Identification of U(p)47 in three thermophilic archaea, one mesophilic archaeon, and one hyperthermophilic bacterium

Analysis of the profile of the tRNA modifications in several Archaea allowed us to observe a novel modified uridine in the V-loop of several tRNAs from two species: Pyrococcus furiosus and Sulfolobus acidocaldarius. Recently, Ohira and colleagues characterized 2′-phosphouridine (U(p)) at position 47 in tRNAs of thermophilic Sulfurisphaera tokodaii, as well as in several other archaea and thermophilic bacteria. From the presence of the gene arkI corresponding to the RNA kinase responsible for U(p)47 formation, they also concluded that U(p)47 should be present in tRNAs of other thermophilic Archaea. Reanalysis of our earlier data confirms that the unidentified residue in tRNAs of both P. furiosus and S. acidocaldarius is indeed 2′-phosphouridine followed by m(5)C48. Moreover, we find this modification in several tRNAs of other Archaea and of the hyperthermophilic bacterium Aquifex aeolicus.