title: Structure of spinach photosystem II-LHCII supercomplex at 3.2 Å resolution.
abstract: During photosynthesis, the plant photosystem II core complex receives excitation energy from the peripheral light-harvesting complex II (LHCII). The pathways along which excitation energy is transferred between them, and their assembly mechanisms, remain to be deciphered through high-resolution structural studies. Here we report the structure of a 1.1-megadalton spinach photosystem II-LHCII supercomplex solved at 3.2 Å resolution through single-particle cryo-electron microscopy. The structure reveals a homodimeric supramolecular system in which each monomer contains 25 protein subunits, 105 chlorophylls, 28 carotenoids and other cofactors. Three extrinsic subunits (PsbO, PsbP and PsbQ), which are essential for optimal oxygen-evolving activity of photosystem II, form a triangular crown that shields the Mn4CaO5-binding domains of CP43 and D1. One major trimeric and two minor monomeric LHCIIs associate with each core-complex monomer, and the antenna-core interactions are reinforced by three small intrinsic subunits (PsbW, PsbH and PsbZ). By analysing the closely connected interfacial chlorophylls, we have obtained detailed insights into the energy-transfer pathways between the antenna and core complexes.
authors.affiliation: National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xuepeng
authors.initials: X
authors.lastname: Wei
authors.affiliation: National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Su
authors.affiliation: National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Cao
authors.affiliation: National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xiuying
authors.initials: X
authors.lastname: Liu
authors.affiliation: National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Wenrui
authors.initials: W
authors.lastname: Chang
authors.affiliation: National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.affiliation: National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xinzheng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Liu
mesh_terms: D002338:Carotenoids / Q000737:chemistry; D002734:Chlorophyll / Q000737:chemistry; D020285:Cryoelectron Microscopy; D004579:Electron Transport; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry* / Q000648:ultrastructure*; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000648:ultrastructure*; D021122:Protein Subunits / Q000737:chemistry; D018724:Spinacia oleracea / Q000737:chemistry*
chemical_list: D045342:Light-Harvesting Protein Complexes; D045332:Photosystem II Protein Complex; D021122:Protein Subunits; D002734:Chlorophyll; D002338:Carotenoids