View source for 6pfr


==rsEGFP2 with a chlorinated chromophore in the fluorescent on-state==
<StructureSection load='6pfr' size='340' side='right'caption='[[6pfr]], [[Resolution|resolution]] 1.51&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6pfr]] 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=6PFR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6PFR 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]] 1.51&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=OHD:2-[(4~{Z})-2-[(1~{S})-1-azanylethyl]-4-[(3-chloranyl-4-oxidanyl-phenyl)methylidene]-5-oxidanylidene-imidazol-1-yl]ethanoic+acid'>OHD</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=6pfr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6pfr OCA], [https://pdbe.org/6pfr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6pfr RCSB], [https://www.ebi.ac.uk/pdbsum/6pfr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6pfr 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.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Double-bond photoisomerization in molecules such as the green fluorescent protein (GFP) chromophore can occur either via a volume-demanding one-bond-flip pathway or via a volume-conserving hula-twist pathway. Understanding the factors that determine the pathway of photoisomerization would inform the rational design of photoswitchable GFPs as improved tools for super-resolution microscopy. In this communication, we reveal the photoisomerization pathway of a photoswitchable GFP, rsEGFP2, by solving crystal structures of cis and trans rsEGFP2 containing a monochlorinated chromophore. The position of the chlorine substituent in the trans state breaks the symmetry of the phenolate ring of the chromophore and allows us to distinguish the two pathways. Surprisingly, we find that the pathway depends on the arrangement of protein monomers within the crystal lattice: in a looser packing, the one-bond-flip occurs, whereas, in a tighter packing (7% smaller unit cell size), the hula-twist occurs.

Structural Evidence of Photoisomerization Pathways in Fluorescent Proteins.,Chang J, Romei MG, Boxer SG J Am Chem Soc. 2019 Oct 2;141(39):15504-15508. doi: 10.1021/jacs.9b08356. Epub, 2019 Sep 24. PMID:31533429<ref>PMID:31533429</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6pfr" 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: Boxer SG]]
[[Category: Chang J]]
[[Category: Romei MG]]