critical greenhouse gas nitrous oxide (N2O) to dinitrogen (N2) as the final step of bacterial denitrification. Other than its unique tetranuclear active site CuZ, the binuclear electron entry point CuA is also utilized in other enzymes, including cytochrome c oxidase. In the CuA site of Pseudomonas stutzeri N2OR, a histidine ligand was found to undergo a conformational flip upon binding of the substrate N2O between the two copper centers. Here we report on the systematic mutagenesis and spectroscopic and structural characterization of this histidine and surrounding H-bonding residues, based on an established functional expression system for PsN2OR in E. coli. A single hydrogen bond from Ser550 is sufficient to stabilize an unbound conformation of His583, as shown in a Asp576Ala variant, while the additional removal of the hydrogen bond in a Asp576Ala/Ser550Ala double variant compelled His583 to stay in a bound conformation as a ligand to CuA. Systematic mutagenesis of His583 to Ala, Asp, Asn, Glu, Gln, Lys, Phe, Tyr, and Trp showed that although both the CuZ and CuA sites were present in all the variants, only the ones with a protonable side chain, i.e., His, Asp, and Glu, were able to mediate electron transfer at physiological pH. This observation is in line with a proton-coupled electron transfer mechanism at the CuA site of N2OR.

Histidine-Gated Proton-Coupled Electron Transfer to the CuA Site of Nitrous Oxide Reductase.,Zhang L, Bill E, Kroneck PMH, Einsle O J Am Chem Soc. 2020 Dec 30. doi: 10.1021/jacs.0c10057. PMID:33377777<ref>PMID:33377777</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7aq8" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Bill E]]
[[Category: Einsle O]]
[[Category: Kroneck PMH]]
[[Category: Zhang L]]