Structure and function of a huge photosystem I-fucoxanthin chlorophyll supercomplex from a coccolithophore

• 成果类型: Article
• 署名作者: Shen, Lili; Ren, Fei; Wang, Yin-Chu; Li, Zhenhua; Zheng, Mengyuan; Li, Xiaoyi; Fan, Wenzheng; Yang, Yanyan; Sang, Min; Liu, Cheng; Han, Guangye; Qin, Song; Fan, Jianhua; Tian, Lijin; Kuang, Tingyun; Shen, Jian-Ren; Wang, Wenda
• 署名单位: Chinese Academy of Sciences; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Yantai Institute of Coastal Zone Research, CAS; Shihezi University; Okayama University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12131
• DOI: 10.1126/science.adv2132
• 发表日期: 2025-09-11
• 关键词: emiliania-huxleyi prymnesiophyceae; light-harvesting complex; energy-transfer pathways; excitation-energy; chlamydomonas-reinhardtii; psi-lhci; phytoplankton; protein; MODEL; calcification

摘要

Photosystem I (PSI) is a pigment-protein complex, which converts light energy into chemical energy in photosynthesis. Among photosynthetic organisms, PSI-LHC (light-harvesting complex) structures exhibit substantial differences in their sizes, reflecting adaptation to different light environments. Here we report the structure of a PSI-fucoxanthin chlorophyll a/c binding protein (FCPI) supercomplex from the coccolithophore Emiliania huxleyi (Eh) at 2.79-angstrom resolution by cryo-electron microscopy, which showed a huge Eh-PSI-FCPI supercomplex containing 38 peripheral Eh-FCPI antennae and a linker protein (EhLP) in addition to the PSI core. A network of 819 pigments was found in Eh-PSI-FCPI, which functions to capture and transfer light energy with 95% quantum efficiency. This elucidates how its modular Eh-FCPI arrangement contributes to the expansion of PSI cross section and efficient light harvesting.