Characterization of tRNA genes in tRNA region II of yeast mitochondrial DNA.

We have isolated individual mitochondrial tRNAs from a petite mutant OI-P2-1 known to contain a limited subset of mitochondrial tRNA genes and have mapped these genes on the wild type genome of the yeast strains MH41-7B and D273-10B. To obtain DNA for fine structure mapping and DNA sequence analysis of these genes, we screened a yeast mitochondrial DNA-pBR322 recombinant bank with the isolated tRNAs. We report here the fine structure mapping of recombinant clones containing the tryptophan, formyl methionine and proline tRNA genes as well as the DNA sequence of the proline tRNA gene. The combination of restriction mapping and DNA sequence analysis has enabled us to locate these genes precisely on the wild type genome and to determine their direction of transcription.