Leaky +1 and -1 frameshift mutations at the same site in a yeast mitochondrial gene.

Two mutations in a mitochondrial structural gene, which cause leaky premature polypeptide chain termination and leaky growth, are +1 and -1 frameshifts in the same run of five T residues. The partial restoration of reading frame is probably due to ribosomal frameshifting at this site, and may be promoted by the unique structure of the yeast mitochondrial t RNAPhe.