Journal article

Publication year: 2011

Pages: 3842-3847

Journal: Proceedings of the National Academy of Sciences

Volume number: 108

Issue number: 10

ISSN: 0027-8424

Open access status: Green

DOI Link: https://doi.org/10.1073/pnas.1013377108

Publisher: National Academy of Sciences

Abstract: 
Phytochrome photoreceptors mediate light responses in plants and in many microorganisms. Here we report studies using H-1-C-13 magic-angle spinning NMR spectroscopy of the sensor module of cyanobacterial phytochrome Cph1. Two isoforms of the red-light absorbing Pr ground state are identified. Conclusive evidence that photoisomerization occurs at the C15-methine bridge leading to a beta-facial disposition of the ring D is presented. In the far-red-light absorbing Pfr state, strong hydrogen-bonding interactions of the D-ring carbonyl group to Tyr-263 and of N24 to Asp-207 hold the chromophore in a tensed conformation. Signaling is triggered when Asp-207 is released from its salt bridge to Arg-472, probably inducing conformational changes in the tongue region. A second signal route is initiated by partner swapping of the B-ring propionate between Arg-254 and Arg-222.

Harvard Citation style: Song, C., Psakis, G., Lang, C., Mailliet, J., Gartner, W., Hughes, J., et al. (2011) Two ground state isoforms and a chromophore D-ring photoflip triggering extensive intramolecular changes in a canonical phytochrome, Proceedings of the National Academy of Sciences, 108(10), pp. 3842-3847. https://doi.org/10.1073/pnas.1013377108

APA Citation style: Song, C., Psakis, G., Lang, C., Mailliet, J., Gartner, W., Hughes, J., & Matysik, J. (2011). Two ground state isoforms and a chromophore D-ring photoflip triggering extensive intramolecular changes in a canonical phytochrome. Proceedings of the National Academy of Sciences. 108(10), 3842-3847. https://doi.org/10.1073/pnas.1013377108