X-ray 3D structures of native green and photoconverted red forms of DendFP (Dendronephthya sp.)
What is it about?
The fluorescence of wt DendFP irreversibly transforms from green (506 nm) to red (578 nm) upon irradiation with UV-light. We presented the X-ray structures of the wild type DendFP in green and photoconverted red forms. Under UV-blue-light irradiation DendFP undergoes an irreversible green-to-red photoconversion resulting in formation of double CA=CB bond in the chromophore His62 and a cleavage of the peptide backbone at its Cα–N bond. The combination of the key structural features was shown to be important for the fluorescence and photoconversion of DendFP. The study has been supported by structure based site directed mutagenesis.
Why is it important?
Based on mutagenesis a strong correlation between the chromophore protonation degree and the protein photoconversion rate (PC) has been shown. Design of new gene-engineering variants with a considerable increase of PC has been done.