View source for 4ppk


==Crystal structure of eCGP123 T69V variant at pH 7.5==
<StructureSection load='4ppk' size='340' side='right'caption='[[4ppk]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4ppk]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4PPK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4PPK 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&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CRQ:[2-(3-CARBAMOYL-1-IMINO-PROPYL)-4-(4-HYDROXY-BENZYLIDENE)-5-OXO-4,5-DIHYDRO-IMIDAZOL-1-YL]-ACETIC+ACID'>CRQ</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=4ppk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ppk OCA], [https://pdbe.org/4ppk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ppk RCSB], [https://www.ebi.ac.uk/pdbsum/4ppk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ppk ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Phanta is a reversibly photoswitching chromoprotein (PhiF, 0.003), useful for pcFRET, that was isolated from a mutagenesis screen of the bright green fluorescent eCGP123 (PhiF, 0.8). We have investigated the contribution of substitutions at positions His193, Thr69 and Gln62, individually and in combination, to the optical properties of Phanta. Single amino acid substitutions at position 193 resulted in proteins with very low PhiF, indicating the importance of this position in controlling the fluorescence efficiency of the variant proteins. The substitution Thr69Val in Phanta was important for supressing the formation of a protonated chromophore species observed in some His193 substituted variants, whereas the substitution Gln62Met did not significantly contribute to the useful optical properties of Phanta. X-ray crystal structures for Phanta (2.3 A), eCGP123T69V (2.0 A) and eCGP123H193Q (2.2 A) in their non-photoswitched state were determined, revealing the presence of a cis-coplanar chromophore. We conclude that changes in the hydrogen-bonding network supporting the cis-chromophore, and its contacts with the surrounding protein matrix, are responsible for the low fluorescence emission of eCGP123 variants containing a His193 substitution.

X-Ray Crystal Structure and Properties of Phanta, a Weakly Fluorescent Photochromic GFP-Like Protein.,Don Paul C, Traore DA, Olsen S, Devenish RJ, Close DW, Bell TD, Bradbury A, Wilce MC, Prescott M PLoS One. 2015 Apr 29;10(4):e0123338. doi: 10.1371/journal.pone.0123338., eCollection 2015. PMID:25923520<ref>PMID:25923520</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4ppk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Bell T]]
[[Category: Bradbury A]]
[[Category: Close D]]
[[Category: Devenish RJ]]
[[Category: Don Paul C]]
[[Category: Prescott M]]
[[Category: Traore DAK]]
[[Category: Wilce MCJ]]