Light-induced structural changes in a monomeric bacteriophytochrome.

摘要: Phytochromes sense red light in plants and various microorganism. Light absorption causes structural changes within the protein, which alter its biochemical activity. Bacterial phytochromes are dimeric proteins, but functional relevance of this arrangement remains unclear. Here, we use time-resolved X-ray scattering to reveal solution change a monomeric variant photosensory core module phytochrome from Deinococcus radiodurans. The data two motions, bend twist PHY domain with respect chromophore-binding domains. Infrared spectroscopy shows refolding tongue. We conclude that monomer is sufficient perform light-induced changes. This implies allosteric cooperation other not needed for activation. may instead be intrinsic output domains bacterial phytochromes.