Sequence rearrangements at the ori 7 region of Saccharomyces cerevisiae mitochondrial DNA.

Three ori elements (ori 2, ori 5, and ori 7) have been sequenced in Saccharomyces cerevisiae strain Dip 2 and compared to the equivalent ori elements of a second strain (B). Both ori 2 and ori 5 exhibit 98% base matching between strains Dip 2 and B. In contrast, the third ori element (ori 7) exhibits extensive sequence rearrangements whereby a segment located downstream in the consensus strain occurs within the ori structure in Dip 2. This represents a novel polymorphic form of the yeast mitochondrial genome.