1gn6: Difference between revisions

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-[[Image:1gn6.gif|left|200px]]<br />
-<applet load="1gn6" size="450" color="white" frame="true" align="right" spinBox="true"
-caption="1gn6, resolution 2.9&Aring;" />
-'''G152A MUTANT OF MYCOBACTERIUM TUBERCULOSIS IRON-SUPEROXIDE DISMUTASE.'''<br />
-==Overview==
+==G152A mutant of Mycobacterium tuberculosis iron-superoxide dismutase.==
-We have refined the X-ray structure of a site-directed G152A mutant of the, iron-dependent superoxide dismutase from Mycobacterium tuberculosis at 2.9, angstroms resolution. The mutation which replaces a glycine residue in a, surface loop with alanine was designed to alter the conformation of this, loop region which has previously been shown to play a crucial structural, role in quaternary interactions within the SOD tetramer. Gly-152 was, targeted as it has dihedral angles (phi = 83.1 degrees, psi = -0.3, degrees) close to the left-handed alpha-helical conformation which is, rarely adopted by other amino acids except asparagine. Gly-152 was, replaced by alanine as it has similar size and polarity, yet has a very, low tendency to adopt similar conformations. X-ray data collection on, crystals of this mutant at 2.9 angstroms resolution and subsequent, least-squares refinement to an R-value of 0.169 clearly establish that the, loop conformation is unaffected. Fluorescence studies of guanidine, hydrochloride denaturation establish that the mutant is 4 kcal/mol less, stable than the wild-type enzyme. Our results indicate that strict, conformational constraints imposed upon a region of polypeptide, due for, example to interactions with a neighbouring subunit, may force an alanine, residue to adopt this sterically hindered conformation with a consequent, reduction in stability of the folded conformation.
+<StructureSection load='1gn6' size='340' side='right'caption='[[1gn6]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[1gn6]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GN6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1GN6 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]] 2.9&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FE:FE+(III)+ION'>FE</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=1gn6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1gn6 OCA], [https://pdbe.org/1gn6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1gn6 RCSB], [https://www.ebi.ac.uk/pdbsum/1gn6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1gn6 ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/SODF_MYCTU SODF_MYCTU] 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/gn/1gn6_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=1gn6 ConSurf].
+<div style="clear:both"></div>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+We have refined the X-ray structure of a site-directed G152A mutant of the iron-dependent superoxide dismutase from Mycobacterium tuberculosis at 2.9 angstroms resolution. The mutation which replaces a glycine residue in a surface loop with alanine was designed to alter the conformation of this loop region which has previously been shown to play a crucial structural role in quaternary interactions within the SOD tetramer. Gly-152 was targeted as it has dihedral angles (phi = 83.1 degrees, psi = -0.3 degrees) close to the left-handed alpha-helical conformation which is rarely adopted by other amino acids except asparagine. Gly-152 was replaced by alanine as it has similar size and polarity, yet has a very low tendency to adopt similar conformations. X-ray data collection on crystals of this mutant at 2.9 angstroms resolution and subsequent least-squares refinement to an R-value of 0.169 clearly establish that the loop conformation is unaffected. Fluorescence studies of guanidine hydrochloride denaturation establish that the mutant is 4 kcal/mol less stable than the wild-type enzyme. Our results indicate that strict conformational constraints imposed upon a region of polypeptide, due for example to interactions with a neighbouring subunit, may force an alanine residue to adopt this sterically hindered conformation with a consequent reduction in stability of the folded conformation.
-==About this Structure==
+X-ray structure analysis of an engineered Fe-superoxide dismutase Gly-Ala mutant with significantly reduced stability to denaturant.,Cooper JB, Saward S, Erskine PT, Badasso MO, Wood SP, Zhang Y, Young D FEBS Lett. 1996 Jun 3;387(2-3):105-8. PMID:8674528<ref>PMID:8674528</ref>
-GN6 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis] with FE as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Superoxide_dismutase Superoxide dismutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.15.1.1 1.15.1.1] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1GN6 OCA].
-==Reference==
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
-X-ray structure analysis of an engineered Fe-superoxide dismutase Gly-Ala mutant with significantly reduced stability to denaturant., Cooper JB, Saward S, Erskine PT, Badasso MO, Wood SP, Zhang Y, Young D, FEBS Lett. 1996 Jun 3;387(2-3):105-8. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8674528 8674528]
+</div>
+<div class="pdbe-citations 1gn6" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[Superoxide dismutase 3D structures|Superoxide dismutase 3D structures]]
+== References ==
+<references/>
+__TOC__
+</StructureSection>
+[[Category: Large Structures]]
 [[Category: Mycobacterium tuberculosis]]
-[[Category: Single protein]]
+[[Category: Badasso MO]]
-[[Category: Superoxide dismutase]]
+[[Category: Bunting KA]]
-[[Category: Badasso, M.O.]]
+[[Category: Cooper JB]]
-[[Category: Bunting, K.A.]]
+[[Category: Erskine PT]]
-[[Category: Cooper, J.B.]]
+[[Category: Saward S]]
-[[Category: Erskine, P.T.]]
+[[Category: Wood SP]]
-[[Category: Saward, S.]]
+[[Category: Young DB]]
-[[Category: Wood, S.P.]]
+[[Category: Zhang Y]]
-[[Category: Young, D.B.]]
-[[Category: Zhang, Y.]]
-[[Category: FE]]
-[[Category: oxidoreductase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov  5 14:40:43 2007''