Suppression of a mitochondrial point mutation in a tRNA gene can cast light on the mechanisms of 3' end-processing.
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 hydrogen-bond 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 degrees C on glycerol medium in heterozygous diploids, but leads to a defective growth phenotype in haploids.
Rinaldi
T
T
Laboratoire de Génétique Moléculaire, Université Paris-Sud, Orsay, France.
Francisci
S
S
Zennaro
E
E
Frontali
L
L
Bolotin-Fukuhara
M
M
D001483:Base Sequence; D004171:Diploidy; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010641:Phenotype; D017354:Point Mutation; D012313:RNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000077278:RNA, Mitochondrial; D012349:RNA, Transfer, Asp / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D013489:Suppression, Genetic
D012331:RNA, Fungal; D000077278:RNA, Mitochondrial; D012349:RNA, Transfer, Asp; D012313:RNA