Structural and quantum chemical basis for OCP-mediated quenching of phycobilisomes.

Autor: Sauer PV; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720, USA.; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA., Cupellini L; Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, I-56124 Pisa, Italy., Sutter M; MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA., Bondanza M; Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, I-56124 Pisa, Italy., Domínguez Martin MA; MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA., Kirst H; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA., Bína D; Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic.; Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic., Koh AF; Thermo Fisher Scientific, Eindhoven, Netherlands., Kotecha A; Thermo Fisher Scientific, Eindhoven, Netherlands., Greber BJ; Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK., Nogales E; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720, USA.; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA.; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.; Department of Molecular and Cellular Biology, University of California, Berkeley, CA 94720, USA., Polívka T, Mennucci B; Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, I-56124 Pisa, Italy., Kerfeld CA; MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.
Jazyk: angličtina
Zdroj: Science advances [Sci Adv] 2024 Apr 05; Vol. 10 (14), pp. eadk7535. Date of Electronic Publication: 2024 Apr 05.
DOI: 10.1126/sciadv.adk7535
Abstrakt: Cyanobacteria use large antenna complexes called phycobilisomes (PBSs) for light harvesting. However, intense light triggers non-photochemical quenching, where the orange carotenoid protein (OCP) binds to PBS, dissipating excess energy as heat. The mechanism of efficiently transferring energy from phycocyanobilins in PBS to canthaxanthin in OCP remains insufficiently understood. Using cryo-electron microscopy, we unveiled the OCP-PBS complex structure at 1.6- to 2.1-angstrom resolution, showcasing its inherent flexibility. Using multiscale quantum chemistry, we disclosed the quenching mechanism. Identifying key protein residues, we clarified how canthaxanthin's transition dipole moment in its lowest-energy dark state becomes large enough for efficient energy transfer from phycocyanobilins. Our energy transfer model offers a detailed understanding of the atomic determinants of light harvesting regulation and antenna architecture in cyanobacteria.
Databáze: MEDLINE