Structures of the Cyanobacterial Phycobilisome
Structures of the Cyanobacterial Phycobilisome
Abstract The phycobilisome is an elaborate antenna that is responsible for light-harvesting in cyanobacteria and red-algae. This large macromolecular complex captures incident sunlight and transfers the energy via a network of pigment molecules called bilins to the photosynthetic reaction centers. The phycobilisome of the model organism Synechocystis PCC 6803 consists of a core to which six rods are attached but its detailed molecular architecture and regulation in response to environmental conditions is not well understood. Here we present cryo-electron microscopy structures of the 6.2 MDa phycobilisome from Synechocystis PCC 6803 resolved at 2.1 ? (rods) to 2.7 ? (core), revealing three distinct conformations, two previously unknown. We found that two of the rods are mobile and can switch conformation within the complex, revealing a layer of regulation not described previously. In addition, we found a novel linker protein in the structure, that may represent a long-sought subunit that tethers the phycobilisome to the thylakoid membrane. Finally, we show how excitation energy is transferred within the phycobilisome and correlate our structures with known spectroscopic properties. Together, our results provide detailed insights into the biophysical underpinnings of cyanobacterial light harvesting and lay the foundation for bioengineering of future phycobilisome variants and artificial light harvesting systems.
Pol¨avka Tom¨￠?、Sauer Paul V.、Kirst Henning、Kerfeld Cheryl A.、Greber Basil J.、Nogales Eva、Sutter Markus、Bina David、Dominguez-Martin Maria Agustina
Faculty of Science, University of South BohemiaQB3 Institute, University of California||Howard Hughes Medical Institute, University of CaliforniaEnvironmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory||Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National LaboratoryEnvironmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory||Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory||MSU-DOE Plant Research Laboratory, Michigan State University||Department of Biochemistry and Molecular Biology, Michigan State UniversityQB3 Institute, University of California||Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory||Division of Structural Biology, Institute of Cancer ResearchQB3 Institute, University of California||Howard Hughes Medical Institute, University of California||Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory||Department of Molecular and Cellular Biology, University of CaliforniaEnvironmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory||Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory||MSU-DOE Plant Research Laboratory, Michigan State UniversityFaculty of Science, University of South Bohemia||Biology Centre of the Czech Academy of SciencesEnvironmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory||Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory||MSU-DOE Plant Research Laboratory, Michigan State University
生物物理学生物化学分子生物学
Pol¨avka Tom¨￠?,Sauer Paul V.,Kirst Henning,Kerfeld Cheryl A.,Greber Basil J.,Nogales Eva,Sutter Markus,Bina David,Dominguez-Martin Maria Agustina.Structures of the Cyanobacterial Phycobilisome[EB/OL].(2025-03-28)[2025-06-27].https://www.biorxiv.org/content/10.1101/2021.11.15.468712.点此复制
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