Work

Architecture and functional regulation of a plant PSII-LHCII megacomplex

Year: 2024

Type: article

Abstract: Photosystem II (PSII) splits water in oxygenic photosynthesis on Earth. The structure and function of the C 4 S 4 M 2 -type PSII-LHCII (light-harvesting complex II) megacomplexes from the wild-type and PsbR-deletion mutant plants are studied through electron microscopy (EM), structural mass spectrometry, and ultrafast fluorescence spectroscopy [time-resolved fluorescence (TRF)]. The cryo-EM structure of a type I C 4 S 4 M 2 megacomplex demonstrates that the three domains of PsbR bind to the stromal side of D1, D2, and CP43; associate with the single transmembrane helix of the redox active Cyt b 559 ; and stabilize the luminal extrinsic PsbP, respectively. This megacomplex, with PsbR and PsbY centered around the narrow interface between two dimeric PSII cores, provides the supramolecular structural basis that regulates the plastoquinone occupancy in Q B site, excitation energy transfer, and oxygen evolution. PSII-LHCII megacomplexes (types I and II) and LHC aggregation levels in Arabidopsis psbR mutant were also interrogated and compared to wild-type plants through EM and picosecond TRF.

Source: Science Advances

DOI: 10.1126/sciadv.adq9967

Authors: Jianyu Shan, Dariusz M. Niedzwiedzki, Rupal S. Tomar, Zhenfeng Liu, Haijun Liu

Institutions: Chinese Academy of Sciences, Institute of Biophysics, University of Chinese Academy of Sciences, Washington University in St. Louis, Saint Louis University

Language: English

Topic: Photosynthetic Processes and Mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $4,500

Funder: U.S. Department of Energy