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ID 55277
フルテキストURL
著者
Motomura, Taiki the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University
Suga, Michihiro the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University
Hienerwadel, Rainer the Laboratoire de Génétique et Biophysique des Plantes, UMR 7265, CNRS-CEA-Aix-Marseille Université, Faculté des Sciences de Luminy
Nakagawa, Akiko the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University
Lai, Thanh-Lan iBiTec-S
Nitschke, Wolfgang the Laboratoire de Bioénergétique et Ingénierie des Protéines
Kuma, Takahiro the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University
Sugiura, Miwa the Proteo-Science Research Center, Ehime University
Boussac, Alain iBiTec-S
Shen, Jian-Ren the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University
抄録
Photosystem II catalyzes light-induced water oxidation leading to the generation of dioxygen indispensable for sustaining aerobic life on Earth. The Photosystem II reaction center is composed of D1 and D2 proteins encoded by psbA and psbD genes, respectively. In cyanobacteria, different psbA genes are present in the genome. The thermophilic cyanobacterium Thermosynechococcus elongatus contains three psbA genes: psbA1, psbA2, and psbA3, and a new c-type heme protein, Tll0287, was found to be expressed in a strain expressing the psbA2 gene only, but the structure and function of Tll0287 are unknown. Here we solved the crystal structure of Tll0287 at a 2.0 Å resolution. The overall structure of Tll0287 was found to be similar to some kinases and sensor proteins with a Per-Arnt-Sim-like domain rather than to other c-type cytochromes. The fifth and sixth axial ligands for the heme were Cys and His, instead of the His/Met or His/His ligand pairs observed for most of the c-type hemes. The redox potential, E½, of Tll0287 was -255 ± 20 mV versus normal hydrogen electrode at pH values above 7.5. Below this pH value, the E½ increased by ≈57 mV/pH unit at 15 °C, suggesting the involvement of a protonatable group with a pKred = 7.2 ± 0.3. Possible functions of Tll0287 as a redox sensor under microaerobic conditions or a cytochrome subunit of an H2S-oxidizing system are discussed in view of the environmental conditions in which psbA2 is expressed, as well as phylogenetic analysis, structural, and sequence homologies.
キーワード
D1 protein
His-Cys heme axial coordination
PAS domain
PAS-like domain
Tll0287
X-ray crystallography
cytochrome
heme
photosynthesis
photosystem II
発行日
2017-06
出版物タイトル
Journal of Biological Chemistry
292巻
23号
出版者
American Society for Biochemistry and Molecular Biology
開始ページ
9599
終了ページ
9612
ISSN
0021-9258
NCID
AA00251083
資料タイプ
学術雑誌論文
言語
English
OAI-PMH Set
岡山大学
著作権者
https://creativecommons.org/licenses/by-nc-nd/4.0/deed.ja
論文のバージョン
publisher
PubMed ID
DOI
Web of Sience KeyUT
関連URL
isVersionOf https://doi.org/10.1074/jbc.M116.746263