Related Experiment Video
Updated: Sep 3, 2025

Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping
Published on: October 24, 2014
Conserved histidine and tyrosine determine spectral responses through the water network in Deinococcus radiodurans
Heli Lehtivuori1,2, Jessica Rumfeldt3, Satu Mustalahti4
1Nanoscience Center, Department of Physics, University of Jyvaskyla, 40014, Jyvaskyla, Finland.
Abstract:
Phytochromes are red light-sensing photoreceptor proteins that bind a bilin chromophore. Here, we investigate the role of a conserved histidine (H260) and tyrosine (Y263) in the chromophore-binding domain (CBD) of Deinococcus radiodurans phytochrome (DrBphP). Using crystallography, we show that in the H260A variant, the missing imidazole side chain leads to increased water content in the binding pocket. On the other hand, Y263F mutation reduces the water occupancy around the chromophore. Together, these changes in water coordination alter the protonation and spectroscopic properties of the biliverdin. These results pinpoint the importance of this conserved histidine and tyrosine, and the related water network, for the function and applications of phytochromes.
More Related Videos
11:55In Vitro Reconstitution of Light-harvesting Complexes of Plants and Green Algae
Published on: October 10, 2014
10:31Residue-Specific Exchange of Proline by Proline Analogs in Fluorescent Proteins: How "Molecular Surgery" of the Backbone Affects Folding and Stability
Published on: February 3, 2022
Related Concept Videos
Channel Rhodopsins
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
The Antenna Complex
Photoreceptors and Plant Responses to Light
The Photochemical Reaction Center
Cell Signaling in Plants
Biological Clocks and Seasonal Responses