Orientation of a Key Glutamine Residue in the BLUF Domain from AppA Revealed by Mutagenesis,Spectroscopy,and Quantum Chemical Calculations

摘要

In many biological photoreceptors,such as rhodopsins,phyto-chromes,photoactive yellow protein,and phototropins,gross structural changes are photoinduced in the chromophore molecule,which triggers a series of protein structural changes that ultimately lead to a formation of a signaling state.In contrast,flavin-containing BLUF (blue-light using flavin-adenine-dinucleotide (FAD))proteins show a different photoactivation mechanism that is not accompanied with the prominent structural changes of the chromophore molecule.