Identification and isolation of the cytochrome oxidase subunit II gene in mitochondria of the yeast Hansenula saturnus

Summary Mitochondrial DNA from the petite negative yeast Hansenula saturnus has been isolated and sized by digestion with restriction enzymes. The size of the mitochondrial genome is approximately 47 kb. The gene for subunit II of cytochrome oxidase was localized in the genome by Southern blotting using a [³²P]-labeled probe containing the subunit II gene of the yeast Saccharomyces cerevisiae. The probe hybridized to a 1.7 kb HindIII-BamHI fragment under stringent conditions (65°C), indicating a high degree of homology between the S. cerevisiae and H. saturnus mitochondrial DNA fragments. The 1.7 kb fragment from H. saturnus was cloned into pBR322 and physically mapped. The map was used to obtain the nucleotide sequence of the subunit II gene (Lawson and Deters presented in the accompanying paper).