The function of GATB (glutamyl-tRNA amidotransferase subunit B, Ensembl gene identifier ENSG00000059691) is as follows. Allows the formation of correctly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in the mitochondria. The reaction takes place in the presence of glutamine and ATP through an activated gamma-phospho-Glu-tRNA(Gln). .