5k5b
From Proteopedia
Wild-type PAS-GAF fragment from Deinococcus radiodurans BphP
Structural highlights
Function[BPHY_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 a family of photoreceptors that control light responses of plants, fungi and bacteria. A sequence of structural changes, which is not yet fully understood, leads to activation of an output domain. Time-resolved serial femtosecond crystallography (SFX) can potentially shine light on these conformational changes. Here we report the room temperature crystal structure of the chromophore-binding domains of the Deinococcus radiodurans phytochrome at 2.1 A resolution. The structure was obtained by serial femtosecond X-ray crystallography from microcrystals at an X-ray free electron laser. We find overall good agreement compared to a crystal structure at 1.35 A resolution derived from conventional crystallography at cryogenic temperatures, which we also report here. The thioether linkage between chromophore and protein is subject to positional ambiguity at the synchrotron, but is fully resolved with SFX. The study paves the way for time-resolved structural investigations of the phytochrome photocycle with time-resolved SFX. The room temperature crystal structure of a bacterial phytochrome determined by serial femtosecond crystallography.,Edlund P, Takala H, Claesson E, Henry L, Dods R, Lehtivuori H, Panman M, Pande K, White T, Nakane T, Berntsson O, Gustavsson E, Bath P, Modi V, Roy-Chowdhury S, Zook J, Berntsen P, Pandey S, Poudyal I, Tenboer J, Kupitz C, Barty A, Fromme P, Koralek JD, Tanaka T, Spence J, Liang M, Hunter MS, Boutet S, Nango E, Moffat K, Groenhof G, Ihalainen J, Stojkovic EA, Schmidt M, Westenhoff S Sci Rep. 2016 Oct 19;6:35279. doi: 10.1038/srep35279. PMID:27756898[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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