4PPK
Crystal structure of eCGP123 T69V variant at pH 7.5
Summary for 4PPK
| Entry DOI | 10.2210/pdb4ppk/pdb |
| Related | 4PPJ 4PPL |
| Descriptor | Monomeric Azami Green (2 entities in total) |
| Functional Keywords | gfp, fluorescent protein, chromophore, photoswitching |
| Biological source | SYNTHETIC CONSTRUCT |
| Total number of polymer chains | 4 |
| Total formula weight | 113016.90 |
| Authors | Don Paul, C.,Traore, D.A.K.,Devenish, R.J.,Close, D.,Bell, T.,Bradbury, A.,Wilce, M.C.J.,Prescott, M. (deposition date: 2014-02-27, release date: 2015-04-08, Last modification date: 2024-10-16) |
| Primary citation | Don Paul, C.,Traore, D.A.,Olsen, S.,Devenish, R.J.,Close, D.W.,Bell, T.D.,Bradbury, A.,Wilce, M.C.,Prescott, M. X-Ray Crystal Structure and Properties of Phanta, a Weakly Fluorescent Photochromic GFP-Like Protein. Plos One, 10:e0123338-e0123338, 2015 Cited by PubMed Abstract: Phanta is a reversibly photoswitching chromoprotein (ΦF, 0.003), useful for pcFRET, that was isolated from a mutagenesis screen of the bright green fluorescent eCGP123 (ΦF, 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 ΦF, 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 Å), eCGP123T69V (2.0 Å) and eCGP123H193Q (2.2 Å) 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. PubMed: 25923520DOI: 10.1371/journal.pone.0123338 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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