Aminoacyl-tRNA synthetases use a variety of mechanisms to ensure fidelity of the genetic
code and ultimately select the correct amino acids to be used in protein synthesis. The
physiological necessity of these quality control mechanisms in different environments
remains unclear, as the cost vs benefit of accurate protein synthesis is difficult to predict. We
show that in Escherichia coli, a non-coded amino acid produced through oxidative damage
is a significant threat to the accuracy of protein synthesis and must be cleared by …