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4paz

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[[Image:4paz.jpg|left|200px]]<br /><applet load="4paz" size="350" color="white" frame="true" align="right" spinBox="true"
 
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caption="4paz, resolution 1.76&Aring;" />
 
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'''OXIDIZED MUTANT P80A PSEUDOAZURIN FROM A. FAECALIS'''<br />
 
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==Overview==
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==OXIDIZED MUTANT P80A PSEUDOAZURIN FROM A. FAECALIS==
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In order to understand the origins of differences in redox potentials among cupredoxins (small blue type I copper-containing proteins that reversibly change oxidation state and interact with redox partners), we have determined the structures of the native and two mutants (P80A and P80I) of pseudoazurin from Alcaligenes faecalis S-6 in oxidized and reduced forms at resolutions of 2.2 A in the worst case and 1.6 A in the best case. The P80A mutation creates a surface pocket filled by a new water molecule, whereas the P80I mutant excludes this water. Distinct patterns of change occur in response to reduction for all three molecules: the copper position shifts, Met 7 and Pro 35 move, and the relative orientations of residues 81 to 16, 18 to the amide planes of 77 and 86, all change. Systematic changes in the weak electrostatic interactions seen in the structures of different oxidation states can explain the Met 7/Pro 35 structural differences as well as some fluctuating solvent positions. Overall displacement parameters increase reversibly upon reduction. The reduced forms are slightly expanded over the oxidized forms. The geometries of the mutants become more trigonal in their reduced forms, consistent with higher redox potentials (+409 mV for P80A and +450 mV for P80I). Calculations of the differences in redox potentials, using POLARIS, reveal that a water unique to the P80A mutant is required (with correctly oriented hydrogens) to approximate the observed difference in redox potential. The POLARIS calculations suggest that the reduced forms are additionally stabilized through changes in the solvation of the copper center, specifically via the amides of residues 16, 39, 41, 79, and 80 which interact with either Phe 18, Met 86, or Cys 78. The redox potential of P80A is increased largely due to solvation effects, whereas the redox potential of P80I is increased largely due to geometrical effects.
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<StructureSection load='4paz' size='340' side='right'caption='[[4paz]], [[Resolution|resolution]] 1.76&Aring;' scene=''>
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== Structural highlights ==
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<table><tr><td colspan='2'>[[4paz]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Alcaligenes_faecalis Alcaligenes faecalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4PAZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4PAZ FirstGlance]. <br>
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.76&#8491;</td></tr>
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<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></td></tr>
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4paz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4paz OCA], [https://pdbe.org/4paz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4paz RCSB], [https://www.ebi.ac.uk/pdbsum/4paz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4paz ProSAT]</span></td></tr>
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</table>
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== Function ==
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[https://www.uniprot.org/uniprot/AZUP_ALCFA AZUP_ALCFA] This soluble electron transfer copper protein is required for the inactivation of copper-containing nitrite reductase in the presence of oxygen. Serves as a direct electron donor to the nitrite reductase.
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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pa/4paz_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</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=4paz ConSurf].
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<div style="clear:both"></div>
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==About this Structure==
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==See Also==
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4PAZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Alcaligenes_faecalis Alcaligenes faecalis] with <scene name='pdbligand=CU:'>CU</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Known structural/functional Site: <scene name='pdbsite=CU:Active+Site+For+Electron+transf.'>CU</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4PAZ OCA].
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*[[Pseudoazurin|Pseudoazurin]]
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__TOC__
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==Reference==
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</StructureSection>
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Site-directed mutants of pseudoazurin: explanation of increased redox potentials from X-ray structures and from calculation of redox potential differences., Libeu CA, Kukimoto M, Nishiyama M, Horinouchi S, Adman ET, Biochemistry. 1997 Oct 28;36(43):13160-79. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9341204 9341204]
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[[Category: Alcaligenes faecalis]]
[[Category: Alcaligenes faecalis]]
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[[Category: Single protein]]
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[[Category: Large Structures]]
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[[Category: Adman, E T.]]
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[[Category: Adman ET]]
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[[Category: Libeu, C A.P.]]
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[[Category: Libeu CAP]]
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[[Category: CU]]
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[[Category: cuproprotein]]
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[[Category: electron transfer]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:14:00 2008''
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Current revision

OXIDIZED MUTANT P80A PSEUDOAZURIN FROM A. FAECALIS

PDB ID 4paz

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