Takeda M, Katayama H, Satoh T, Mabuchi T. Three copies of the ATP2 gene are arranged in tandem on chromosome X in the yeast Saccharomyces cerevisiae. Curr Genet. 2005;47:265-72 pubmed
..In addition, of the three copies of ATP1 and ATP2, even if only one copy of the ATP1 and ATP2 genes remained, the cells grew on glycerol. ..