Structural Basis for Allosteric Regulation in the Major Antenna Trimer of Photosystem II
Structural Basis for Allosteric Regulation in the Major Antenna Trimer of Photosystem II
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DOI：
10.1021/acs.jpcb.9b09767
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发表时间：
2019-11-14
影响因子：
3.3
通讯作者：
Kleinekathoefer, Ulrich
中科院分区：
文献类型：
--
作者：
Daskalakis, Vangelis;Maity, Sayan;Kleinekathoefer, Ulrich
蛋白质功能的变构调节在许多生命维持过程中证明是重要的。在植物光合作用中，LHCII，光系统II的主要天线复合体，在光捕获和光保护模式之间进行微妙的切换。这种开关是由跨类囊体膜的pH梯度（Δ pH）放大触发的。使用分子模拟和量子计算，我们表明，三角洲pH值可以调整光捕获电位的天线通过变构调节的激子耦合叶绿素类胡萝卜素对。为此，我们提出了LHCII激发态寿命是如何耦合到环境条件。与实验结果一致，我们的理论模型提供了重要的证据，对阐明光保护开关的高等植物在全原子分辨率。
The allosteric regulation of protein function proves important in many life-sustaining processes. In plant photosynthesis, LHCII, the major antenna complex of Photosystem II, employs a delicate switch between light harvesting and photoprotective modes. The switch is triggered by an enlarged pH gradient (Delta pH) across the thylakoid membranes. Using molecular simulations and quantum calculations, we show that Delta pH can tune the light-harvesting potential of the antenna via allosteric regulation of the excitonic coupling in chlorophyll-carotenoid pairs. To this end, we propose how the LHCII excited state lifetime is coupled to the environmental conditions. In line with experimental findings, our theoretical model provides crucial evidence toward the elucidation of the photoprotective switch of higher plants at an all-atom resolution.