MITOCHONDRIAL GENETICS. XII. AN OLIGOMYCIN-RESISTANT MUTANT LOCALIZED AT A NEW MITOCHONDRIAL LOCUS IN SACCHAROMYCES CEREVISIAE

Three antibiotic-resistance mutations were isolated from strain FL496–2B: two are independent Mendelian genes, one conferring both oligomycin and venturicidin resistance (oliR  496) and the other conferring cycloheximide resistance (cyhR  496). The third is a mitochondrial mutation, OR  9, and confers a low level of oligomycin resistance to cells (in vivo) but not to the extracted mitochondrial ATPase (in vitro). This mutation is located on the mitochondrial DNA at a new locus [OLI4] linked to [OLI2] and independent from [OLI1] and [OLI3] and from the other mitochondrial loci. All three mutations (OR  9, oliR  496, cyhR  496) were found without any selection, in the same prototrophic haploid strain, which contained unknown resistances to antibiotics. Some physiological, genetical and biochemical properties of the mitochondrial mutation are described.