Abstract
In many prokaryotes and in organelles asparagine and glutamine are formed by a tRNA-dependent amidotransferase (AdT) that catalyzes amidation of aspartate and glutamate, respectively, mischarged on tRNA Asn and tRNA Gln. These pathways supply the deficiency of the organism in asparaginyl-and glutaminyl-tRNA synthtetases and provide the translational machinery with Asn-tRNA Asn and Gln-tRNA Gln. So far, nothing is known about the structural elements that confer to tRNA the role of a specific cofactor in the formation of the cognate amino acid. We show herein, using aspartylated tRNA Asn and tRNA Asp