Xiaoyi Li, Zhenhua Li, Fangfang Wang, Songhao Zhao, Caizhe Xu, Zhiyuan Mao, Jialin Duan, Yue Feng, Yang Yang, Lili Shen, Guanglei Wang, Yanyan Yang, Long-Jiang Yu, Min Sang, Guangye Han, Xuchu Wang, Tingyun Kuang, Jian-Ren Shen, Wenda Wang
Marine photosynthetic dinoflagellates are a group of successful phytoplankton that can form red tides in the ocean and also symbiosis with corals. These features are closely related to the photosynthetic properties of dinoflagellates. We report here three structures of photosystem I (PSI)-chlorophylls (Chls) a / c -peridinin protein complex (PSI-AcpPCI) from two species of dinoflagellates by single-particle cryoelectron microscopy. The crucial PsaA/B subunits of a red tidal dinoflagellate Amphidinium carterae are remarkably smaller and hence losing over 20 pigment-binding sites, whereas its PsaD/F/I/J/L/M/R subunits are larger and coordinate some additional pigment sites compared to other eukaryotic photosynthetic organisms, which may compensate for the smaller PsaA/B subunits...
February 13, 2024: Proceedings of the National Academy of Sciences of the United States of America