Wobble modification defect in tRNA disturbs codon-anticodon interaction in a mitochondrial disease
| Autor: | Shigeo Ohta, Kimitsuna Watanabe, Takehiro Yasukawa, Norie Ishii, Tsutomu Suzuki |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Lysine-tRNA Ligase
Translational efficiency RNA Mitochondrial Mitochondrial translation Molecular Sequence Data Thiouridine Wobble base pair Peptide Elongation Factor Tu Biology MELAS syndrome DNA Mitochondrial Article General Biochemistry Genetics and Molecular Biology Cell Line MELAS Syndrome medicine Animals Humans Molecular Biology Genetics Binding Sites Base Sequence General Immunology and Microbiology General Neuroscience MERRF syndrome Translation (biology) medicine.disease MERRF Syndrome Mitochondria Protein Biosynthesis Mutation Transfer RNA Nucleic Acid Conformation RNA RNA Transfer Lys Cattle EF-Tu HeLa Cells |
| Zdroj: | The EMBO Journal. 20:4794-4802 |
| ISSN: | 1460-2075 |
| DOI: | 10.1093/emboj/20.17.4794 |
| Popis: | We previously showed that in mitochondrial tRNA(Lys) with an A8344G mutation responsible for myoclonus epilepsy associated with ragged-red fibers (MERRF), a subgroup of mitochondrial encephalomyopathic diseases, the normally modified wobble base (a 2-thiouridine derivative) remains unmodified. Since wobble base modifications are essential for translational efficiency and accuracy, we used mitochondrial components to estimate the translational activity in vitro of purified tRNA(Lys) carrying the mutation and found no mistranslation of non-cognate codons by the mutant tRNA, but almost complete loss of translational activity for cognate codons. This defective translation was not explained by a decline in aminoacylation or lowered affinity toward elongation factor Tu. However, when direct interaction of the codon with the mutant tRNA(Lys) defective anticodon was examined by ribosomal binding analysis, the wild-type but not the mutant tRNA(Lys) bound to an mRNA- ribosome complex. We therefore concluded that the anticodon base modification defect, which is forced by the pathogenic point mutation, disturbs codon- anticodon pairing in the mutant tRNA(Lys), leading to a severe reduction in mitochondrial translation that eventually could result in the onset of MERRF. |
| Databáze: | OpenAIRE |
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