Nucleotide sequence of a segment of human DNA containing the three tRNA genes.

A 1.65 kb segment of DNA from a human-lambda recombinant, selected for human tRNA genes, was subcloned in the plasmid pAT 153 for sequence determination. Three human tRNA genes were found; one, a tRNAlys gene which appears to specify a tRNA identical in sequence to the previously described tRNA3lys from rat liver (AAA,G); another a tRNAgln gene, the product of which would be expected to recognize only the codon CAG; and a third which would direct synthesis of a tRNAleu specific for CUA and G. Intervening sequences are not found in any of these genes. The three tRNA genes are separated by about 0.5 kb segments of DNA containing no apparent informational sequences. Examination of flanking sequences shows some similarities at the 5'-ends of the three genes, but less similarity to 5' flanking sequences of tRNA genes in other eucaryotes. All three tRNA genes direct synthesis of appropriate sized products in a HeLa cell lysate in vitro transcription system.