The role of a conserved dodecamer sequence in yeast mitochondrial gene expression.
All mRNAs on the yeast mitochondrial genome terminate at a conserved dodecamer sequence 5'-AAUAAUAUUCUU-3'. We have characterized two mutants with altered dodecamers. One contains a deletion of the dodecamer at the end of the var1 gene, and the other contains two adjacent transversions in the dodecamer at the end of the reading frame of fit1, a gene within the omega+ allele of the 21S rRNA gene. In each mutant, expression of the respective gene is blocked completely. A dominant nuclear suppressor, SUV3-1, was isolated that suppresses the var1 deletion but is without effect on the fit1 dodecamer mutations. Unexpectedly, however, we found that SUV3-1 blocks expression of the wild-type fit1 allele by blocking processing at its dodecamer. SUV3-1 has pleiotropic effects on mitochondrial gene expression, affecting RNA processing, RNA stability, and translation. Our results suggest that RNA metabolism and translation may be part of a multicomponent complex within mitochondria.
Butow
R A
RA
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235.
Zhu
H
H
Perlman
P
P
Conrad-Webb
H
H
D001483:Base Sequence; D004271:DNA, Fungal / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D012323:RNA Processing, Post-Transcriptional; D012331:RNA, Fungal / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D013489:Suppression, Genetic
D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D012331:RNA, Fungal; D012333:RNA, Messenger