1en4: Difference between revisions

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[[Image:1en4.jpg|left|200px]]


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==CRYSTAL STRUCTURE ANALYSIS OF THE E. COLI MANGANESE SUPEROXIDE DISMUTASE Q146H MUTANT==
The line below this paragraph, containing "STRUCTURE_1en4", creates the "Structure Box" on the page.
<StructureSection load='1en4' size='340' side='right'caption='[[1en4]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
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== Structural highlights ==
or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
<table><tr><td colspan='2'>[[1en4]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EN4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EN4 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]] 2&#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=MN:MANGANESE+(II)+ION'>MN</scene></td></tr>
{{STRUCTURE_1en4| PDB=1en4 |  SCENE= }}
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1en4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1en4 OCA], [https://pdbe.org/1en4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1en4 RCSB], [https://www.ebi.ac.uk/pdbsum/1en4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1en4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SODM_ECOLI SODM_ECOLI] Destroys superoxide anion radicals which are normally produced within the cells and which are toxic to biological systems.
== 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/en/1en4_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=1en4 ConSurf].
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'''CRYSTAL STRUCTURE ANALYSIS OF THE E. COLI MANGANESE SUPEROXIDE DISMUTASE Q146H MUTANT'''
==See Also==
 
*[[Superoxide dismutase 3D structures|Superoxide dismutase 3D structures]]
 
__TOC__
==Overview==
</StructureSection>
Tyrosine 34 and glutamine 146 are highly conserved outer sphere residues in the mononuclear manganese active site of Escherichia coli manganese superoxide dismutase. Biochemical and spectroscopic characterization of site-directed mutants has allowed functional characterization of these residues in the wild-type (wt) enzyme. X-ray crystallographic analysis of three mutants (Y34F, Q146L, and Q146H) reveal subtle changes in the protein structures. The Y34A mutant, as well as the previously reported Y34F mutant, retained essentially the full superoxide dismutase activity of the wild-type enzyme, and the X-ray crystal structure of Y34F manganese superoxide dismutase shows that mutation of this strictly conserved residue has only minor effects on the positions of active site residues and the organized water in the substrate access funnel. Mutation of the outer sphere solvent pocket residue Q146 has more dramatic effects. The Q146E mutant is isolated as an apoprotein lacking dismutase activity. Q146L and Q146H mutants retain only 5-10% of the dismutase activity of the wild-type enzyme. The absorption and circular dichroism spectra of the Q146H mutant resemble corresponding data for the superoxide dismutase from a hyperthermophilic archaeon, Pyrobaculum aerophilum, which is active in both Mn and Fe forms. Interestingly, the iron-substituted Q146H protein also exhibits low dismutase activity, which increases at lower pH. Mutation of glutamine 146 disrupts the hydrogen-bonding network in the active site and has a greater effect on protein structure than does the Y34F mutant, with rearrangement of the tyrosine 34 and tryptophan 128 side chains.
 
==About this Structure==
1EN4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EN4 OCA].
 
==Reference==
Outer sphere mutations perturb metal reactivity in manganese superoxide dismutase., Edwards RA, Whittaker MM, Whittaker JW, Baker EN, Jameson GB, Biochemistry. 2001 Jan 9;40(1):15-27. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11141052 11141052]
[[Category: Escherichia coli]]
[[Category: Escherichia coli]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Superoxide dismutase]]
[[Category: Baker EN]]
[[Category: Baker, E N.]]
[[Category: Edwards RA]]
[[Category: Edwards, R A.]]
[[Category: Jameson GB]]
[[Category: Jameson, G B.]]
[[Category: Whittaker JW]]
[[Category: Whittaker, J W.]]
[[Category: Whittaker MM]]
[[Category: Whittaker, M M.]]
[[Category: Manganese superoxide dismutase]]
[[Category: Mutant]]
[[Category: Proton shuttle]]
[[Category: Q146h]]
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