A yeast protein, homologous to the proteolipid of the chromaffin granule proton-ATPase, is important for cell growth.

We have characterized a gene, PPA1, adjacent to the yeast MAS2 gene. DNA sequence analysis of PPA1 predicts a hydrophobic protein of 23 kDa. This protein is homologous to the proteolipid of the bovine chromaffin granule proton ATPase and to the proteolipid of the yeast vacuolar proton ATPase. Gene disruption experiments indicate that the PPA1 protein is essential for viability in three unrelated yeast strains and important for optimal growth in a fourth strain.