7FIX
Cryo-EM structure of cyanobacterial photosystem I in the presence of ferredoxin and cytochrome c6
This is a non-PDB format compatible entry.
Summary for 7FIX
| Entry DOI | 10.2210/pdb7fix/pdb |
| EMDB information | 31605 |
| Descriptor | Photosystem I P700 chlorophyll a apoprotein A1, Photosystem I reaction center subunit XI, Photosystem I reaction center subunit XII, ... (24 entities in total) |
| Functional Keywords | photosystem i, ferredoxin, cytochrome c6, photosynthesis |
| Biological source | Thermosynechococcus vestitus BP-1 More |
| Total number of polymer chains | 39 |
| Total formula weight | 1125795.17 |
| Authors | Li, J.,Kurisu, G. (deposition date: 2021-08-01, release date: 2022-09-21, Last modification date: 2022-09-28) |
| Primary citation | Li, J.,Hamaoka, N.,Makino, F.,Kawamoto, A.,Lin, Y.,Rogner, M.,Nowaczyk, M.M.,Lee, Y.H.,Namba, K.,Gerle, C.,Kurisu, G. Structure of cyanobacterial photosystem I complexed with ferredoxin at 1.97 angstrom resolution. Commun Biol, 5:951-951, 2022 Cited by PubMed Abstract: Photosystem I (PSI) is a light driven electron pump transferring electrons from Cytochrome c (Cyt c) to Ferredoxin (Fd). An understanding of this electron transfer process is hampered by a paucity of structural detail concerning PSI:Fd interface and the possible binding sites of Cyt c. Here we describe the high resolution cryo-EM structure of Thermosynechococcus elongatus BP-1 PSI in complex with Fd and a loosely bound Cyt c. Side chain interactions at the PSI:Fd interface including bridging water molecules are visualized in detail. The structure explains the properties of mutants of PsaE and PsaC that affect kinetics of Fd binding and suggests a molecular switch for the dissociation of Fd upon reduction. Calorimetry-based thermodynamic analyses confirms a single binding site for Fd and demonstrates that PSI:Fd complexation is purely driven by entropy. A possible reaction cycle for the efficient transfer of electrons from Cyt c to Fd via PSI is proposed. PubMed: 36097054DOI: 10.1038/s42003-022-03926-4 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (1.97 Å) |
Structure validation
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