中国科学院植物研究所沈建仁、匡廷云课题组和清华大学隋森芳课题组，通过合作首次解析了硅藻光系统II-捕光天线超级复合体的原子水平三维结构。相关论文于2019年8月2日发表在国际著名学术期刊《科学》上。

研究人员报道了来自一种中心纲硅藻（Chaetoceros gracilis）的光系统II-岩藻黄素和叶绿素a/c结合蛋白（PSII-FCPII）超级复合体的冷冻电镜结构。这个超级复合体由两个PSII-FCPII单体组成，每个单体具有两个四聚的以及三个单聚的FCPII围绕在PSII核心周围，而核心则在腔体表面具有5个外周放氧蛋白。这一结构揭示了硅藻中巨大色素网络的排布如何有助于高效的光能量吸收、转移以及耗散过程。

据了解，硅藻在全球原初生产力和碳的生物地球化学循环中发挥着重要作用，这部分归功于其光合器能够适应光线强度的快速变化。

附：英文原文

Title: The pigment-protein network of a diatom photosystem II–light-harvesting antenna supercomplex

Author: Xiong Pi, Songhao Zhao, Wenda Wang, Desheng Liu, Caizhe Xu, Guangye Han, Tingyun Kuang, Sen-Fang Sui, Jian-Ren Shen

Issue&Volume: Vol 365 Issue 6452

Abstract: Diatoms play important roles in global primary productivity and biogeochemical cycling of carbon, in part owing to the ability of their photosynthetic apparatus to adapt to rapidly changing light intensity. We report a cryo–electron microscopy structure of the photosystem II (PSII)–fucoxanthin (Fx) chlorophyll (Chl) a/c binding protein (FCPII) supercomplex from the centric diatom Chaetoceros gracilis. The supercomplex comprises two protomers, each with two tetrameric and three monomeric FCPIIs around a PSII core that contains five extrinsic oxygen-evolving proteins at the lumenal surface. The structure reveals the arrangement of a huge pigment network that contributes to efficient light energy harvesting, transfer, and dissipation processes in the diatoms.

DOI: 10.1126/science.aax4406

Source: https://science.sciencemag.org/content/365/6452/eaax4406