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DOI	10.1073/pnas.2021157118
	Cryo-EM structure and kinetics reveal electron transfer by 2D diffusion of cytochrome c in the yeast III-IV respiratory supercomplex
	Moe A.; Trani J.D.; Rubinstein J.L.; Brzezinski P.
发表日期	2021
ISSN	00278424
卷号	118 期号:11
英文摘要	Energy conversion in aerobic organisms involves an electron current from low-potential donors, such as NADH and succinate, to dioxygen through the membrane-bound respiratory chain. Electron transfer is coupled to transmembrane proton transport, which maintains the electrochemical proton gradient used to produce ATP and drive other cellular processes. Electrons are transferred from respiratory complexes III to IV (CIII and CIV) by watersoluble cytochrome (cyt.) c. In Saccharomyces cerevisiae and some other organisms, these complexes assemble into larger CIII2CIV1/2supercomplexes, the functional significance of which has remained enigmatic. In this work, we measured the kinetics of the S. cerevisiae supercomplex cyt. c-mediated QH2:O2oxidoreductase activity under various conditions. The data indicate that the electronic link between CIII and CIV is confined to the surface of the supercomplex. Single-particle electron cryomicroscopy (cryo-EM) structures of the supercomplex with cyt. c show the positively charged cyt. c bound to either CIII or CIV or along a continuum of intermediate positions. Collectively, the structural and kinetic data indicate that cyt. c travels along a negatively charged patch on the supercomplex surface. Thus, rather than enhancing electron transfer rates by decreasing the distance that cyt. c must diffuse in three dimensions, formation of the CIII2CIV1/2supercomplex facilitates electron transfer by two-dimensional (2D) diffusion of cyt. c. This mechanism enables the CIII2CIV1/2supercomplex to increase QH2:O2oxidoreductase activity and suggests a possible regulatory role for supercomplex formation in the respiratory chain. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Bioenergetics; Cytochrome bc1; Cytochrome c oxidase; Electron transfer; Mitochondria
语种	英语
scopus关键词	adenosine triphosphate; cytochrome c; membrane protein; oxidoreductase; oxygen; reduced nicotinamide adenine dinucleotide; succinate dehydrogenase; succinic acid; Article; chemical structure; complex formation; controlled study; cryoelectron microscopy; diffusion; electron transport; enzyme activity; gel electrophoresis; hydrophobicity; kinetics; mitochondrial membrane; nonhuman; oxidation; oxidation reduction state; priority journal; proton transport; respiratory chain; Saccharomyces cerevisiae; static electricity
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180251
作者单位	Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Stockholm, SE-106 91, Sweden; Molecular Medicine program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Department of Medical Biophysics, The University of Toronto, Toronto, ON M5G 1L7, Canada; Department of Biochemistry, The University of Toronto, Toronto, ON M5S 1A8, Canada
推荐引用方式 GB/T 7714	Moe A.,Trani J.D.,Rubinstein J.L.,et al. Cryo-EM structure and kinetics reveal electron transfer by 2D diffusion of cytochrome c in the yeast III-IV respiratory supercomplex[J],2021,118(11).
APA	Moe A.,Trani J.D.,Rubinstein J.L.,&Brzezinski P..(2021).Cryo-EM structure and kinetics reveal electron transfer by 2D diffusion of cytochrome c in the yeast III-IV respiratory supercomplex.Proceedings of the National Academy of Sciences of the United States of America,118(11).
MLA	Moe A.,et al."Cryo-EM structure and kinetics reveal electron transfer by 2D diffusion of cytochrome c in the yeast III-IV respiratory supercomplex".Proceedings of the National Academy of Sciences of the United States of America 118.11(2021).