Phytochromes regulate plant growth by sensing far-red light through the photoisomerization of their protein-bound chromophores. In the phytochrome Agp2, it has now been demonstrated that ultrafast proton-transfer occurs from the chromophore to a protein–water network before photoisomerization, inducing protein changes on the ultrafast timescale. These protein changes develop further on longer timescales, resulting in an activated protein conformation.
- Yang Yang
- Till Stensitzki
- Karsten Heyne
