This family of proteins is found in eukaryotes. Proteins in this family are typically between 168 and 381 amino acids in length. Bot1p localizes to the mitochondria in live cells and cofractionates with purified mitochondrial ribosomes. Bot1p has a novel function in the control of cell respiration by acting on the mitochondrial protein synthesis machinery. Observations also indicate that in fission yeast, alterations of mitochondrial function are linked to changes in cell cycle and cell morphology control mechanisms.