3VK1

Green-fluorescent variant of the non-fluorescent chromoprotein Rtms5

Summary for 3VK1

• Entry DOI: 10.2210/pdb3vk1/pdb
• Related: 1MOU 1MOV 2ARL 2P4M 3VIC
• Descriptor: GFP-like non-fluorescent chromoprotein, IODIDE ION, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: gfp, anthozoa, beta can, beta barrel, fluorescent protein, pigment protein, pigment, pocilloporin, chromoprotein, luminescent protein, fluorophore, chromophore, acylimine
• Biological source: Montipora efflorescens (Coral)
• Total number of polymer chains: 1
• Total formula weight: 27308.91

Authors

Battad, J.M.,Traore, D.A.K.,Wilce, M.,Byres, M.,Rossjohn, J.,Devenish, R.J.,Prescott, M. (deposition date: 2011-11-07, release date: 2012-06-06, Last modification date: 2024-10-16)

Primary citation

Battad, J.M.,Traore, D.A.,Byres, E.,Rossjohn, J.,Devenish, R.J.,Olsen, S.,Wilce, M.C.,Prescott, M.
A Green Fluorescent Protein Containing a QFG Tri-Peptide Chromophore: Optical Properties and X-Ray Crystal Structure.
Plos One, 7:e47331-e47331, 2012

PubMed Abstract: Rtms5 is an deep blue weakly fluorescent GFP-like protein ([Formula: see text], 592 nm; [Formula: see text], 630nm; Φ(F), 0.004) that contains a (66)Gln-Tyr-Gly chromophore tripeptide sequence. We investigated the optical properties and structure of two variants, Rtms5(Y67F) and Rtms5(Y67F/H146S) in which the tyrosine at position 67 was substituted by a phenylalanine. Compared to the parent proteins the optical spectra for these new variants were significantly blue-shifted. Rtms5(Y67F) spectra were characterised by two absorbing species ([Formula: see text], 440 nm and 513 nm) and green fluorescence emission ([Formula: see text], 440 nm; [Formula: see text], 508 nm; Φ(F), 0.11), whilst Rtms5(Y67F/H146S) spectra were characterised by a single absorbing species ([Formula: see text], 440 nm) and a relatively high fluorescence quantum yield (Φ(F,) 0.75; [Formula: see text], 440 nm; [Formula: see text], 508 nm). The fluorescence emissions of each variant were remarkably stable over a wide range of pH (3-11). These are the first GFP-like proteins with green emissions (500-520 nm) that do not have a tyrosine at position 67. The X-ray crystal structure of each protein was determined to 2.2 Å resolution and showed that the benzylidine ring of the chromophore, similar to the 4-hydroxybenzylidine ring of the Rtms5 parent, is non-coplanar and in the trans conformation. The results of chemical quantum calculations together with the structural data suggested that the 513 nm absorbing species in Rtms5(Y67F) results from an unusual form of the chromophore protonated at the acylimine oxygen. These are the first X-ray crystal structures for fluorescent proteins with a functional chromophore containing a phenylalanine at position 67.

PubMed: 23071789
DOI: 10.1371/journal.pone.0047331

Experimental method

X-RAY DIFFRACTION (2.2 Å)