7z9d
Deinococcus radiodurans BphP PAS-GAF H260A mutant
Structural highlights
FunctionBPHY_DEIRA Photoreceptor which exists in two forms that are reversibly interconvertible by light: the R form that absorbs maximally in the red region of the spectrum and the FR form that absorbs maximally in the far-red region. Has also a slight blue shift for the far-red maximum. Could also absorb green light. May participate in regulating pigment synthesis like the carotenoid deinoxanthin which could protect the bacterium from intense visible light. Publication Abstract from PubMedPhytochromes 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. Conserved histidine and tyrosine determine spectral responses through the water network in Deinococcus radiodurans phytochrome.,Lehtivuori H, Rumfeldt J, Mustalahti S, Kurkinen S, Takala H Photochem Photobiol Sci. 2022 Jul 29. pii: 10.1007/s43630-022-00272-6. doi:, 10.1007/s43630-022-00272-6. PMID:35906527[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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