View source for 5uxz


==X-ray crystal structure of Halotag bound to the P9 benzothiadiazole fluorogenic ligand==
<StructureSection load='5uxz' size='340' side='right'caption='[[5uxz]], [[Resolution|resolution]] 1.92&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5uxz]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Rhodococcus_rhodochrous Rhodococcus rhodochrous]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5UXZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5UXZ 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]] 1.92&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=8PM:N~2~-{[7-(DIMETHYLAMINO)-2,1,3-BENZOTHIADIAZOL-4-YL]SULFONYL}-N-HEXYL-N~2~-METHYLGLYCINAMIDE'>8PM</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</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=5uxz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5uxz OCA], [https://pdbe.org/5uxz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5uxz RCSB], [https://www.ebi.ac.uk/pdbsum/5uxz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5uxz ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DHAA_RHORH DHAA_RHORH] Catalyzes hydrolytic cleavage of carbon-halogen bonds in halogenated aliphatic compounds, leading to the formation of the corresponding primary alcohols, halide ions and protons. Expresses halogenase activity against 1-chloroalkanes of chain length C3 to C10, and also shows a very weak activity with 1,2-dichloroethane.
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== Publication Abstract from PubMed ==
Design of fluorogenic probes for Halo-tag is highly desirable but challenging. Previous work achieved this goal by controlling the chemical switch of spirolactones upon the covalent conju-gation between Halo-tag and probes or by incorporating a 'channel dye' into the substrate bind-ing tunnel of Halo-tag. In this work, we have developed a novel class of Halo-tag fluorogenic probes that are derived from solvatochromic fluorophores. The optimal probe, harboring a ben-zothiadiazole scaffold, exhibits a 1000-fold fluorescence enhancement upon reaction with Halo-tag. Structural, computational and biochemical studies reveal that the benzene ring of a trypto-phan residue engages in a cation-pi interaction with the dimethylamino electron-donating group of the benzothiadiazole fluorophore in its excited state. We further demonstrate using non-canonical fluorinated tryptophan that the cation-pi interaction directly contributes to fluorogenici-ty of the benzothiadiazole fluorophore. Mechanistically, this interaction could contribute to the fluorogenicity by promoting the excited-state charge separation and inhibiting the twisting mo-tion of the dimethyl-amino group, both leading to an enhanced fluorogenicity. Finally, we demonstrate the utility of the probe in no-wash direct imaging of Halo-tagged proteins in live cells. In addition, the fluorogenic nature of the probe enables a gel-free quantification of fusion proteins expressed in mammalian cells, an application that was not possible with previously non-fluorogenic Halo-tag probes. The unique mechanism revealed by this work suggests that incor-poration of an excited-state cation-pi interaction could be a feasible strategy to enhance optical performance of fluorophores and fluorogenic sensors.

The Cation-pi Interaction Enables a Halo-Tag Fluorogenic Probe for Fast No-Wash Live Cell Imaging and Gel-Free Protein Quantification.,Liu Y, Miao K, Dunham NP, Liu H, Fares M, Boal AK, Li X, Zhang X Biochemistry. 2017 Feb 21. doi: 10.1021/acs.biochem.7b00056. PMID:28221782<ref>PMID:28221782</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 5uxz" style="background-color:#fffaf0;"></div>

==See Also==
*[[Dehalogenase 3D structures|Dehalogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rhodococcus rhodochrous]]
[[Category: Boal AK]]
[[Category: Dunham NP]]