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| | <StructureSection load='6qsy' size='340' side='right'caption='[[6qsy]], [[Resolution|resolution]] 1.70Å' scene=''> | | <StructureSection load='6qsy' size='340' side='right'caption='[[6qsy]], [[Resolution|resolution]] 1.70Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6qsy]] is a 2 chain structure with sequence from [https://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=6QSY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6QSY FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6qsy]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_avidinii Streptomyces avidinii] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6QSY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6QSY FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PGE:TRIETHYLENE+GLYCOL'>PGE</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</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]] 1.7Å</td></tr> |
| - | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=BE2:2-AMINOBENZOIC+ACID'>BE2</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BE2:2-AMINOBENZOIC+ACID'>BE2</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene>, <scene name='pdbligand=PGE:TRIETHYLENE+GLYCOL'>PGE</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[6qbb|6qbb]], [[1rst|1rst]]</div></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=6qsy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qsy OCA], [https://pdbe.org/6qsy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6qsy RCSB], [https://www.ebi.ac.uk/pdbsum/6qsy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6qsy ProSAT]</span></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=6qsy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qsy OCA], [https://pdbe.org/6qsy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6qsy RCSB], [https://www.ebi.ac.uk/pdbsum/6qsy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6qsy ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == 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).
| + | [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). |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: As 4 1583]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Eichinger, A]] | + | [[Category: Streptomyces avidinii]] |
| - | [[Category: Skerra, A]] | + | [[Category: Synthetic construct]] |
| - | [[Category: Loop engineering]] | + | [[Category: Eichinger A]] |
| - | [[Category: Peptide binding protein]] | + | [[Category: Skerra A]] |
| - | [[Category: Protein engineering]]
| + | |
| - | [[Category: Strep-tag]]
| + | |
| - | [[Category: Streptavidin]]
| + | |
| 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).
Publication Abstract from PubMed
The affinity system based on the artificial peptide ligand Strep-tag(R) II and engineered tetrameric streptavidin, known as Strep-Tactin(R), offers attractive applications for the study of recombinant proteins, from detection and purification to functional immobilization. To further improve binding of the Strep-tag II to streptavidin we have subjected two protruding loops that shape its ligand pocket for the peptide - instead of D-biotin recognized by the natural protein - to iterative random mutagenesis. Sequence analyses of hits from functional screening assays revealed several unexpected structural motifs, such as a disulfide bridge at the base of one loop, replacement of the crucial residue Trp120 by Gly and a two-residue deletion in the second loop. The mutant m1-9 (dubbed Strep-Tactin XT) showed strongly enhanced affinity towards the Strep-tag II, which was further boosted in case of the bivalent Twin-Strep-tag(R). Four representative streptavidin mutants were crystallized in complex with the Strep-tag II peptide and their X-ray structures were solved at high resolutions. In addition, the crystal structure of the complex between Strep-Tactin XT and the Twin-Strep-tag was elucidated, indicating a bivalent mode of binding and explaining the experimentally observed avidity effect. Our study illustrates the structural plasticity of streptavidin as a scaffold for ligand binding and reveals interaction modes that would have been difficult to predict. As result, Strep-Tactin XT offers a convenient reagent for the kinetically stable immobilization of recombinant proteins fused with the Twin-Strep-tag. The possibility of reversibly dissociating such complexes simply with D-biotin as a competing ligand enables functional studies in protein science as well as cell biology.
The Role of Changing Loop Conformations in Streptavidin Versions Engineered for High-affinity Binding of the Strep-tag II Peptide.,Schmidt TGM, Eichinger A, Schneider M, Bonet L, Carl U, Karthaus D, Theobald I, Skerra A J Mol Biol. 2021 Apr 30;433(9):166893. doi: 10.1016/j.jmb.2021.166893. Epub 2021 , Feb 24. PMID:33639211[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Schmidt TGM, Eichinger A, Schneider M, Bonet L, Carl U, Karthaus D, Theobald I, Skerra A. The Role of Changing Loop Conformations in Streptavidin Versions Engineered for High-affinity Binding of the Strep-tag II Peptide. J Mol Biol. 2021 Apr 30;433(9):166893. doi: 10.1016/j.jmb.2021.166893. Epub 2021 , Feb 24. PMID:33639211 doi:http://dx.doi.org/10.1016/j.jmb.2021.166893
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