6JC5

Crystal structure of the blue fluorescent protein with a Leu-Leu-Gly tri-peptide chromophore derived from the purple chromoprotein of Stichodactyla haddoni

Summary for 6JC5

• Entry DOI: 10.2210/pdb6jc5/pdb
• Related: 6JC6
• Descriptor: shBFP (2 entities in total)
• Functional Keywords: sea anemone, green fluorescent protein, uv absorption, emission spectra, biomarker, fluorescent protein
• Biological source: Stichodactyla haddoni
• Total number of polymer chains: 8
• Total formula weight: 208670.98

Authors

Ko, T.P.,Huang, K.F.,Chang, H.Y. (deposition date: 2019-01-28, release date: 2019-03-20, Last modification date: 2023-11-22)

Primary citation

Chang, H.Y.,Ko, T.P.,Chang, Y.C.,Huang, K.F.,Lin, C.Y.,Chou, H.Y.,Chiang, C.Y.,Tsai, H.J.
Crystal structure of the blue fluorescent protein with a Leu-Leu-Gly tri-peptide chromophore derived from the purple chromoprotein of Stichodactyla haddoni.
Int. J. Biol. Macromol., 130:675-684, 2019

PubMed Abstract: Chromoproteins are a good source of engineered biological tools. We previously reported the development of a blue fluorescent protein, termed shBFP, which was derived from a purple chromoprotein shCP found in the sea anemone Stichodacyla haddoni. shBFP contains a Leu-Leu-Gly tri-peptide chromophore, and shows maximum excitation and emission wavelengths at 401 nm and 458 nm, along with a high quantum yield. How this chromophore endows shBFP with the unique fluorescence property in the absence of a hydroxyphenyl ring remained unclear. Here, we present the crystal structures of shCP and shBFP at 1.9- and 2.05-Å resolution, respectively. Both proteins crystallized as similar tetramers, but they are more likely to function as dimers in solution. The chromophore in shCP shows a trans-conformation and its non-planarity is similar to most other homologues. The shBFP chromophore also contains an imidazolidone moiety in its structure, but there are a smaller number of conjugated double bonds compared to shCP. Consequently, the chromophore may prefer absorbing shorter wavelength lights in the UV region, followed by the emission of blue fluorescence. These observations provide new insights into the molecular basis that correlates chromophore conformation with light absorption and fluorescence emission for the development of improved biomarkers.

PubMed: 30836182
DOI: 10.1016/j.ijbiomac.2019.02.138

Experimental method

X-RAY DIFFRACTION (2.051 Å)