Glutamyl tRNA Amidotransferase Subunit D (GATD)

GATD belongs to the asparaginase 1 family. GatD subfamily. Allows the 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 gatDE system is specific for glutamate and does not act on aspartate.

In archeabacteria, GatD and GatE carry out the amidotransferase reactions on Gln tRNAs. Although GatA proteins are highly conserved in prokaryotes, fungi, and animals, the gatA alleles described here are the first reported eukaryotic gatA mutants. The only other characterized eukaryotic mutants in this pathway are defective in Saccharomyces cerevisiae pet112. Intriguingly, pet112 cells are small, but viable.