Structural basis for different types of hetero-tetrameric light-harvesting complexes in a diatom PSII-FCPII supercomplex
Nagao, R.; Kato, K.; Kumazawa, M.; Ifuku, K.; Yokono, M.; Suzuki, T.; Dohmae, N.; Akita, F.; Akimoto, S.; Miyazaki, N.; Shen, J.-R. (2022). Structural basis for different types of hetero-tetrameric light-harvesting complexes in a diatom PSII-FCPII supercomplex. Nature Comm. 13: 1764. https://dx.doi.org/10.1038/s41467-022-29294-5
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, more
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| Authors | | Top |
- Nagao, R.
- Kato, K.
- Kumazawa, M.
- Ifuku, K.
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- Yokono, M.
- Suzuki, T.
- Dohmae, N.
- Akita, F.
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- Akimoto, S.
- Miyazaki, N.
- Shen, J.-R.
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| Abstract |
Fucoxanthin chlorophyll (Chl) a/c-binding proteins (FCPs) function as light harvesters in diatoms. The structure of a diatom photosystem II-FCPII (PSII-FCPII) supercomplex have been solved by cryo-electron microscopy (cryo-EM) previously; however, the FCPII subunits that constitute the FCPII tetramers and monomers are not identified individually due to their low resolutions. Here, we report a 2.5 Å resolution structure of the PSII-FCPII supercomplex using cryo-EM. Two types of tetrameric FCPs, S-tetramer, and M-tetramer, are identified as different types of hetero-tetrameric complexes. In addition, three FCP monomers, m1, m2, and m3, are assigned to different gene products of FCP. The present structure also identifies the positions of most Chls c and diadinoxanthins, which form a complicated pigment network. Excitation-energy transfer from FCPII to PSII is revealed by time-resolved fluorescence spectroscopy. These structural and spectroscopic findings provide insights into an assembly model of FCPII and its excitation-energy transfer and quenching processes. |
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