Circular dichroism spectroscopy reveals multiple phytochrome photoproducts in equilibrium.

ABSTRACT: Phytochromes are a widespread family of red/far-red photoreceptors including master regulators of plant growth and development. Phytochromes use 15,16-photoisomerization of linear tetrapyrrole (bilin) chromophores to toggle between a 15Z red-absorbing dark-adapted state (P_r) and a 15E far-red-absorbing photoproduct (P_fr). The bilin is bound within a conserved, N-terminal PAS-GAF-PHY photosensor tridomain and is covalently attached to a conserved Cys residue, but the mechanism(s) permitting detection of far-red light are not well understood. Plant and cyanobacterial phytochromes exhibit complex P_fr CD spectra that are also not well explained. In this work, we use the model cyanobacterial phytochrome Cph1 from Synechocystis sp. PCC 6803 to examine the basis f

SUBMITTER: Rockwell NC 

PROVIDER: S-EPMC12420706 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature