View source for 2qka


==Structural and Kinetic Study of the Differences between Human and E.coli Manganese Superoxide Dismutases==
<StructureSection load='2qka' size='340' side='right'caption='[[2qka]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2qka]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QKA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QKA 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</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=2qka FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qka OCA], [https://pdbe.org/2qka PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qka RCSB], [https://www.ebi.ac.uk/pdbsum/2qka PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qka ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/SODM_HUMAN SODM_HUMAN] Genetic variation in SOD2 is associated with susceptibility to microvascular complications of diabetes type 6 (MVCD6) [MIM:[https://omim.org/entry/612634 612634]. These are pathological conditions that develop in numerous tissues and organs as a consequence of diabetes mellitus. They include diabetic retinopathy, diabetic nephropathy leading to end-stage renal disease, and diabetic neuropathy. Diabetic retinopathy remains the major cause of new-onset blindness among diabetic adults. It is characterized by vascular permeability and increased tissue ischemia and angiogenesis.
== Function ==
[https://www.uniprot.org/uniprot/SODM_HUMAN SODM_HUMAN] Destroys superoxide anion radicals which are normally produced within the cells and which are toxic to biological systems.<ref>PMID:10334867</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/qk/2qka_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</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=2qka ConSurf].
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== Publication Abstract from PubMed ==
Human manganese superoxide dismutase (MnSOD) is characterized by a product inhibition stronger than that observed in bacterial forms of MnSOD. Previous studies show that the conserved, active-site residue Tyr34 mediates product inhibition; however, the protein environment of Tyr34 is different in human and Escherichia coli MnSOD. We have prepared two site-specific mutants of human MnSOD with replacements of Phe66 with Ala and Leu (F66A and F66L, respectively), altering the surroundings of Tyr34. Pulse radiolysis was used to generate superoxide, and measurements of catalysis were taken in single-turnover experiments by observing the visible absorbance of species of MnSOD and under catalytic conditions observing the absorbance of superoxide. The mutation of Phe66 to Leu resulted in a mutant of human MnSOD with weakened product inhibition resembling that of E. coli MnSOD. Moreover, the mechanism of this weakened product inhibition was similar to that in E. coli MnSOD, specifically a decrease in the rate constant for the oxidative addition of superoxide to Mn2+MnSOD leading to the formation of the peroxide-inhibited enzyme. In addition, the crystal structures of both mutants have been determined and compared to those of wild-type human and E. coli MnSOD. The crystallographic data suggest that the solvent structure and its mobility as well as side chain conformations may affect the extent of product inhibition. These data emphasize the role of residue 66 in catalysis and inhibition and provide a structural explanation for differences in catalytic properties between human and certain bacterial forms of MnSOD.

Structural and kinetic study of differences between human and Escherichia coli manganese superoxide dismutases.,Zheng J, Domsic JF, Cabelli D, McKenna R, Silverman DN Biochemistry. 2007 Dec 25;46(51):14830-7. Epub 2007 Nov 29. PMID:18044968<ref>PMID:18044968</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Superoxide dismutase 3D structures|Superoxide dismutase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Cabelli D]]
[[Category: Domsic JF]]
[[Category: McKenna R]]
[[Category: Silverman DN]]
[[Category: Zheng J]]