7R3K
Chlamydomonas reinhardtii TSP9 mutant small Photosystem I complex
Summary for 7R3K
Entry DOI | 10.2210/pdb7r3k/pdb |
EMDB information | 14248 |
Descriptor | Photosystem I P700 chlorophyll a apoprotein A1, Photosystem I reaction center subunit psaK, chloroplastic, Chlorophyll a-b binding protein, chloroplastic, ... (39 entities in total) |
Functional Keywords | photosystem i, complex, green algae, photosynthesis |
Biological source | Chlamydomonas reinhardtii More |
Total number of polymer chains | 18 |
Total formula weight | 735225.13 |
Authors | Klaiman, D.,Schwartz, T.,Nelson, N. (deposition date: 2022-02-07, release date: 2023-02-22, Last modification date: 2023-04-12) |
Primary citation | Schwartz, T.,Fadeeva, M.,Klaiman, D.,Nelson, N. Structure of Photosystem I Supercomplex Isolated from a Chlamydomonas reinhardtii Cytochrome b6f Temperature-Sensitive Mutant. Biomolecules, 13:-, 2023 Cited by PubMed Abstract: The unicellular green alga, , has been widely used as a model system to study photosynthesis. Its possibility to generate and analyze specific mutants has made it an excellent tool for mechanistic and biogenesis studies. Using negative selection of ultraviolet (UV) irradiation-mutated cells, we isolated a mutant (TSP9) with a single amino acid mutation in the Rieske protein of the cytochrome b6f complex. The W143R mutation in the petC gene resulted in total loss of cytochrome b6f complex function at the non-permissive temperature of 37 °C and recovery at the permissive temperature of 25 °C. We then isolated photosystem I (PSI) and photosystem II (PSII) supercomplexes from cells grown at the non-permissive temperature and determined the PSI structure with high-resolution cryogenic electron microscopy. There were several structural alterations compared with the structures obtained from wild-type cells. Our structural data suggest that the mutant responded by excluding the Lhca2, Lhca9, PsaL, and PsaH subunits. This structural alteration prevents state two transition, where LHCII migrates from PSII to bind to the PSI complex. We propose this as a possible response mechanism triggered by the TSP9 phenotype at the non-permissive temperature. PubMed: 36979472DOI: 10.3390/biom13030537 PDB entries with the same primary citation |
Experimental method | ELECTRON MICROSCOPY (2.52 Å) |
Structure validation
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