X-ray Radiation Induces Deprotonation of the Bilin Chromophore in Crystalline D. Radiodurans Phytochrome

Journal Article · Wed Feb 04 00:00:00 EST 2015 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja510923m· OSTI ID:1229516

Li, Feifei ^[1]; Burgie, E. Sethe ^[2]; Yu, Tao ^[3]; Heroux, Annie ^[4]; Schatz, George C. ^[3]; Vierstra, Richard D. ^[2]; Orville, Allen M. ^[4]

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1. Brookhaven National Lab. (BNL), Upton, NY (United States); New Mexico State Univ., Las Cruces, NM (United States)
2. Univ. of Wisconsin, Madison, WI (United States)
3. Northwestern Univ., Evanston, IL (United States)
4. Brookhaven National Lab. (BNL), Upton, NY (United States)

We report that in the red light-absorbing (Pr) state, the bilin chromophore of the Deinococcus radiodurans proteobacterial phytochrome (DrBphP) is hypersensitive to X-ray photons used in typical synchrotron X-ray protein crystallography experiments. This causes the otherwise fully protonated chromophore to deprotonate without additional major structural changes. Furthermore, these results have major implications for our understanding of the structural and chemical characteristics of the resting and intermediate states of phytochromes and other photoreceptor proteins.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: SC00112704
• OSTI ID: 1229516
• Report Number(s): BNL-111592-2015-JA
• Journal Information: Journal of the American Chemical Society, Vol. 137, Issue 8; ISSN 0002-7863
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English