<p>Glutamyl-tRNA(Gln) amidotransferase subunit B (<db_xref db="EC" dbkey="6.3.5"/>) [<cite idref="PUB00007932"/>] is a microbial enzyme that furnishes a means for formation of correctly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in organisms which lack glutaminyl-tRNA synthetase. The reaction takes place in the presence of glutamine and ATP through an activated gamma-phospho-Glu-tRNA(Gln). The enzyme is composed of three subunits: A (an amidase), B and C. It also exists in eukaryotes as a protein targeted to the mitochondria. </p>