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ID 46924
フルテキストURL
著者
Kawakami, Keisuke Department of Chemistry, Graduate School of Science, and The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University
Umena, Yasufumi Department of Chemistry, Graduate School of Science, and The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University
Kamiya, Nobuo Department of Chemistry, Graduate School of Science, and The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University
Shen, Jian-Ren Division of Bioscience, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University
抄録
The catalytic center for photosynthetic water-splitting consists of 4 Mn atoms and 1 Ca atom and is located near the lumenal surface of photosystem II. So far the structure of the Mn(4)Ca-cluster has been studied by a variety of techniques including X-ray spectroscopy and diffraction, and various structural models have been proposed. However, its exact structure is still unknown due to the limited resolution of crystal structures of PSII achieved so far, as well as possible radiation damages that might have occurred. Very recently, we have succeeded in solving the structure of photosystem II at 1.9 angstrom. which yielded a detailed picture of the Mn(4)CaO(5)-cluster for the first time. In the high resolution structure, the Mn(4)CaO(5)-cluster is arranged in a distorted chair form, with a cubane-like structure formed by 3 Mn and 1 Ca, 4 oxygen atoms as the distorted base of the chair, and 1 Mn and 1 oxygen atom outside of the cubane as the back of the chair. In addition, four water molecules were associated with the cluster, among which, two are associated with the terminal Mn atom and two are associated with the Ca atom. Some of these water molecules may therefore serve as the substrates for water-splitting. The high resolution structure of the catalytic center provided a solid basis for elucidation of the mechanism of photosynthetic water splitting. We review here the structural features of the Mn(4)CaO(5)-cluster analyzed at 1.9 angstrom resolution, and compare them with the structures reported previously.
キーワード
Crystal structure
Membrane protein structure
Oxygen-evolving complex
Photosystem II
Water-oxidation
発行日
2011
出版物タイトル
Journal of Photochemistry and Photobiology B: Biology
104巻
1-2号
出版者
Elsevier Science SA.
開始ページ
9
終了ページ
18
ISSN
1011-1344
NCID
AA10686173
資料タイプ
学術雑誌論文
プロジェクト
エネルギー環境新素材拠点
言語
English
OAI-PMH Set
岡山大学
著作権者
© 2011 Elsevier B.V. All rights reserved.
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