1mep: Difference between revisions

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-[[Image:1mep.gif|left|200px]]<br /><applet load="1mep" size="350" color="white" frame="true" align="right" spinBox="true"
-caption="1mep, resolution 1.65&Aring;" />
-'''Crystal Structure of Streptavidin Double Mutant S45A/D128A with Biotin: Cooperative Hydrogen-Bond Interactions in the Streptavidin-Biotin System.'''<br />
-==Overview==
+==Crystal Structure of Streptavidin Double Mutant S45A/D128A with Biotin: Cooperative Hydrogen-Bond Interactions in the Streptavidin-Biotin System.==
-The thermodynamic and structural cooperativity between the Ser45- and D128-biotin hydrogen bonds was measured by calorimetric and X-ray crystallographic studies of the S45A/D128A double mutant of streptavidin. The double mutant exhibits a binding affinity approximately 2x10(7) times lower than that of wild-type streptavidin at 25 degrees C. The corresponding reduction in binding free energy (DeltaDeltaG) of 10.1 kcal/mol was nearly completely due to binding enthalpy losses at this temperature. The loss of binding affinity is 11-fold greater than that predicted by a linear combination of the single-mutant energetic perturbations (8.7 kcal/mol), indicating that these two mutations interact cooperatively. Crystallographic characterization of the double mutant and comparison with the two single mutant structures suggest that structural rearrangements at the S45 position, when the D128 carboxylate is removed, mask the true energetic contribution of the D128-biotin interaction. Taken together, the thermodynamic and structural analyses support the conclusion that the wild-type hydrogen bond between D128-OD and biotin-N2 is thermodynamically stronger than that between S45-OG and biotin-N1.
+<StructureSection load='1mep' size='340' side='right'caption='[[1mep]], [[Resolution|resolution]] 1.65&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[1mep]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_avidinii Streptomyces avidinii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MEP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1MEP 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]] 1.65&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BTN:BIOTIN'>BTN</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=1mep FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1mep OCA], [https://pdbe.org/1mep PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1mep RCSB], [https://www.ebi.ac.uk/pdbsum/1mep PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1mep ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/SAV_STRAV SAV_STRAV] The biological function of streptavidin is not known. Forms a strong non-covalent specific complex with biotin (one molecule of biotin per subunit of streptavidin).
+== 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/me/1mep_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=1mep ConSurf].
+<div style="clear:both"></div>
-==About this Structure==
+==See Also==
-MEP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_avidinii Streptomyces avidinii] with <scene name='pdbligand=BTN:'>BTN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MEP OCA].
+*[[Avidin 3D structures|Avidin 3D structures]]
+__TOC__
-==Reference==
+</StructureSection>
-Cooperative hydrogen bond interactions in the streptavidin-biotin system., Hyre DE, Le Trong I, Merritt EA, Eccleston JF, Green NM, Stenkamp RE, Stayton PS, Protein Sci. 2006 Mar;15(3):459-67. Epub 2006 Feb 1. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16452627 16452627]
+[[Category: Large Structures]]
-[[Category: Single protein]]
 [[Category: Streptomyces avidinii]]
-[[Category: Green, N M.]]
+[[Category: Green NM]]
-[[Category: Hyre, D E.]]
+[[Category: Hyre DE]]
-[[Category: Merritt, E A.]]
+[[Category: Le Trong I]]
-[[Category: Stayton, P S.]]
+[[Category: Merritt EA]]
-[[Category: Stenkamp, R E.]]
+[[Category: Stayton PS]]
-[[Category: Trong, I Le.]]
+[[Category: Stenkamp RE]]
-[[Category: BTN]]
-[[Category: biotin-binding protein]]
-[[Category: homotetramer]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:54:30 2008''