Aminoacyl-tRNA synthetase charging a tRNA

The ability of each aminoacyl-tRNA synthetase to recognize an appropriate tRNA has been called the second genetic code. A precise recognition process is necessary to maintain the fidelity of genetic information. If the wrong amino acid was attached to a tRNA, the amino acid sequence of the translated polypeptide would be incorrect. To prevent this from happening, aminoacyl-tRNA synthetases are amazingly accurate enzymes. The wrong amino acid is attached to a tRNA fewer than 1 in 100,000 times. The anticodon region of the tRNA is usually important for recognition by the correct aminoacyl-tRNA synthetase. In addition, the acceptor stem and base sequences in other stem-loop regions may facilitate binding to an aminoacylt-RNA synthetase.