6JO6

Structure of the green algal photosystem I supercomplex with light-harvesting complex I

Summary for 6JO6

• Entry DOI: 10.2210/pdb6jo6/pdb
• EMDB information: 9854
• Descriptor: Photosystem I P700 chlorophyll a apoprotein A1, Photosystem I reaction center subunit psaK, chloroplastic, Photosystem I reaction center subunit XI, ... (28 entities in total)
• Functional Keywords: photosystem membrane protein, photosynthesis
• Biological source: Chlamydomonas reinhardtii (Chlamydomonas smithii); More
• Total number of polymer chains: 19
• Total formula weight: 696899.02

Authors

Suga, M.,Miyazaki, N.,Takahashi, Y. (deposition date: 2019-03-20, release date: 2019-06-19, Last modification date: 2025-06-25)

Primary citation

Suga, M.,Ozawa, S.I.,Yoshida-Motomura, K.,Akita, F.,Miyazaki, N.,Takahashi, Y.
Structure of the green algal photosystem I supercomplex with a decameric light-harvesting complex I.
Nat.Plants, 5:626-636, 2019

PubMed Abstract: In plants and green algae, the core of photosystem I (PSI) is surrounded by a peripheral antenna system consisting of light-harvesting complex I (LHCI). Here we report the cryo-electron microscopic structure of the PSI-LHCI supercomplex from the green alga Chlamydomonas reinhardtii. The structure reveals that eight Lhca proteins form two tetrameric LHCI belts attached to the PsaF side while the other two Lhca proteins form an additional Lhca2/Lhca9 heterodimer attached to the opposite side. The spatial arrangement of light-harvesting pigments reveals that Chlorophylls b are more abundant in the outer LHCI belt than in the inner LHCI belt and are absent from the core, thereby providing the downhill energy transfer pathways to the PSI core. PSI-LHCI is complexed with a plastocyanin on the patch of lysine residues of PsaF at the luminal side. The assembly provides a structural basis for understanding the mechanism of light-harvesting, excitation energy transfer of the PSI-LHCI supercomplex and electron transfer with plastocyanin.

PubMed: 31182847
DOI: 10.1038/s41477-019-0438-4

Experimental method

ELECTRON MICROSCOPY (2.9 Å)