Suppression of a mitochondrial point mutation in a tRNA gene can cast light on the mechanisms of 3′ end-processing
✍ Scribed by Teresa Rinaldi; Silvia Francisci; Elisabetta Zennaro; Laura Frontali; Monique Bolotin-Fukuhara
- Book ID
- 104735488
- Publisher
- Springer-Verlag
- Year
- 1994
- Tongue
- English
- Weight
- 879 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0172-8083
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✦ Synopsis
We used a genetic approach to study the nuclear factors involved in the biogenesis of mitochondrial tRNAs. A point mutation in the mitochondrial tRNA ASp gene of Saccharomyces cerevisiae had previously been shown to result in a temperature-sensitive respiratory-deficient phenotype as a result of the absence of 3' end-processing of the tRNA Asp. Analysis of mitochondrial revertants has shown that all revertants sequenced have a G-A compensatory change at position 53, which restores the hydrogenbond with the mutated nucleotide. We then searched for nuclear suppressors to identify the nuclear gene(s) involved in mitochondrial tRNA 3' end-processing. One such suppressor mutation was further characterized: it restores tRNA Asp maturation and growth at 36 ~ on glycerol medium in heterozygous diploids, but leads to a defective growth phenotype in haploids.