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Green/red light-sensing mechanism in the chromatic acclimation photosensor.
- Source :
-
Science advances [Sci Adv] 2024 Jun 14; Vol. 10 (24), pp. eadn8386. Date of Electronic Publication: 2024 Jun 12. - Publication Year :
- 2024
-
Abstract
- Certain cyanobacteria alter their photosynthetic light absorption between green and red, a phenomenon called complementary chromatic acclimation. The acclimation is regulated by a cyanobacteriochrome-class photosensor that reversibly photoconverts between green-absorbing (Pg) and red-absorbing (Pr) states. Here, we elucidated the structural basis of the green/red photocycle. In the Pg state, the bilin chromophore adopted the extended C15- Z , anti structure within a hydrophobic pocket. Upon photoconversion to the Pr state, the bilin is isomerized to the cyclic C15- E , syn structure, forming a water channel in the pocket. The solvation/desolvation of the bilin causes changes in the protonation state and the stability of π-conjugation at the B ring, leading to a large absorption shift. These results advance our understanding of the enormous spectral diversity of the phytochrome superfamily.
Details
- Language :
- English
- ISSN :
- 2375-2548
- Volume :
- 10
- Issue :
- 24
- Database :
- MEDLINE
- Journal :
- Science advances
- Publication Type :
- Academic Journal
- Accession number :
- 38865454
- Full Text :
- https://doi.org/10.1126/sciadv.adn8386