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-Structure paper
タイトル | A unique photosystem I reaction center from a chlorophyll d-containing cyanobacterium Acaryochloris marina. |
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ジャーナル・号・ページ | J Integr Plant Biol, Vol. 63, Issue 10, Page 1740-1752, Year 2021 |
掲載日 | 2021年6月24日 |
著者 | Caihuang Xu / Qingjun Zhu / Jing-Hua Chen / Liangliang Shen / Xiaohan Yi / Zihui Huang / Wenda Wang / Min Chen / Tingyun Kuang / Jian-Ren Shen / Xing Zhang / Guangye Han / |
PubMed 要旨 | Photosystem I (PSI) is a large protein supercomplex that catalyzes the light-dependent oxidation of plastocyanin (or cytochrome c ) and the reduction of ferredoxin. This catalytic reaction is ...Photosystem I (PSI) is a large protein supercomplex that catalyzes the light-dependent oxidation of plastocyanin (or cytochrome c ) and the reduction of ferredoxin. This catalytic reaction is realized by a transmembrane electron transfer chain consisting of primary electron donor (a special chlorophyll (Chl) pair) and electron acceptors A , A , and three Fe S clusters, F , F , and F . Here we report the PSI structure from a Chl d-dominated cyanobacterium Acaryochloris marina at 3.3 Å resolution obtained by single-particle cryo-electron microscopy. The A. marina PSI exists as a trimer with three identical monomers. Surprisingly, the structure reveals a unique composition of electron transfer chain in which the primary electron acceptor A is composed of two pheophytin a rather than Chl a found in any other well-known PSI structures. A novel subunit Psa27 is observed in the A. marina PSI structure. In addition, 77 Chls, 13 α-carotenes, two phylloquinones, three Fe-S clusters, two phosphatidyl glycerols, and one monogalactosyl-diglyceride were identified in each PSI monomer. Our results provide a structural basis for deciphering the mechanism of photosynthesis in a PSI complex with Chl d as the dominating pigments and absorbing far-red light. |
リンク | J Integr Plant Biol / PubMed:34002536 |
手法 | EM (単粒子) |
解像度 | 3.3 Å |
構造データ | EMDB-30882, PDB-7dwq: |
化合物 | ChemComp-CL7: ChemComp-PQN: ChemComp-SF4: ChemComp-LHG: ChemComp-G9R: ChemComp-PHO: ChemComp-8CT: ChemComp-LMG: |
由来 |
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キーワード | PHOTOSYNTHESIS / Photosystem I / reaction center / cryo-EM / cyanobacteria |