7DZ7

State transition supercomplex PSI-LHCI-LHCII from double phosphatase mutant pph1;pbcp of green alga Chlamydomonas reinhardtii

Summary for 7DZ7

• Entry DOI: 10.2210/pdb7dz7/pdb
• EMDB information: 30925
• Descriptor: Photosystem I P700 chlorophyll a apoprotein A1, Photosystem I reaction center subunit IX, Photosystem I reaction center subunit psaK, chloroplastic, ... (38 entities in total)
• Functional Keywords: supercomplex, state transition, green alga, chlamydomonas reinhardtii, photosynthesis
• Biological source: Chlamydomonas reinhardtii (Chlamydomonas smithii); More
• Total number of polymer chains: 29
• Total formula weight: 1132474.73

Authors

Pan, X.W.,Li, A.J.,Liu, Z.F.,Li, M. (deposition date: 2021-01-23, release date: 2021-06-30, Last modification date: 2025-07-02)

Primary citation

Pan, X.,Tokutsu, R.,Li, A.,Takizawa, K.,Song, C.,Murata, K.,Yamasaki, T.,Liu, Z.,Minagawa, J.,Li, M.
Structural basis of LhcbM5-mediated state transitions in green algae.
Nat.Plants, 7:1119-1131, 2021

PubMed Abstract: In green algae and plants, state transitions serve as a short-term light-acclimation process in the regulation of the light-harvesting capacity of photosystems I and II (PSI and PSII, respectively). During the process, a portion of light-harvesting complex II (LHCII) is phosphorylated, dissociated from PSII and binds with PSI to form the supercomplex PSI-LHCI-LHCII. Here, we report high-resolution structures of PSI-LHCI-LHCII from Chlamydomonas reinhardtii, revealing the mechanism of assembly between the PSI-LHCI complex and two phosphorylated LHCII trimers containing all four types of LhcbM protein. Two specific LhcbM isoforms, namely LhcbM1 and LhcbM5, directly interact with the PSI core through their phosphorylated amino terminal regions. Furthermore, biochemical and functional studies on mutant strains lacking either LhcbM1 or LhcbM5 indicate that only LhcbM5 is indispensable in supercomplex formation. The results unravel the specific interactions and potential excitation energy transfer routes between green algal PSI and two phosphorylated LHCIIs.

PubMed: 34239095
DOI: 10.1038/s41477-021-00960-8

Experimental method

ELECTRON MICROSCOPY (2.84 Å)