Two conserved sequence blocks within eukaryotic tRNA genes are major promoter elements

Abstract
The split promoter sequences of a .**GRAPHIC**. gene of Xenopus laevis were mapped to nucleotides 13-20 and 51-64 of the tRNALeu coding sequences. The sequences closely coincide with 2 conserved sequence blocks present in all eukaryotic tRNA genes. The 2 conserved sequence blocks were found to be exchangeable between tRNA genes as chimeric tRNAMet -tRNALeu genes proved transcriptionally active. Two prokaryotic tRNA genes exhibiting strong homologies with the 2 blocks yielded specific transcripts when tested in an eukaryotic transcriptional system.
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