8AM5

RCII/PSI complex, class 3

Summary for 8AM5

• Entry DOI: 10.2210/pdb8am5/pdb
• EMDB information: 15522
• Descriptor: Photosystem II protein D1 2, Photosystem I reaction center subunit II, Photosystem I reaction center subunit IV, ... (32 entities in total)
• Functional Keywords: photosystem, assembly factor, membrane protein, photosynthesis
• Biological source: Synechocystis sp. PCC 6803; More
• Total number of polymer chains: 17
• Total formula weight: 501412.63

Authors

Zhao, Z.,Vercellino, I.,Knoppova, J.,Sobotka, R.,Murray, J.W.,Nixon, P.J.,Sazanov, L.A.,Komenda, J. (deposition date: 2022-08-02, release date: 2023-08-16, Last modification date: 2024-10-09)

Primary citation

Zhao, Z.,Vercellino, I.,Knoppova, J.,Sobotka, R.,Murray, J.W.,Nixon, P.J.,Sazanov, L.A.,Komenda, J.
The Ycf48 accessory factor occupies the site of the oxygen-evolving manganese cluster during photosystem II biogenesis.
Nat Commun, 14:4681-4681, 2023

PubMed Abstract: Robust oxygenic photosynthesis requires a suite of accessory factors to ensure efficient assembly and repair of the oxygen-evolving photosystem two (PSII) complex. The highly conserved Ycf48 assembly factor binds to the newly synthesized D1 reaction center polypeptide and promotes the initial steps of PSII assembly, but its binding site is unclear. Here we use cryo-electron microscopy to determine the structure of a cyanobacterial PSII D1/D2 reaction center assembly complex with Ycf48 attached. Ycf48, a 7-bladed beta propeller, binds to the amino-acid residues of D1 that ultimately ligate the water-oxidising MnCaO cluster, thereby preventing the premature binding of Mn and Ca ions and protecting the site from damage. Interactions with D2 help explain how Ycf48 promotes assembly of the D1/D2 complex. Overall, our work provides valuable insights into the early stages of PSII assembly and the structural changes that create the binding site for the MnCaO cluster.

PubMed: 37542031
DOI: 10.1038/s41467-023-40388-6

Experimental method

ELECTRON MICROSCOPY (3.1 Å)