6IJO

Photosystem I of Chlamydomonas reinhardtii

Summary for 6IJO

• Entry DOI: 10.2210/pdb6ijo/pdb
• EMDB information: 9678 9680
• Descriptor: PsaA, PsaJ, PsaK, ... (33 entities in total)
• Functional Keywords: photosystem, antenna, supercomplex, green alga, photosynthesis
• Biological source: Chlamydomonas reinhardtii; More
• Total number of polymer chains: 23
• Total formula weight: 892585.23

Authors

Pan, X.,Ma, J.,Su, X.,Liu, Z.,Zhang, X.,Li, M. (deposition date: 2018-10-10, release date: 2019-03-20, Last modification date: 2019-05-01)

Primary citation

Su, X.,Ma, J.,Pan, X.,Zhao, X.,Chang, W.,Liu, Z.,Zhang, X.,Li, M.
Antenna arrangement and energy transfer pathways of a green algal photosystem-I-LHCI supercomplex.
Nat Plants, 5:273-281, 2019

PubMed Abstract: During oxygenic photosynthesis, photosystems I and II (PSI and PSII) are essential for light-driven electron transport. Excitation energy transfer in PSI occurs extremely quickly, making it an efficient energy converter. In the alga Chlamydomonas reinhardtii (Cr), multiple units of light-harvesting complex I (LHCI) bind to the PSI core and function as peripheral antennae, forming a PSI-LHCI supercomplex. CrPSI-LHCI shows significantly larger antennae compared with plant PSI-LHCI while maintaining highly efficient energy transfer from LHCI to PSI. Here, we report structures of CrPSI-LHCI, solved by cryo-electron microscopy, revealing that up to ten LHCIs are associated with the PSI core. The structures provide detailed information about antenna organization and pigment arrangement within the supercomplexes. Highly populated and closely associated chlorophylls in the antennae explain the high efficiency of light harvesting and excitation energy transfer in CrPSI-LHCI.

PubMed: 30850819
DOI: 10.1038/s41477-019-0380-5

Experimental method

ELECTRON MICROSCOPY (3.3 Å)