Ultrafast red light activation of Synechocystis phytochrome Cph1 triggers major structural change to form the Pfr signalling-competent state.

ABSTRACT: Phytochromes are dimeric photoreceptors that regulate a range of responses in plants and microorganisms through interconversion of red light-absorbing (Pr) and far-red light-absorbing (Pfr) states. Photoconversion between these states is initiated by light-driven isomerization of a bilin cofactor, which triggers protein structural change. The extent of this change, and how light-driven structural changes in the N-terminal photosensory region are transmitted to the C-terminal regulatory domain to initiate the signalling cascade, is unknown. We have used pulsed electron-electron double resonance (PELDOR) spectroscopy to identify multiple structural transitions in a phytochrome from Synechocystis sp. PCC6803 (Cph1) by measuring distances between nitroxide labels introduced into the protein. W

SUBMITTER: Heyes DJ 

PROVIDER: S-EPMC3530517 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature