Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, China.
Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, 700-8530 Okayama, Japan.
Science. 2019 Feb 8;363(6427). doi: 10.1126/science.aav0365.
Diatoms are abundant photosynthetic organisms in aquatic environments and contribute 40% of its primary productivity. An important factor that contributes to the success of diatoms is their fucoxanthin chlorophyll a/c-binding proteins (FCPs), which have exceptional light-harvesting and photoprotection capabilities. Here, we report the crystal structure of an FCP from the marine diatom , which reveals the binding of seven chlorophylls (Chls) a, two Chls c, seven fucoxanthins (Fxs), and probably one diadinoxanthin within the protein scaffold. Efficient energy transfer pathways can be found between Chl a and c, and each Fx is surrounded by Chls, enabling the energy transfer and quenching via Fx highly efficient. The structure provides a basis for elucidating the mechanisms of blue-green light harvesting, energy transfer, and dissipation in diatoms.
硅藻是水生环境中丰富的光合生物，贡献了其初级生产力的 40%。硅藻成功的一个重要因素是它们的叶黄素叶绿素 a/c 结合蛋白（FCPs），这种蛋白具有出色的光捕获和光保护能力。在这里，我们报告了一种来自海洋硅藻的 FCP 的晶体结构，揭示了该蛋白结构中结合了七个叶绿素 a（Chl a）、两个叶绿素 c（Chl c）、七个岩藻黄素（Fxs）和可能一个二氢玉米黄质（diadinoxanthin）。在 Chl a 和 c 之间可以发现有效的能量转移途径，并且每个 Fx 都被 Chls 包围，使得通过 Fx 的能量转移和猝灭非常高效。该结构为阐明硅藻中蓝绿光的捕获、能量转移和耗散机制提供了基础。
