6KAF

C2S2M2N2-type PSII-LHCII

This is a non-PDB format compatible entry.

Summary for 6KAF

• Entry DOI: 10.2210/pdb6kaf/pdb
• EMDB information: 9957
• Descriptor: Chlorophyll a-b binding protein CP29, Photosystem II reaction center protein M, Oxygen-evolving enhancer protein 1 of photosystem II, ... (37 entities in total)
• Functional Keywords: photosystem ii, c2s2m2n2-type psii-lhcii, photosynthesis
• Biological source: Chlamydomonas reinhardtii; More
• Total number of polymer chains: 58
• Total formula weight: 1662088.14

Authors

Chang, S.H.,Shen, L.L.,Huang, Z.H.,Wang, W.D.,Han, G.Y.,Shen, J.R.,Zhang, X. (deposition date: 2019-06-22, release date: 2019-10-23, Last modification date: 2019-11-20)

Primary citation

Shen, L.,Huang, Z.,Chang, S.,Wang, W.,Wang, J.,Kuang, T.,Han, G.,Shen, J.R.,Zhang, X.
Structure of a C2S2M2N2-type PSII-LHCII supercomplex from the green algaChlamydomonas reinhardtii.
Proc.Natl.Acad.Sci.USA, 116:21246-21255, 2019

PubMed Abstract: Photosystem II (PSII) in the thylakoid membranes of plants, algae, and cyanobacteria catalyzes light-induced oxidation of water by which light energy is converted to chemical energy and molecular oxygen is produced. In higher plants and most eukaryotic algae, the PSII core is surrounded by variable numbers of light-harvesting antenna complex II (LHCII), forming a PSII-LHCII supercomplex. In order to harvest energy efficiently at low-light-intensity conditions under water, a complete PSII-LHCII supercomplex (CSMN) of the green alga (Cr) contains more antenna subunits and pigments than the dominant PSII-LHCII supercomplex (CSM) of plants. The detailed structure and energy transfer pathway of the Cr-PSII-LHCII remain unknown. Here we report a cryoelectron microscopy structure of a complete, CSMN-type PSII-LHCII supercomplex from at 3.37-Å resolution. The results show that the Cr-CSMN supercomplex is organized as a dimer, with 3 LHCII trimers, 1 CP26, and 1 CP29 peripheral antenna subunits surrounding each PSII core. The N-LHCII trimer partially occupies the position of CP24, which is present in the higher-plant PSII-LHCII but absent in the green alga. The M trimer is rotated relative to the corresponding M trimer in plant PSII-LHCII. In addition, some unique features were found in the green algal PSII core. The arrangement of a huge number of pigments allowed us to deduce possible energy transfer pathways from the peripheral antennae to the PSII core.

PubMed: 31570614
DOI: 10.1073/pnas.1912462116

Experimental method

ELECTRON MICROSCOPY (3.73 Å)