The C-Ala Domain Brings Together Editing and Aminoacylation Functions on One tRNA

Abstract

Transfer RNA Fix Accurate protein synthesis requires that transfer RNAs (tRNAs) must be acylated with the correct amino acid. Mistranslation of serine or glycine for alanine apparently presents a particular challenge and is corrected by an editing domain of alanyl-tRNA synthetases (AlaRSs). Guo et al. (p. 744 ) now show that aside from the aminoacylation and editing domains, a third domain, C-Ala, plays a key role in AlaRS function. It forms a nucleic acid–binding motif that promotes binding of both aminoacylation and editing domains to tRNA Ala . The coupling of these two functions was likely important in the evolution of AlaRSs.