5B66

Crystal structure analysis of Photosystem II complex

5B66 の概要

• エントリーDOI: 10.2210/pdb5b66/pdb
• 関連するPDBエントリー: 5B5E
• 分子名称: Photosystem II protein D1, Photosystem II reaction center protein K, Photosystem II reaction center protein L, ... (41 entities in total)
• 機能のキーワード: psii, photosystem, oxygen evolving, water splitting, thylakoid membrane, electron transport, photosynthesis
• 由来する生物種: Thermosynechococcus vulcanus; 詳細
• タンパク質・核酸の鎖数: 38
• 化学式量合計: 744331.15

構造登録者

Tanaka, A.,Fukushima, Y.,Kamiya, N. (登録日: 2016-05-25, 公開日: 2017-02-01, 最終更新日: 2024-10-23)

主引用文献

Tanaka, A.,Fukushima, Y.,Kamiya, N.
Two Different Structures of the Oxygen-Evolving Complex in the Same Polypeptide Frameworks of Photosystem II
J. Am. Chem. Soc., 139:1718-1721, 2017

PubMed Abstract: The oxygen-evolving complex (OEC) forms the heart of photosystem II (PSII) in photosynthesis. The crystal structure of PSII from Thermosynechococcus vulcanus has been reported at a resolution of 1.9 Å and at an averaged X-ray dose of 0.43 MGy. The OEC structure is suggested to be partially reduced to Mn(II) by EXAFS and DFT computational studies. Recently, the "radiation-damage-free" structures have been published at 1.95 Å resolution using XFEL, but reports continued to appear that the OEC is reduced to the S-state of the Kok cycle. To elucidate much more precise structure of the OEC, in this study two structures were determined at extremely low X-ray doses of 0.03 and 0.12 MGy using conventional synchrotron radiation source. The results indicated that the X-ray reduction effects on the OEC were very small in the low dose region below 0.12 MGy, that is, a threshold existed for the OEC structural changes caused by X-ray exposure. The OEC structures of the two identical monomers in the crystal were clearly different under the threshold of the radiation dose, although the surrounding polypeptide frameworks of PSII were the same. The assumption that the OECs in the crystal were in the dark-stable S-state of the Kok cycle should be re-evaluated.

PubMed: 28102667
DOI: 10.1021/jacs.6b09666

実験手法

X-RAY DIFFRACTION (1.85 Å)