8JZF

PSI-AcpPCI supercomplex from Symbiodinium

Summary for 8JZF

• Entry DOI: 10.2210/pdb8jzf/pdb
• EMDB information: 36743
• Descriptor: Chlorophyll a-chlorophyll c-peridinin-protein-complex I-7, acpPCI-7, Photosystem I PsaF, Photosystem I PsaR, ... (37 entities in total)
• Functional Keywords: photosysrem i, photosynthesis, dinoflagellate
• Biological source: Symbiodinium; More
• Total number of polymer chains: 25
• Total formula weight: 793318.36

Authors

Li, X.Y.,Li, Z.H.,Wang, W.D. (deposition date: 2023-07-05, release date: 2024-02-28, Last modification date: 2024-10-23)

Primary citation

Li, X.,Li, Z.,Wang, F.,Zhao, S.,Xu, C.,Mao, Z.,Duan, J.,Feng, Y.,Yang, Y.,Shen, L.,Wang, G.,Yang, Y.,Yu, L.J.,Sang, M.,Han, G.,Wang, X.,Kuang, T.,Shen, J.R.,Wang, W.
Structures and organizations of PSI-AcpPCI supercomplexes from red tidal and coral symbiotic photosynthetic dinoflagellates.
Proc.Natl.Acad.Sci.USA, 121:e2315476121-e2315476121, 2024

PubMed Abstract: 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) /-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 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. Similar modifications are observed in a coral symbiotic dinoflagellate species, where two additional core proteins and fewer AcpPCIs are identified in the PSI-AcpPCI supercomplex. The antenna proteins AcpPCIs in dinoflagellates developed some loops and pigment sites as a result to accommodate the changed PSI core, therefore the structures of PSI-AcpPCI supercomplex of dinoflagellates reveal an unusual protein assembly pattern. A huge pigment network comprising Chls and and various carotenoids is revealed from the structural analysis, which provides the basis for our deeper understanding of the energy transfer and dissipation within the PSI-AcpPCI supercomplex, as well as the evolution of photosynthetic organisms.

PubMed: 38319970
DOI: 10.1073/pnas.2315476121

Experimental method

ELECTRON MICROSCOPY (2.7 Å)