Identification of Up47 in three thermophilic archaea, one mesophilic archaeon, and one hyperthermophilic bacterium

Analysis of the profile of the tRNA modifications in severalArchaeaallowed us to observe a novel modified uridine in the V-loop of several tRNAs from two species:Pyrococcus furiosusandSulfolobus acidocaldarius. Recently, Ohira and colleagues characterized 2′-phosphouridine (Up) at position 47 in tRNAs of thermophilicSulfurisphaera tokodaii, as well as in several other archaea and thermophilic bacteria. From the presence of the genearkIcorresponding to the RNA kinase responsible for Up47 formation, they also concluded that Up47 should be present in tRNAs of other thermophilicArchaea. Reanalysis of our earlier data confirms that the unidentified residue in tRNAs of bothP. furiosusandS. acidocaldariusis indeed 2′-phosphouridine followed by m5C48. Moreover, we find this modification in several tRNAs of otherArchaeaand of the hyperthermophilic bacteriumAquifex aeolicus.