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| | ==X-ray crystal structure of apo Halotag== | | ==X-ray crystal structure of apo Halotag== |
| - | <StructureSection load='5uy1' size='340' side='right' caption='[[5uy1]], [[Resolution|resolution]] 1.35Å' scene=''> | + | <StructureSection load='5uy1' size='340' side='right'caption='[[5uy1]], [[Resolution|resolution]] 1.35Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5uy1]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacterium_mycoides_roseum"_grotenfelt_1889 "bacterium mycoides roseum" grotenfelt 1889]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5UY1 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5UY1 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5uy1]] 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=5UY1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5UY1 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</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]] 1.35Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5uxz|5uxz]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">dhaA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1829 "Bacterium mycoides roseum" Grotenfelt 1889])</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=5uy1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5uy1 OCA], [https://pdbe.org/5uy1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5uy1 RCSB], [https://www.ebi.ac.uk/pdbsum/5uy1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5uy1 ProSAT]</span></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Haloalkane_dehalogenase Haloalkane dehalogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.8.1.5 3.8.1.5] </span></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=5uy1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5uy1 OCA], [http://pdbe.org/5uy1 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5uy1 RCSB], [http://www.ebi.ac.uk/pdbsum/5uy1 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5uy1 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://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. | + | [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. |
| - | <div style="background-color:#fffaf0;">
| + | |
| - | == 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.
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| - | 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>
| + | ==See Also== |
| - | | + | *[[Dehalogenase 3D structures|Dehalogenase 3D structures]] |
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| + | |
| - | </div>
| + | |
| - | <div class="pdbe-citations 5uy1" style="background-color:#fffaf0;"></div>
| + | |
| - | == References == | + | |
| - | <references/>
| + | |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacterium mycoides roseum grotenfelt 1889]] | + | [[Category: Large Structures]] |
| - | [[Category: Haloalkane dehalogenase]] | + | [[Category: Rhodococcus rhodochrous]] |
| - | [[Category: Boal, A K]] | + | [[Category: Boal AK]] |
| - | [[Category: Dunham, N P]] | + | [[Category: Dunham NP]] |
| - | [[Category: Fluorogenic]]
| + | |
| - | [[Category: Halo]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Tag]]
| + | |
