6KAC

Cryo-EM structure of the C2S2-type PSII-LHCII supercomplex from Chlamydomonas reihardtii

Summary for 6KAC

• Entry DOI: 10.2210/pdb6kac/pdb
• EMDB information: 9955
• Descriptor: Photosystem II protein D1, Photosystem II reaction center protein J, Photosystem II reaction center protein K, ... (47 entities in total)
• Functional Keywords: photosystemii, supercomplex, photosynthesis
• Biological source: Chlamydomonas reinhardtii; More
• Total number of polymer chains: 56
• Total formula weight: 1273106.71

Authors

Sheng, X.,Li, A.J.,Song, D.F.,Liu, Z.F. (deposition date: 2019-06-21, release date: 2019-10-23, Last modification date: 2019-12-25)

Primary citation

Sheng, X.,Watanabe, A.,Li, A.,Kim, E.,Song, C.,Murata, K.,Song, D.,Minagawa, J.,Liu, Z.
Structural insight into light harvesting for photosystem II in green algae.
Nat.Plants, 5:1320-1330, 2019

PubMed Abstract: Green algae and plants rely on light-harvesting complex II (LHCII) to collect photon energy for oxygenic photosynthesis. In Chlamydomonas reinhardtii, LHCII molecules associate with photosystem II (PSII) to form various supercomplexes, including the CSML type, which is the largest PSII-LHCII supercomplex in algae and plants that is presently known. Here, we report high-resolution cryo-electron microscopy (cryo-EM) maps and structural models of the CSML and CS supercomplexes from C. reinhardtii. The CS supercomplex contains an LhcbM1-LhcbM2/7-LhcbM3 heterotrimer in the strongly associated LHCII, and the LhcbM1 subunit assembles with CP43 through two interfacial galactolipid molecules. The loosely and moderately associated LHCII trimers interact closely with the minor antenna complex CP29 to form an intricate subcomplex bound to CP47 in the CSML supercomplex. A notable direct pathway is established for energy transfer from the loosely associated LHCII to the PSII reaction centre, as well as several indirect routes. Structure-based computational analysis on the excitation energy transfer within the two supercomplexes provides detailed mechanistic insights into the light-harvesting process in green algae.

PubMed: 31768031
DOI: 10.1038/s41477-019-0543-4

Experimental method

ELECTRON MICROSCOPY (2.7 Å)