View source for 8fxu


==Thermoanaerobacter thermosaccharolyticum periplasmic Glucose-Binding Protein glucose complex: Badan conjugate attached at F17C==
<StructureSection load='8fxu' size='340' side='right'caption='[[8fxu]], [[Resolution|resolution]] 1.59&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8fxu]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermoanaerobacterium_thermosaccharolyticum Thermoanaerobacterium thermosaccharolyticum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8FXU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8FXU 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]] 1.59&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=YDQ:2-bromo-1-[6-(dimethylamino)naphthalen-2-yl]ethan-1-one'>YDQ</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=8fxu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8fxu OCA], [https://pdbe.org/8fxu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8fxu RCSB], [https://www.ebi.ac.uk/pdbsum/8fxu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8fxu ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Fluorescent labeling of proteins is a powerful tool for probing structure-function relationships with many biosensing applications. Structure-based rules for systematically designing fluorescent biosensors require understanding ligand-mediated fluorescent response mechanisms which can be challenging to establish. We installed thiol-reactive derivatives of the naphthalene-based fluorophore Prodan into bacterial periplasmic glucose-binding proteins. Glucose binding elicited paired color exchanges in the excited and ground states of these conjugates. X-ray structures and mutagenesis studies established that glucose-mediated color switching arises from steric interactions that couple protein conformational changes to twisting of the Prodan carbonyl relative to its naphthalene plane. Mutations of residues contacting the carbonyl can optimize color switching by altering fluorophore conformational equilibria in the apo and glucose-bound proteins. A commonly accepted view is that Prodan derivatives report on protein conformations via solvatochromic effects due to changes in the dielectric of their local environment. Here we show that instead Prodan carbonyl twisting controls color switching. These insights enable structure-based biosensor design by coupling ligand-mediated protein conformational changes to internal chromophore twists through specific steric interactions between fluorophore and protein.

Chromophore carbonyl twisting in fluorescent biosensors encodes direct readout of protein conformations with multicolor switching.,Allert MJ, Kumar S, Wang Y, Beese LS, Hellinga HW Commun Chem. 2023 Aug 19;6(1):168. doi: 10.1038/s42004-023-00982-7. PMID:37598249<ref>PMID:37598249</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8fxu" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermoanaerobacterium thermosaccharolyticum]]
[[Category: Allert MJ]]
[[Category: Beese LS]]
[[Category: Hellinga HW]]
[[Category: Kumar S]]