Each element of theDrosophilatRNAArggene split promoter directs transcription inXenopusoocytes

The intragenic control regions of a eukaryotic tRNA gene have been examined by transcribing mutant forms of a Drosophila tRNAArg gene either by injection into the nucleus of Xenopus oocytes or in extracts prepared from isolated oocyte nuclei. These experiments demonstrate that the selection of the transcription initiation site is a complex mechanism that involves the T-control region, the D-control region, and sequences 5' adjacent to the D-control region. In this study either "half" of the Drosophila tRNAArg gene promoted transcription in Xenopus oocytes. This finding supports a recent model for eukaryotic tRNA gene transcription (Dingermann et al., 1983, J. Biol. Chem. 258, 10395-10402) that proposes transcription initiation is dependent on the ability of specific DNA sequences to sequester two RNA polymerase III transcription factors.