The Nucleotide Sequence of the tRNA{ie} from the Archaebacterium Thermoplasma acidophilum

The nucleotide sequence of Thermoplasma acidophilum tRNA{ie} has been shown to be: pGCCGGGGs⁴UGGCUCANCUGGAGGAGCm₂²GCCGGAC_m UCAUt⁶AAUCCGGAG-GUCUCGGGψψC_mGAUCCCCGAUCCCGGCACCA_oH. The tRNA contains eight modified nucleosides including the sequence ψψC_m (54–56) which has been proposed as a unique feature of archaebacterial tRNAs. One modification is unknown but it is likely to be typically archaebacterial (N-15). Of the remaining four, one (s⁴U-8) is a typical eubac-terial modification and one (m₂²G-26) is a typical eukaryotic modification. The sequence shows little homology with any other published tRNA but shows almost 90% homology with the ancestral quasi-species sequence deduced by Eigen and Winter-Oswatitsch (1981).