View source for 3sbq


==Pseudomonas stutzeri nitrous oxide reductase, P65 crystal form==
<StructureSection load='3sbq' size='340' side='right'caption='[[3sbq]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3sbq]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_stutzeri Pseudomonas stutzeri]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3SBQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3SBQ 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]] 1.7&#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>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=CUA:DINUCLEAR+COPPER+ION'>CUA</scene>, <scene name='pdbligand=CUK:[4CU 2S]+CLUSTER'>CUK</scene>, <scene name='pdbligand=IMD:IMIDAZOLE'>IMD</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</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=3sbq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3sbq OCA], [https://pdbe.org/3sbq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3sbq RCSB], [https://www.ebi.ac.uk/pdbsum/3sbq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3sbq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NOSZ_STUST NOSZ_STUST] Nitrous-oxide reductase is part of a bacterial respiratory system which is activated under anaerobic conditions in the presence of nitrate or nitrous oxide.<ref>PMID:3000778</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Nitrous oxide (N(2)O) is generated by natural and anthropogenic processes and has a critical role in environmental chemistry. It has an ozone-depleting potential similar to that of hydrochlorofluorocarbons as well as a global warming potential exceeding that of CO(2) 300-fold. In bacterial denitrification, N(2)O is reduced to N(2) by the copper-dependent nitrous oxide reductase (N(2)OR). This enzyme carries the mixed-valent Cu(A) centre and the unique, tetranuclear Cu(Z) site. Previous structural data were obtained with enzyme isolated in the presence of air that is catalytically inactive without prior reduction. Its Cu(Z) site was described as a [4Cu:S] centre, and the substrate-binding mode and reduction mechanism remained elusive. Here we report the structure of purple N(2)OR from Pseudomonas stutzeri, handled under the exclusion of dioxygen, and locate the substrate in N(2)O-pressurized crystals. The active Cu(Z) cluster contains two sulphur atoms, yielding a [4Cu:2S] stoichiometry; and N(2)O bound side-on at Cu(Z), in close proximity to Cu(A). With the substrate located between the two clusters, electrons are transferred directly from Cu(A) to N(2)O, which is activated by side-on binding in a specific binding pocket on the face of the [4Cu:2S] centre. These results reconcile a multitude of available biochemical data on N(2)OR that could not be explained by earlier structures, and outline a mechanistic pathway in which both metal centres and the intervening protein act in concert to achieve catalysis. This structure represents the first direct observation, to our knowledge, of N(2)O bound to its reductase, and sheds light on the functionality of metalloenzymes that activate inert small-molecule substrates. The principle of using distinct clusters for substrate activation and for reduction may be relevant for similar systems, in particular nitrogen-fixing nitrogenase.

N(2)O binding at a [4Cu:2S] copper-sulphur cluster in nitrous oxide reductase.,Pomowski A, Zumft WG, Kroneck PM, Einsle O Nature. 2011 Aug 14. doi: 10.1038/nature10332. PMID:21841804<ref>PMID:21841804</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3sbq" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas stutzeri]]
[[Category: Einsle O]]
[[Category: Kroneck PMH]]
[[Category: Pomowski A]]
[[Category: Zumft WG]]