The ribosome termination complex remodels release factor RF3 and ejects GDP.

Autor: Li L; State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China.; Center for mRNA Translational Research, Fudan University, Shanghai, China., Rybak MY; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA., Lin J; State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China. linjinzhong@fudan.edu.cn.; Center for mRNA Translational Research, Fudan University, Shanghai, China. linjinzhong@fudan.edu.cn., Gagnon MG; Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA. magagnon@utmb.edu.; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA. magagnon@utmb.edu.; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA. magagnon@utmb.edu.; Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA. magagnon@utmb.edu.
Jazyk: angličtina
Zdroj: Nature structural & molecular biology [Nat Struct Mol Biol] 2024 Dec; Vol. 31 (12), pp. 1909-1920. Date of Electronic Publication: 2024 Jul 19.
DOI: 10.1038/s41594-024-01360-0
Abstrakt: Translation termination involves release factors RF1, RF2 and the GTPase RF3 that recycles RF1 and RF2 from the ribosome. RF3 dissociates from the ribosome in the GDP-bound form and must then exchange GDP for GTP. The 70S ribosome termination complex (70S-TC) accelerates GDP exchange in RF3, suggesting that the 70S-TC can function as the guanine nucleotide exchange factor for RF3. Here, we use cryogenic-electron microscopy to elucidate the mechanism of GDP dissociation from RF3 catalyzed by the Escherichia coli 70S-TC. The non-rotated ribosome bound to RF1 remodels RF3 and induces a peptide flip in the phosphate-binding loop, efficiently ejecting GDP. Binding of GTP allows RF3 to dock at the GTPase center, promoting the dissociation of RF1 from the ribosome. The structures recapitulate the functional cycle of RF3 on the ribosome and uncover the mechanism by which the 70S-TC allosterically dismantles the phosphate-binding groove in RF3, a previously overlooked function of the ribosome.
Competing Interests: Competing interests: The authors declare no competing interests.
(© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)
Databáze: MEDLINE
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