4Q0I

Deinococcus radiodurans BphP PAS-GAF D207A mutant

4Q0I の概要

• エントリーDOI: 10.2210/pdb4q0i/pdb
• 関連するPDBエントリー: 4Q0H 4Q0J
• 分子名称: Bacteriophytochrome, ISOPROPYL ALCOHOL, 3-[2-[(Z)-[3-(2-carboxyethyl)-5-[(Z)-(4-ethenyl-3-methyl-5-oxidanylidene-pyrrol-2-ylidene)methyl]-4-methyl-pyrrol-1-ium -2-ylidene]methyl]-5-[(Z)-[(3E)-3-ethylidene-4-methyl-5-oxidanylidene-pyrrolidin-2-ylidene]methyl]-4-methyl-1H-pyrrol-3- yl]propanoic acid, ... (4 entities in total)
• 機能のキーワード: pas gaf, photosensor, response regulator, transferase
• 由来する生物種: Deinococcus radiodurans R1
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 37686.10

構造登録者

Burgie, E.S.,Vierstra, R.D. (登録日: 2014-04-02, 公開日: 2014-07-16, 最終更新日: 2024-10-30)

主引用文献

Burgie, E.S.,Wang, T.,Bussell, A.N.,Walker, J.M.,Li, H.,Vierstra, R.D.
Crystallographic and Electron Microscopic Analyses of a Bacterial Phytochrome Reveal Local and Global Rearrangements during Photoconversion.
J.Biol.Chem., 289:24573-24587, 2014

PubMed Abstract: Phytochromes are multidomain photoswitches that drive light perception in plants and microorganisms by coupling photoreversible isomerization of their bilin chromophore to various signaling cascades. How changes in bilin conformation affect output by these photoreceptors remains poorly resolved and might include several species-specific routes. Here, we present detailed three-dimensional models of the photosensing module and a picture of an entire dimeric photoreceptor through structural analysis of the Deinococcus radiodurans phytochrome BphP assembled with biliverdin (BV). A 1.16-Å resolution crystal structure of the bilin-binding pocket in the dark-adapted red light-absorbing state illuminated the intricate network of bilin/protein/water interactions and confirmed the protonation and ZZZssa conformation of BV. Structural and spectroscopic comparisons with the photochemically compromised D207A mutant revealed that substitutions of Asp-207 allow inclusion of cyclic porphyrins in addition to BV. A crystal structure of the entire photosensing module showed a head-to-head, twisted dimeric arrangement with bowed helical spines and a hairpin protrusion connecting the cGMP phosphodiesterase/adenylyl cyclase/FhlA (GAF) and phytochrome-specific (PHY) domains. A key conserved hairpin feature is its anti-parallel, two β-strand stem, which we show by mutagenesis to be critical for BphP photochemistry. Comparisons of single particle electron microscopic images of the full-length BphP dimer in the red light-absorbing state and the photoactivated far-red light-absorbing state revealed a large scale reorientation of the PHY domain relative to the GAF domain, which alters the position of the downstream histidine kinase output module. Together, our data support a toggle model whereby bilin photoisomerization alters GAF/PHY domain interactions through conformational modification of the hairpin, which regulates signaling by impacting the relationship between sister output modules.

PubMed: 25006244
DOI: 10.1074/jbc.M114.571661

実験手法

X-RAY DIFFRACTION (1.744 Å)