Three previously described genes that affect bakers' yeast (Saccharomyces cerevisiae) mitochondrial DNA (mtDNA) or mitochondrial RNA, tpm2-1, mna1-1, and mgm1-1, are shown to be alleles of the same gene. This report demonstrates that tpm2-1 does not affect recombination of mtDNA. Therefore, there is no evidence that this dynamin-like protein is involved in movement of mtDNA within a cell.