Phylogenetic Analysis of aaRS Reveals the Kinship of Amino Acids

Abstract

Aminoacyl-tRNA synthetases catalyze the reaction of amino acids and the cognate tRNA. They are among the first proteins that emerged on the Earth. Here, we constructed and analyzed phylogenetic trees of eight aaRSs of which the respective amino acids are accessible in the prebiotic environment. We found that AlaRS and ValRS, LeuRS and SerRS are most similar in their aaRS dendrogram, also reflected in the chemical properties and codon triplets. The most distinct ArgRS implies arginine came later than other amino acids. Our analysis provides new ideas of the origin of amino acids and their cognate codon from the tRNA and protein level.