6NQQ

Crystal structure of fast switching M159T mutant of fluorescent protein Dronpa (Dronpa2), Y63(2,3,5-F3Y)

Summary for 6NQQ

• Entry DOI: 10.2210/pdb6nqq/pdb
• Descriptor: Fluorescent protein Dronpa (2 entities in total)
• Functional Keywords: dronpa2, fluorescent protein
• Biological source: Echinophyllia sp. SC22
• Total number of polymer chains: 8
• Total formula weight: 232124.39

Authors

Lin, C.-Y.,Romei, M.G.,Mathews, I.I.,Boxer, S.G. (deposition date: 2019-01-21, release date: 2019-06-12, Last modification date: 2023-11-15)

Primary citation

Romei, M.G.,Lin, C.Y.,Mathews, I.I.,Boxer, S.G.
Electrostatic control of photoisomerization pathways in proteins.
Science, 367:76-79, 2020

PubMed Abstract: Rotation around a specific bond after photoexcitation is central to vision and emerging opportunities in optogenetics, super-resolution microscopy, and photoactive molecular devices. Competing roles for steric and electrostatic effects that govern bond-specific photoisomerization have been widely discussed, the latter originating from chromophore charge transfer upon excitation. We systematically altered the electrostatic properties of the green fluorescent protein chromophore in a photoswitchable variant, Dronpa2, using amber suppression to introduce electron-donating and electron-withdrawing groups to the phenolate ring. Through analysis of the absorption (color), fluorescence quantum yield, and energy barriers to ground- and excited-state isomerization, we evaluate the contributions of sterics and electrostatics quantitatively and demonstrate how electrostatic effects bias the pathway of chromophore photoisomerization, leading to a generalized framework to guide protein design.

PubMed: 31896714
DOI: 10.1126/science.aax1898

Experimental method

X-RAY DIFFRACTION (2.6 Å)