Structural and functional insights into the tetrameric photosystem I from heterocyst-forming cyanobacteria
Structural and functional insights into the tetrameric photosystem I from heterocyst-forming cyanobacteria
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从形成异形蓝细菌的四聚体光系统 I 的结构和功能洞察
DOI：
10.1038/s41477-019-0525-6
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发表时间：
2019
期刊：
影响因子：
18
通讯作者：
Gao Ning
中科院分区：
文献类型：
--
作者：
Zheng Lvqin;Li Yanbing;Li Xiying;Zhong Qinglu;Li Ningning;Zhang Kun;Zhang Yuebin;Chu Huiying;Ma Chengying;Li Guohui;Zhao Jindong;Gao Ning
两个大型的蛋白质辅因子复合体，光系统I和光系统II，是类囊体膜光合作用的中心成分。在这里，我们报告了来自形成异胞的蓝藻Anabaenasp的四聚体光系统I复合体的2.37°结构。PCC7120。四个光系统I单体以二聚体的形式组织，形成两个不同的界面，这两个界面主要由特定取向的极性脂类介导，如磺基喹诺酮糖二酰甘油。与嗜热蓝藻的三聚体PSI相比，该结构描述了一个更紧密地连接在单体界面上的叶绿素网络，这可能允许单体之间更有效的能量转移。我们的生理数据还揭示了光系统I齐聚与循环电子流和类囊体膜组织的功能联系。
Two large protein-cofactor complexes, photosystem I and photosystem II, are the central components of photosynthesis in the thylakoid membranes. Here, we report the 2.37-Å structure of a tetrameric photosystem I complex from a heterocyst-forming cyanobacteriumAnabaenasp. PCC 7120. Four photosystem I monomers, organized in a dimer of dimer, form two distinct interfaces that are largely mediated by specifically orientated polar lipids, such as sulfoquinovosyl diacylglycerol. The structure depicts a more closely connected network of chlorophylls across monomer interfaces than those seen in trimeric PSI from thermophilic cyanobacteria, possibly allowing a more efficient energy transfer between monomers. Our physiological data also revealed a functional link of photosystem I oligomerization to cyclic electron flow and thylakoid membrane organization.