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| | ==S45A MUTANT OF STREPTAVIDIN IN COMPLEX WITH BIOTIN== | | ==S45A MUTANT OF STREPTAVIDIN IN COMPLEX WITH BIOTIN== |
| - | <StructureSection load='1df8' size='340' side='right' caption='[[1df8]], [[Resolution|resolution]] 1.51Å' scene=''> | + | <StructureSection load='1df8' size='340' side='right'caption='[[1df8]], [[Resolution|resolution]] 1.51Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1df8]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/As_4.1583 As 4.1583]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DF8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1DF8 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1df8]] is a 2 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=1DF8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1DF8 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BTN:BIOTIN'>BTN</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.51Å</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=1df8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1df8 OCA], [http://pdbe.org/1df8 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1df8 RCSB], [http://www.ebi.ac.uk/pdbsum/1df8 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1df8 ProSAT]</span></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=1df8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1df8 OCA], [https://pdbe.org/1df8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1df8 RCSB], [https://www.ebi.ac.uk/pdbsum/1df8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1df8 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://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). | + | [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 == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | </div> | | </div> |
| | <div class="pdbe-citations 1df8" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 1df8" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Avidin 3D structures|Avidin 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: As 4 1583]] | + | [[Category: Large Structures]] |
| - | [[Category: Freitag, S]] | + | [[Category: Streptomyces avidinii]] |
| - | [[Category: Hyre, D E]] | + | [[Category: Freitag S]] |
| - | [[Category: Stayton, P S]]
| + | [[Category: Hyre DE]] |
| - | [[Category: Stenkamp, R E]] | + | [[Category: Le Trong I]] |
| - | [[Category: Trong, I Le]] | + | [[Category: Stayton PS]] |
| - | [[Category: Binding protein]] | + | [[Category: Stenkamp RE]] |
| - | [[Category: Biotin]] | + | |
| - | [[Category: Biotin binding protein]]
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| Structural highlights
Function
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
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The contribution of the Ser45 hydrogen bond to biotin binding activation and equilibrium thermodynamics was investigated by biophysical and X-ray crystallographic studies. The S45A mutant exhibits a 1,700-fold greater dissociation rate and 907-fold lower equilibrium affinity for biotin relative to wild-type streptavidin at 37 degrees C, indicating a crucial role in binding energetics. The crystal structure of the biotin-bound mutant reveals only small changes from the wild-type bound structure, and the remaining hydrogen bonds to biotin retain approximately the same lengths. No additional water molecules are observed to replace the missing hydroxyl, in contrast to the previously studied D128A mutant. The equilibrium deltaG degrees, deltaH degrees, deltaS degrees, deltaC degrees(p), and activation deltaG++ of S45A at 37 degrees C are 13.7+/-0.1 kcal/mol, -21.1+/-0.5 kcal/mol, -23.7+/-1.8 cal/mol K, -223+/-12 cal/mol K, and 20.0+/-2.5 kcal/mol, respectively. Eyring analysis of the large temperature dependence of the S45A off-rate resolves the deltaH++ and deltaS++ of dissociation, 25.8+/-1.2 kcal/mol and 18.7+/-4.3 cal/mol K. The large increases of deltaH++ and deltaS++ in the mutant, relative to wild-type, indicate that Ser45 could form a hydrogen bond with biotin in the wild-type dissociation transition state, enthalpically stabilizing it, and constraining the transition state entropically. The postulated existence of a Ser45-mediated hydrogen bond in the wild-type streptavidin transition state is consistent with potential of mean force simulations of the dissociation pathway and with molecular dynamics simulations of biotin pullout, where Ser45 is seen to form a hydrogen bond with the ureido oxygen as biotin slips past this residue after breaking the native hydrogen bonds.
Ser45 plays an important role in managing both the equilibrium and transition state energetics of the streptavidin-biotin system.,Hyre DE, Le Trong I, Freitag S, Stenkamp RE, Stayton PS Protein Sci. 2000 May;9(5):878-85. PMID:10850797[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Hyre DE, Le Trong I, Freitag S, Stenkamp RE, Stayton PS. Ser45 plays an important role in managing both the equilibrium and transition state energetics of the streptavidin-biotin system. Protein Sci. 2000 May;9(5):878-85. PMID:10850797
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