View source for 6t31


==Streptavidin variants harbouring an artificial organocatalyst based cofactor==
<StructureSection load='6t31' size='340' side='right'caption='[[6t31]], [[Resolution|resolution]] 1.35&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6t31]] 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=6T31 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6T31 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]] 1.35&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HL9:5-[(3~{a}~{S},4~{S},6~{a}~{R})-2-oxidanylidene-1,3,3~{a},4,6,6~{a}-hexahydrothieno[3,4-d]imidazol-4-yl]-~{N}-(1-pyridin-4-ylpiperidin-4-yl)pentanamide'>HL9</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=6t31 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6t31 OCA], [https://pdbe.org/6t31 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6t31 RCSB], [https://www.ebi.ac.uk/pdbsum/6t31 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6t31 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).
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
An artificial cofactor based on an organocatalyst embedded in a protein has been used to conduct the Baylis-Hillman reaction in a buffered system. As protein host, we chose streptavidin, as it can be easily crystallized and thereby supports the design process. The protein host around the cofactor was rationally designed on the basis of high-resolution crystal structures obtained after each variation of the amino acid sequence. Additionally, DFT-calculated intermediates and transition states were used to rationalize the observed activity. Finally, repeated cycles of structure determination and redesign led to a system with an up to one order of magnitude increase in activity over the bare cofactor and to the most active proteinogenic catalyst for the Baylis-Hillman reaction known today.

An Artificial Cofactor Catalyzing the Baylis-Hillman Reaction with Designed Streptavidin as Protein Host*.,Lechner H, Emann VR, Breuning M, Hocker B Chembiochem. 2021 Jan 5. doi: 10.1002/cbic.202000880. PMID:33400831<ref>PMID:33400831</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6t31" style="background-color:#fffaf0;"></div>

==See Also==
*[[Avidin 3D structures|Avidin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces avidinii]]
[[Category: Hocker B]]
[[Category: Lechner H]]