TY - JOUR
T1 - Structural basis for energy transfer in a huge diatom PSI-FCPI supercomplex
AU - Xu, Caizhe
AU - Pi, Xiong
AU - Huang, Yawen
AU - Han, Guangye
AU - Chen, Xiaobo
AU - Qin, Xiaochun
AU - Huang, Guoqiang
AU - Zhao, Songhao
AU - Yang, Yanyan
AU - Kuang, Tingyun
AU - Wang, Wenda
AU - Sui, Sen Fang
AU - Shen, Jian Ren
N1 - Funding Information:
We thank J. Lei and the staff at the Tsinghua University Branch of China National Center for Protein Sciences (Beijing) for providing facility support on the Cryo-EM and High-Performance Computation platforms. This work was supported by the National Key R&D Program of China (2017YFA0503700, 2017YFA0504600, 2019YFA0906300, and 2016YFA0501101); the National Natural Science Foundation of China (31970260, 31600191, 31861143048, and 31670745); a Strategic Priority Research Program of CAS (XDB17000000), a CAS Key Research Program for Frontier Science (QYZDY-SSW-SMC003), and Youth Innovation Promotion Association of CAS (2020081).
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Diatom is an important group of marine algae and contributes to around 20% of the global photosynthetic carbon fixation. Photosystem I (PSI) of diatoms is associated with a large number of fucoxanthin-chlorophyll a/c proteins (FCPIs). We report the structure of PSI-FCPI from a diatom Chaetoceros gracilis at 2.38 Å resolution by single-particle cryo-electron microscopy. PSI-FCPI is a monomeric supercomplex consisting of 12 core and 24 antenna subunits (FCPIs), and 326 chlorophylls a, 34 chlorophylls c, 102 fucoxanthins, 35 diadinoxanthins, 18 β-carotenes and some electron transfer cofactors. Two subunits designated PsaR and PsaS were found in the core, whereas several subunits were lost. The large number of pigments constitute a unique and huge network ensuring efficient energy harvesting, transfer and dissipation. These results provide a firm structural basis for unraveling the mechanisms of light-energy harvesting, transfer and quenching in the diatom PSI-FCPI, and also important clues to evolutionary changes of PSI-LHCI.
AB - Diatom is an important group of marine algae and contributes to around 20% of the global photosynthetic carbon fixation. Photosystem I (PSI) of diatoms is associated with a large number of fucoxanthin-chlorophyll a/c proteins (FCPIs). We report the structure of PSI-FCPI from a diatom Chaetoceros gracilis at 2.38 Å resolution by single-particle cryo-electron microscopy. PSI-FCPI is a monomeric supercomplex consisting of 12 core and 24 antenna subunits (FCPIs), and 326 chlorophylls a, 34 chlorophylls c, 102 fucoxanthins, 35 diadinoxanthins, 18 β-carotenes and some electron transfer cofactors. Two subunits designated PsaR and PsaS were found in the core, whereas several subunits were lost. The large number of pigments constitute a unique and huge network ensuring efficient energy harvesting, transfer and dissipation. These results provide a firm structural basis for unraveling the mechanisms of light-energy harvesting, transfer and quenching in the diatom PSI-FCPI, and also important clues to evolutionary changes of PSI-LHCI.
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U2 - 10.1038/s41467-020-18867-x
DO - 10.1038/s41467-020-18867-x
M3 - Article
C2 - 33033236
AN - SCOPUS:85092270656
SN - 2041-1723
VL - 11
JO - Nature communications
JF - Nature communications
IS - 1
M1 - 5081
ER -
