Mitochondrial aspartate aminotransferase (  maa1  ) inactivation causes glutamate-requiring  glu1  mutation in  Schizosaccharomyces   pombe .
Two genomic genes, which rescue ammonium assimilation defect in the glutamate-requiring  Schizosaccharomyces   pombe glu1  mutant, were identified. The  maa1  , encoding a mitochondrial aspartate aminotransferase, is the causative gene of  glu1  mutation because an inseparable linkage between  maa1  and  glu1  on the chromosome, and also the  glu1  mutant strain has a nonsense mutation within the  maa1  coding region, which is responsible for its defective phenotype. The  yhm2  , a mitochondrial 2-oxoglutarate carrier, was also isolated as a weak multicopy suppressor gene. These findings reiterate the importance of the mitochondria in utilizing the amino acids for cellular nitrogen metabolism.
Kitamura K