6TCL

Photosystem I tetramer

This is a non-PDB format compatible entry.

Summary for 6TCL

• Entry DOI: 10.2210/pdb6tcl/pdb
• EMDB information: 10461
• Descriptor: Photosystem I P700 chlorophyll a apoprotein A1, Photosystem I reaction center subunit XI, Photosystem I reaction center subunit XII, ... (28 entities in total)
• Functional Keywords: photosynthesis, tetramer, anabaena, psi
• Biological source: Nostoc sp. PCC 7120; More
• Total number of polymer chains: 48
• Total formula weight: 1478636.48

Authors

Chen, M.,Perez-Boerema, A.,Li, S.,Amunts, A. (deposition date: 2019-11-06, release date: 2020-02-19, Last modification date: 2024-05-22)

Primary citation

Chen, M.,Perez-Boerema, A.,Zhang, L.,Li, Y.,Yang, M.,Li, S.,Amunts, A.
Distinct structural modulation of photosystem I and lipid environment stabilizes its tetrameric assembly.
Nat.Plants, 6:314-320, 2020

PubMed Abstract: Photosystem I (PSI) is able to form different oligomeric states across various species. To reveal the structural basis for PSI dimerization and tetramerization, we structurally investigated PSI from the cyanobacterium Anabaena. This revealed a disrupted trimerization domain due to lack of the terminal residues of PsaL in the lumen, which resulted in PSI dimers with loose connections between monomers and weaker energy-coupled chlorophylls than in the trimer. At the dimer surface, specific phospholipids, cofactors and interactions in combination facilitated recruitment of another dimer to form a tetramer. Taken together, the relaxed luminal connections and lipid specificity at the dimer interface account for membrane curvature. PSI tetramer assembly appears to increase the surface area of the thylakoid membrane, which would contribute to PSI crowding.

PubMed: 32170279
DOI: 10.1038/s41477-020-0610-x

Experimental method

ELECTRON MICROSCOPY (3.2 Å)