8paz

<StructureSection load='8paz' size='340' side='right' caption='[[8paz]], [[Resolution|resolution]] 1.60&Aring;' scene=''>

<table><tr><td colspan='2'>[[8paz]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Alcfa Alcfa]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=2paz 2paz]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8PAZ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=8PAZ FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3paz|3paz]], [[4paz|4paz]], [[5paz|5paz]], [[6paz|6paz]], [[7paz|7paz]]</td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">POTENTIAL ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=511 ALCFA])</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=8paz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8paz OCA], [http://pdbe.org/8paz PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=8paz RCSB], [http://www.ebi.ac.uk/pdbsum/8paz PDBsum]</span></td></tr>

[[http://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.

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pa/8paz_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

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.

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:9341204<ref>PMID:9341204</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 8paz" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Alcfa]]

[[Category: Adman, E T]]

[[Category: Libeu, C A.P]]

[[Category: Cuproprotein]]

[[Category: Electron transfer]]