View source for 4ax3


==Structure of three-domain heme-Cu nitrite reductase from Ralstonia pickettii at 1.6 A resolution==
<StructureSection load='4ax3' size='340' side='right'caption='[[4ax3]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4ax3]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Ralstonia_pickettii_12J Ralstonia pickettii 12J]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AX3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4AX3 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]] 1.6&#8491;</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=HEC:HEME+C'>HEC</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=4ax3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ax3 OCA], [https://pdbe.org/4ax3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ax3 RCSB], [https://www.ebi.ac.uk/pdbsum/4ax3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ax3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/B2UHR8_RALPJ B2UHR8_RALPJ] 
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== Publication Abstract from PubMed ==
Electron transfer reactions are essential for life because they underpin oxidative phosphorylation and photosynthesis, processes leading to the generation of ATP, and are involved in many reactions of intermediary metabolism. Key to these roles is the formation of transient inter-protein electron transfer complexes. The structural basis for the control of specificity between partner proteins is lacking because these weak transient complexes have remained largely intractable for crystallographic studies. Inter-protein electron transfer processes are central to all of the key steps of denitrification, an alternative form of respiration in which bacteria reduce nitrate or nitrite to N2 through the gaseous intermediates nitric oxide (NO) and nitrous oxide (N2O) when oxygen concentrations are limiting. The one-electron reduction of nitrite to NO, a precursor to N2O, is performed by either a haem- or copper-containing nitrite reductase (CuNiR) where they receive an electron from redox partner proteins a cupredoxin or a c-type cytochrome. Here we report the structures of the newly characterized three-domain haem-c-Cu nitrite reductase from Ralstonia pickettii (RpNiR) at 1.01 A resolution and its M92A and P93A mutants. Very high resolution provides the first view of the atomic detail of the interface between the core trimeric cupredoxin structure of CuNiR and the tethered cytochrome c domain that allows the enzyme to function as an effective self-electron transfer system where the donor and acceptor proteins are fused together by genomic acquisition for functional advantage. Comparison of RpNiR with the binary complex of a CuNiR with a donor protein, AxNiR-cytc551 (ref. 6), and mutagenesis studies provide direct evidence for the importance of a hydrogen-bonded water at the interface in electron transfer. The structure also provides an explanation for the preferential binding of nitrite to the reduced copper ion at the active site in RpNiR, in contrast to other CuNiRs where reductive inactivation occurs, preventing substrate binding.

Structures of protein-protein complexes involved in electron transfer.,Antonyuk SV, Han C, Eady RR, Hasnain SS Nature. 2013 Apr 4;496(7443):123-6. doi: 10.1038/nature11996. Epub 2013 Mar 27. PMID:23535590<ref>PMID:23535590</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 4ax3" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome c nitrite reductase|Cytochrome c nitrite reductase]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Ralstonia pickettii 12J]]
[[Category: Antonyuk SV]]
[[Category: Cong H]]
[[Category: Eady RR]]
[[Category: Hasnain SS]]