Glutamyl tRNA Amidotransferase Subunit B (GATB)

In S. cerevisiae, a mutation in the pet112 gene specifically blocks accumulation of cytochrome oxidase (COX) subunit II. Disruption of the pet112 gene destabilizes the mitochondrial genome, suggesting that the pet112 protein plays an important general role in mitochondrial gene expression, most likely in translation.

The predicted 557-amino acid human protein shares 30% identity with yeast pet112. PET112L contains a mitochondrial leader peptide, and in vitro mitochondrial import and trypsin-protection assays demonstrated that it is targeted to mitochondria. Northern blot analysis revealed that PET112L is predominantly expressed in tissues characterized by high rates of oxidative phosphorylation (OXPHOS), including muscle and heart.