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Binding of a viral IRES to the 40S subunit occurs in two successive steps mediated by eS25.
- Source :
-
Nucleic acids research [Nucleic Acids Res] 2020 Aug 20; Vol. 48 (14), pp. 8063-8073. - Publication Year :
- 2020
-
Abstract
- The mechanism for how internal ribosome entry sites (IRESs) recruit ribosomes to initiate translation of an mRNA is not completely understood. We investigated how a 40S subunit was recruited by the cricket paralysis virus intergenic region (CrPV IGR) IRES to form a stable 40S-IRES complex. Kinetic binding studies revealed that formation of the complex between the CrPV IGR and the 40S subunit consisted of two-steps: an initial fast binding step of the IRES to the 40S ribosomal subunit, followed by a slow unimolecular reaction consistent with a conformational change that stabilized the complex. We further showed that the ribosomal protein S25 (eS25), which is required by functionally and structurally diverse IRESs, impacts both steps of the complex formation. Mutations in eS25 that reduced CrPV IGR IRES activity either decreased 40S-IRES complex formation, or increased the rate of the conformational change that was required to form a stable 40S-IRES complex. Our data are consistent with a model in which eS25 facilitates initial binding of the CrPV IGR IRES to the 40S while ensuring that the conformational change stabilizing the 40S-IRES complex does not occur prematurely.<br /> (© The Author(s) 2020. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Subjects :
- Binding Sites
DNA, Intergenic genetics
DNA, Intergenic metabolism
Dicistroviridae genetics
Mutation
Protein Binding
Ribosomal Proteins chemistry
Ribosomal Proteins genetics
Ribosome Subunits, Small, Eukaryotic chemistry
Ribosome Subunits, Small, Eukaryotic genetics
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins chemistry
Saccharomyces cerevisiae Proteins genetics
Internal Ribosome Entry Sites
Ribosomal Proteins metabolism
Ribosome Subunits, Small, Eukaryotic metabolism
Saccharomyces cerevisiae Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1362-4962
- Volume :
- 48
- Issue :
- 14
- Database :
- MEDLINE
- Journal :
- Nucleic acids research
- Publication Type :
- Academic Journal
- Accession number :
- 32609821
- Full Text :
- https://doi.org/10.1093/nar/gkaa547