@article {Agmon559948, author = {Ilana Agmon and Itay Fayerverker and Tal Mor}, title = {Coding triplets in the transfer RNA arm and their role in present and past tRNA recognition}, elocation-id = {559948}, year = {2019}, doi = {10.1101/559948}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Background The evolutionary pathway of tRNA established the linking of the genetic code and protein synthesis, thus, revealing the characteristics of the prebiotic tRNA is crucial for presenting a feasible scenario for the emergence of life.Results Analysis of bacterial tRNA sequences reveals that for nine amino acids, mostly those considered to be the most ancient ones, the acceptor-TψC arm carries cognate coding triplets far beyond statistical expectation. The contemporary determinants for the recognition of tRNAs and minihelices by the cognate synthetases and by EF-Tu, are part of these conserved triplets. We also find a strong correlation between the extent of the coding triplet conservation and amino acids whose contemporary synthetases belong to class Ila.Conclusions Identification of conserved coding triplets within the tRNA acceptor-TψC stem, along with the analysis of their distinctive layout, is suggestive of a continuous evolutionary path that could have led to the appearance of the early translation system.aaamino acidaaRSaminoacyl-tRNA synthetaseACanticodonC/ACcodon and/or anticodon tripletPre-3{\textquoteright}end10 mer string preceding the tRNA 3{\textquoteright}end}, URL = {https://www.biorxiv.org/content/early/2019/02/25/559948}, eprint = {https://www.biorxiv.org/content/early/2019/02/25/559948.full.pdf}, journal = {bioRxiv} }