硅藻岩藻黄素-叶绿素 a/c 蛋白——揭秘红系捕光天线复合物

硅藻是海洋中一类重要的红色浮游植物，每年贡献了海洋40%或全球20%左右的原初生产力，在全球碳固定和地球化学循环中扮演重要角色。硅藻能取得如此成功生态位的一个重要因素是其捕光天线为具有出色捕光和光适应能力的岩藻黄素-叶绿素a/c结合蛋白(FCP)。为研究硅藻在水下高效利用蓝绿光、传递和转化太阳能的机理，我们团队与合作者利用晶体学和冷冻电镜技术破解了硅藻FCP捕光天线和光系统超级复合物的结构，揭示了FCP蛋白的独特结构特征和聚合状态，以及与其结合的大量叶绿素a、叶绿素c和岩藻黄素等色素分子的结合细节，为揭秘硅藻光合膜蛋白机器高效运行机理提供坚实的结构基础。

Fucoxanthin chlorophyll a/c-binding proteins in diatoms: Deciphering red lineage of light-harvesting complex

Diatoms are an important group of red phytoplankton in the ocean and contribute about 40% of marine or 20% of the global primary productivity, playing significant roles in global carbon fixation and geochemical cycle. An important factor that contributes to the ecological success of diatoms is their fucoxanthin (Fx) chlorophyll (Chl) a/c-binding proteins (FCPs), which have exceptional capabilities in light harvesting and adaptation. To study efficient blue-green light harvesting, energy transfer and conversion in diatoms under water, our research team collaborated with coworkers and solved a crystal structure of FCP-type light-harvesting complex and a cryo-electron microscopic structure of photosystem II-FCPII supercomplex from diatoms. These two structures reveal unique structural properties and aggregated states of FCP antennae, as well as the details of chlorophylls a, chlorophylls c and fucoxanthin pigments they bound, thus providing the solid basis for deciphering the highly efficient light-energy utilization mechanism of the photosynthetic machinery in diatoms.