View source for 5ox9


==Structure of the Cyan Fluorescent Protein SCFP3A at pH 4.5==
<StructureSection load='5ox9' size='340' side='right'caption='[[5ox9]], [[Resolution|resolution]] 1.56&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ox9]] is a 1 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=5OX9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5OX9 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]] 1.56&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=B2H:2-[2-[(1~{R},2~{R})-1-azanyl-2-oxidanyl-propyl]-4-(1~{H}-indol-3-ylmethyl)-5-oxidanyl-imidazol-1-yl]ethanoic+acid'>B2H</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</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=5ox9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ox9 OCA], [https://pdbe.org/5ox9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ox9 RCSB], [https://www.ebi.ac.uk/pdbsum/5ox9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ox9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GFP_AEQVI GFP_AEQVI] Energy-transfer acceptor. Its role is to transduce the blue chemiluminescence of the protein aequorin into green fluorescent light by energy transfer. Fluoresces in vivo upon receiving energy from the Ca(2+)-activated photoprotein aequorin.
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== Publication Abstract from PubMed ==
ECFP, the first usable cyan fluorescent protein (CFP), was obtained by adapting the tyrosine-based chromophore environment in green fluorescent protein to that of a tryptophan-based one. This first-generation CFP was superseded by the popular Cerulean, CyPet, and SCFP3A that were engineered by rational and random mutagenesis, yet the latter CFPs still exhibit suboptimal properties of pH sensitivity and reversible photobleaching behavior. These flaws were serendipitously corrected in the third-generation CFP mTurquoise and its successors without an obvious rationale. We show here that the evolution process had unexpectedly remodeled the chromophore environment in second-generation CFPs so they would accommodate a different isomer, whose formation is favored by acidic pH or light irradiation and which emits fluorescence much less efficiently. Our results illustrate how fluorescent protein engineering based solely on fluorescence efficiency optimization may affect other photophysical or physicochemical parameters and provide novel insights into the rational evolution of fluorescent proteins with a tryptophan-based chromophore.

Chromophore Isomer Stabilization Is Critical to the Efficient Fluorescence of Cyan Fluorescent Proteins.,Gotthard G, von Stetten D, Clavel D, Noirclerc-Savoye M, Royant A Biochemistry. 2017 Nov 27. pii: 10.1021/acs.biochem.7b01088. doi:, 10.1021/acs.biochem.7b01088. PMID:29148725<ref>PMID:29148725</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 5ox9" style="background-color:#fffaf0;"></div>

==See Also==
*[[Green Fluorescent Protein 3D structures|Green Fluorescent Protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Aequorea victoria]]
[[Category: Large Structures]]
[[Category: Clavel D]]
[[Category: Gotthard G]]
[[Category: Noirclerc-Savoye M]]
[[Category: Royant A]]
[[Category: Von Stetten D]]