English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Cryptochromes are ubiquitous flavin-binding light sensors closely related to DNA-repairing photolyases. The animal-like cryptochrome Cr aCRY from the green alga Chlamydomonas reinhardtii challenges the paradigm of cryptochromes as pure blue-light receptors by acting as a (6-4) photolyase, using 8-hydroxy-5-deazaflavin (8-HDF) as a light-harvesting antenna with a 17.4 Å distance to flavin and showing spectral sensitivity up to 680 nm. The expanded action spectrum is attributed to the presence of the flavin neutral radical (FADH • ) in the dark, despite a rapid FADH • decay observed in vitro in samples exclusively carrying flavin. Herein, the red-light response of Cr aCRY carrying flavin and 8-HDF was studied, revealing a 3-fold prolongation of the FADH • lifetime in the presence of 8-HDF. Millisecond time-resolved ultraviolet-visible spectroscopy showed the red-light-induced formation and decay of an absorbance band at 458 nm concomitant with flavin reduction. Time-resolved Fourier transform infrared (FTIR) spectroscopy and density functional theory attributed these changes to the deprotonation of 8-HDF, challenging the paradigm of 8-HDF being permanently deprotonated in photolyases. FTIR spectra showed changes in the hydrogen bonding network of asparagine 395, a residue suggested to indirectly control flavin protonation, indicating the involvement of N395 in the stabilization of FADH • . Fluorescence spectroscopy revealed a decrease in the energy transfer efficiency of 8-HDF upon flavin reduction, possibly linked to 8-HDF deprotonation. The discovery of the interdependence of flavin and 8-HDF beyond energy transfer processes highlights the essential role of the antenna, introducing a new concept enabling Cr aCRY and possibly other bifunctional cryptochromes to fulfill their dual function.

Interconnection of the Antenna Pigment 8-HDF and Flavin Facilitates Red-Light Reception in a Bifunctional Animal-like Cryptochrome