View source for 6t39


==Crystal structure of rsEGFP2 in its off-state determined by SFX==
<StructureSection load='6t39' size='340' side='right'caption='[[6t39]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6t39]] 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=6T39 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6T39 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]] 1.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PIA:[(4Z)-2-[(1S)-1-AMINOETHYL]-4-(4-HYDROXYBENZYLIDENE)-5-OXO-4,5-DIHYDRO-1H-IMIDAZOL-1-YL]ACETIC+ACID'>PIA</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=6t39 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6t39 OCA], [https://pdbe.org/6t39 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6t39 RCSB], [https://www.ebi.ac.uk/pdbsum/6t39 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6t39 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 ==
Reversibly switchable fluorescent proteins (RSFPs) serve as markers in advanced fluorescence imaging. Photoswitching from a non-fluorescent off-state to a fluorescent on-state involves trans-to-cis chromophore isomerization and proton transfer. Whereas excited-state events on the ps timescale have been structurally characterized, conformational changes on slower timescales remain elusive. Here we describe the off-to-on photoswitching mechanism in the RSFP rsEGFP2 by using a combination of time-resolved serial crystallography at an X-ray free-electron laser and ns-resolved pump-probe UV-visible spectroscopy. Ten ns after photoexcitation, the crystal structure features a chromophore that isomerized from trans to cis but the surrounding pocket features conformational differences compared to the final on-state. Spectroscopy identifies the chromophore in this ground-state photo-intermediate as being protonated. Deprotonation then occurs on the mus timescale and correlates with a conformational change of the conserved neighbouring histidine. Together with a previous excited-state study, our data allow establishing a detailed mechanism of off-to-on photoswitching in rsEGFP2.

Photoswitching mechanism of a fluorescent protein revealed by time-resolved crystallography and transient absorption spectroscopy.,Woodhouse J, Nass Kovacs G, Coquelle N, Uriarte LM, Adam V, Barends TRM, Byrdin M, de la Mora E, Bruce Doak R, Feliks M, Field M, Fieschi F, Guillon V, Jakobs S, Joti Y, Macheboeuf P, Motomura K, Nass K, Owada S, Roome CM, Ruckebusch C, Schiro G, Shoeman RL, Thepaut M, Togashi T, Tono K, Yabashi M, Cammarata M, Foucar L, Bourgeois D, Sliwa M, Colletier JP, Schlichting I, Weik M Nat Commun. 2020 Feb 6;11(1):741. doi: 10.1038/s41467-020-14537-0. PMID:32029745<ref>PMID:32029745</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6t39" 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: Adam V]]
[[Category: Barends TRM]]
[[Category: Bourgeois D]]
[[Category: Colletier JP]]
[[Category: Coquelle N]]
[[Category: De La Mora E]]
[[Category: Schlichting I]]
[[Category: Weik M]]
[[Category: Woodhouse J]]