@article{809ede52afd0479e858e8846cdf74c8b,
title = "High-resolution crystal structures of a myxobacterial phytochrome at cryo and room temperatures",
abstract = "Phytochromes (PHYs) are photoreceptor proteins first discovered in plants, where they control a variety of photomorphogenesis events. PHYs as photochromic proteins can reversibly switch between two distinct states: a red light (Pr) and a far-red light (Pfr) absorbing form. The discovery of Bacteriophytochromes (BphPs) in nonphotosynthetic bacteria has opened new frontiers in our understanding of the mechanisms by which these natural photoswitches can control single cell development, although the role of BphPs in vivo remains largely unknown. BphPs are dimeric proteins that consist of a photosensory core module (PCM) and an enzymatic domain, often a histidine kinase. The PCM is composed of three domains (PAS, GAF, and PHY). It holds a covalently bound open-chain tetrapyrrole (biliverdin, BV) chromophore. Upon absorption of light, the double bond between BV rings C and D isomerizes and reversibly switches the protein between Pr and Pfr states. We report crystal structures of the wild-type and mutant (His275Thr) forms of the canonical BphP from the nonphotosynthetic myxobacterium Stigmatella aurantiaca (SaBphP2) in the Pr state. Structures were determined at 1.65 {\AA} and 2.2 {\AA} (respectively), the highest resolution of any PCM construct to date. We also report the room temperature wild-type structure of the same protein determined at 2.1 {\AA} at the SPring-8 Angstrom Compact free electron LAser (SACLA), Japan. Our results not only highlight and confirm important amino acids near the chromophore that play a role in Pr-Pfr photoconversion but also describe the signal transduction into the PHY domain which moves across tens of angstroms after the light stimulus.",
author = "Sanchez, {Juan C.} and Melissa Carrillo and Suraj Pandey and Moraima Noda and Luis Aldama and Denisse Feliz and Elin Claesson and Wahlgren, {Weixiao Yuan} and Gregory Tracy and Phu Duong and Nugent, {Angela C.} and Andrew Field and Vukica {\v S}rajer and Christopher Kupitz and So Iwata and Eriko Nango and Rie Tanaka and Tomoyuki Tanaka and Luo Fangjia and Kensuke Tono and Shigeki Owada and Sebastian Westenhoff and Marius Schmidt and Stojkovi{\'c}, {Emina A.}",
note = "Funding Information: The results shown are derived from work performed at Argonne National Laboratory, Structural Biology Center at the Advanced Photon Source. Argonne is operated by UChicago Argonne, LLC, for the U.S. Department of Energy, Office of Biological and Environmental Research under Contract No. DE-AC02-06CH11 357. The experiments at SACLA were performed at BL2 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal Nos. 2018A8055 and 2019A8007). This work was supported by National Science Foundation (NSF) Science and Technology Centers (STC) under Grant No. NSF-1231306 (“Biology with X-ray Lasers”). E.A.S. was supported by NSF-MCB-RUI 1413360, NSF-MCB-EAGER Grant No. 1839513, and NSF STC BioXFEL center award 6227. M.N. and L.A. training was supported in part by the National Institute of General Medical Sciences (NIGMS) of the National Institutes of Health (NIH) Maximizing Access to Research Careers (MARC)-T34 GM105549 grant. The use of BioCARS was supported by NIH NIGMS under Grant No. P41 GM118217. This research was partially supported by the Platform Project for Supporting Drug Discovery and Life Science Research [Basis for Supporting Innovative Drug Discovery and Life Science Research (BINDS)] from Japan Agency for Medical Research and Development (AMED). Structural models as well as structure factor amplitudes were deposited in the Protein Data Bank with accession codes 6PTX, 6PTQ, and 6PU2 for the wild-type cryo, wild-type room temperature, and His275Thr mutant of SaBphP2 PCM, respectively. The authors declare that they have no competing interests. Publisher Copyright: {\textcopyright} 2019 Author(s).",
year = "2019",
month = sep,
day = "1",
doi = "10.1063/1.5120527",
language = "English",
volume = "6",
journal = "Structural Dynamics",
issn = "2329-7778",
publisher = "AAPM - American Association of Physicists in Medicine",
number = "5",
}