rRNA Suppressor of a Eukaryotic Translation Initiation Factor 5B/Initiation Factor 2 Mutant Reveals a Binding Site for Translational GTPases on the Small Ribosomal Subunit
| Autor: | Jon R. Lorsch, Joo Ran Kim, Thomas E. Dever, Kathryn N. Maher, Byung Sik Shin, Michael G. Acker |
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| Rok vydání: | 2009 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Amino Acid Motifs Eukaryotic Initiation Factor-2 Molecular Sequence Data Saccharomyces cerevisiae Biology GTP Phosphohydrolases Peptide Elongation Factor 1 Suppression Genetic Eukaryotic translation Eukaryotic initiation factor Translational regulation RNA Ribosomal 18S Initiation factor Histidine Eukaryotic Small Ribosomal Subunit Amino Acid Sequence Genes Suppressor Molecular Biology Conserved Sequence eIF2 Binding Sites Base Sequence Hydroxyl Radical Articles Cell Biology Protein Structure Tertiary Ribosome Subunits Small Amino Acid Substitution Biochemistry Protein Biosynthesis Eukaryotic Ribosome |
| Zdroj: | Molecular and Cellular Biology. 29:808-821 |
| ISSN: | 1098-5549 |
| DOI: | 10.1128/mcb.00896-08 |
| Popis: | The translational GTPases promote initiation, elongation, and termination of protein synthesis by interacting with the ribosome. Mutations that impair GTP hydrolysis by eukaryotic translation initiation factor 5B/initiation factor 2 (eIF5B/IF2) impair yeast cell growth due to failure to dissociate from the ribosome following subunit joining. A mutation in helix h5 of the 18S rRNA in the 40S ribosomal subunit and intragenic mutations in domain II of eIF5B suppress the toxic effects associated with expression of the eIF5B-H480I GTPase-deficient mutant in yeast by lowering the ribosome binding affinity of eIF5B. Hydroxyl radical mapping experiments reveal that the domain II suppressors interface with the body of the 40S subunit in the vicinity of helix h5. As the helix h5 mutation also impairs elongation factor function, the rRNA and eIF5B suppressor mutations provide in vivo evidence supporting a functionally important docking of domain II of the translational GTPases on the body of the small ribosomal subunit. Four universally conserved GTPases interact with the ribosome to coordinate the initiation, elongation, and termination of protein synthesis. Initiation factor 2/eukaryotic translation |
| Databáze: | OpenAIRE |
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