6YP7

PSII-LHCII C2S2 supercomplex from Pisum sativum grown in high light conditions

Summary for 6YP7

• Entry DOI: 10.2210/pdb6yp7/pdb
• EMDB information: 10865 10866 10867 10868 10887
• Descriptor: Chlorophyll a-b binding protein 8, chloroplastic, Photosystem II reaction center protein J, Photosystem II reaction center protein K, ... (37 entities in total)
• Functional Keywords: cryo-em, photosystem ii, high light, photosynthesis
• Biological source: Pisum sativum (Pea); More
• Total number of polymer chains: 44
• Total formula weight: 1027857.12

Authors

Grinzato, A.,Albanese, P.,Zanotti, G.,Pagliano, C. (deposition date: 2020-04-15, release date: 2020-11-25, Last modification date: 2025-10-01)

Primary citation

Grinzato, A.,Albanese, P.,Marotta, R.,Swuec, P.,Saracco, G.,Bolognesi, M.,Zanotti, G.,Pagliano, C.
High-Light versus Low-Light: Effects on Paired Photosystem II Supercomplex Structural Rearrangement in Pea Plants.
Int J Mol Sci, 21:-, 2020

PubMed Abstract: In plant thylakoid membranes Photosystem II (PSII) associates with a variable number of antenna proteins (LHCII) to form different types of supercomplexes (PSII-LHCII), whose organization is dynamically adjusted in response to light cues, with the CS more abundant in high-light and the CSM in low-light. Paired PSII-LHCII supercomplexes interacting at their stromal surface from adjacent thylakoid membranes were previously suggested to mediate stacking. Here, we present the cryo-electron microscopy maps of paired CS and CSM supercomplexes isolated from pea plants grown in high-light and low-light, respectively. These maps show a different rotational offset between the two supercomplexes in the pair, responsible for modifying their reciprocal interaction and energetic connectivity. This evidence reveals a different way by which paired PSII-LHCII supercomplexes can mediate stacking at diverse irradiances. Electrostatic stromal interactions between LHCII trimers almost completely overlapping in the paired CS can be the main determinant by which PSII-LHCII supercomplexes mediate stacking in plants grown in high-light, whereas the mutual interaction of stromal N-terminal loops of two facing Lhcb4 subunits in the paired CSM can fulfil this task in plants grown in low-light. The high-light induced accumulation of the Lhcb4.3 protein in PSII-LHCII supercomplexes has been previously reported. Our cryo-electron microscopy map at 3.8 Å resolution of the CS supercomplex isolated from plants grown in high-light suggests the presence of the Lhcb4.3 protein revealing peculiar structural features of this high-light-specific antenna important for photoprotection.

PubMed: 33207833
DOI: 10.3390/ijms21228643

Experimental method

ELECTRON MICROSCOPY (3.8 Å)