Figure 3.

Peculiar features of proteins and chlorophylls of the C₂S₂ supercomplex isolated from plants grown in high-light. (A) Cryo-EM density map of the C₂S₂-H at 3.8 Å viewed from the lumenal side, normal to the membrane plane, and assigned subunits of the PSII dimer in cyan, LHCII-S trimer in green, Lhcb4 in red and Lhcb5 in orange. (B) Structural superposition of the C-terminal region of Lhcb4 (red) and Lhcb4 from PDB: 5XNL (chain R, purple) [22]. (C) Overview of all chlorophylls a (green) and b (blue) in the supercomplex shown from the lumenal side. (D) Representation of Lhcb4 and Lhcb5 with chlorophyll a (green) and chlorophyll b (blue) molecules. In panel (D), chlorophylls present in the pea C₂S₂ supercomplex from PDB: 5XNL (chain R for Lhcb4 and chain S for Lhcb5) [22] and missing in the C₂S₂-H are highlighted in red, the top view (on the left) and side view (on the right) of proteins are along the membrane plane.