Mutational study of the rRNA in yeast mitochondria: functional importance of T1696 in the large rRNA gene.

Four intragenic suppressors of a mitochondrial mutation in the 21S rRNA gene have been characterized in S. cerevisiae. The determination of the nature of the nucleotide changes in the suppressor strains showed that a T at position 1696 in the large rRNA gene is essential for correct function of the mitoribosome. The importance of this specific nucleotide and the fact that this mitochondrial mutation can also be suppressed by a mutation in a nuclear gene are in good agreement with a rRNA-r protein interaction in this part of domain IV, which functional importance is demonstrated in vivo by our results.