View source for 5zab


==Crystal structure of cf3-aequorin==
<StructureSection load='5zab' size='340' side='right'caption='[[5zab]], [[Resolution|resolution]] 2.15&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5zab]] is a 16 chain structure with sequence from [https://en.wikipedia.org/wiki/Aequorea_victoria Aequorea victoria]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5ZAB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5ZAB 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]] 2.147&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=9A3:(2S)-8-benzyl-2-hydroperoxy-6-(4-hydroxyphenyl)-2-{[4-(trifluoromethyl)phenyl]methyl}imidazo[1,2-a]pyrazin-3(2H)-one'>9A3</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=5zab FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5zab OCA], [https://pdbe.org/5zab PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5zab RCSB], [https://www.ebi.ac.uk/pdbsum/5zab PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5zab ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AEQ2_AEQVI AEQ2_AEQVI] Ca(2+)-dependent bioluminescence photoprotein. Displays an emission peak at 470 nm (blue light). Trace amounts of calcium ion trigger the intramolecular oxidation of the chromophore, coelenterazine into coelenteramide and CO(2) with the concomitant emission of light.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
cf3-Aequorin is one of the semi-synthetic aequorins that was produced by replacing 2-peroxycoelenterazine (CTZ-OOH) in native aequorin with a 2-peroxycoelenterazine analog, and it was prepared using the C2-modified trifluoromethyl analog of coelenterazine (cf3-CTZ) and the histidine-tagged apoaequorin expressed in Escherichia coli cells. The purified cf3-aequorin showed a slow luminescence pattern with half-decay time of Imax of 5.0 s. This is much longer than that of 0.9 s for native aequorin, and its luminescence capacity was estimated to be 72.8% of that of native aequorin. The crystal structure of cf3-aequorin was determined at 2.15 A resolution. The light source of 2-peroxytrifluoromethylcoelenterazine (cf3-CTZ-OOH) was stabilized by the hydrogen-bonding interactions at the C2-peroxy moiety and the p-hydroxy moiety at the C6-phenyl group. In native aequorin, three water molecules contribute to stabilizing CTZ-OOH through hydrogen bonds. However, cf3-aequorin only contained one water molecule, and the trifluoromethyl moiety at the C2-benzyl group of cf3-CTZ-OOH interacted with the protein by van der Waals interactions. The slow luminescence kinetics of cf3-aequorin could be explained by slow conformational changes due to the bulkiness of the trifluoromethyl group, which might hinder the smooth cleavage of hydrogen bonds at the C2-peroxy moiety after the binding of Ca2+ to cf3-aequorin.

Slow luminescence kinetics of semi-synthetic aequorin: Expression, purification and structure determination of cf3-aequorin.,Inouye S, Tomabechi Y, Hosoya T, Sekine SI, Shirouzu M J Biochem. 2018 May 23. pii: 5001758. doi: 10.1093/jb/mvy049. PMID:29796619<ref>PMID:29796619</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5zab" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Aequorea victoria]]
[[Category: Large Structures]]
[[Category: Hosoya T]]
[[Category: Inouye S]]
[[Category: Sekine SI]]
[[Category: Shirouzu M]]
[[Category: Tomabechi Y]]