Inhibition of eukaryotic tRNA transcription by potential Z-DNA sequences.
The effect of d(CA/TG)n DNA segments on tRNA transcription has been examined. Alternating purine-pyrimidine tracts were cloned at a long distance from, adjacent to, or within the coding sequence of a tRNAPro gene from Caenorhabditis elegans and shown to be able to assume the A-DNA conformation in vitro in physiological salt concentrations. The transcriptional level of these constructs was compared to that of normal tDNAPro by micro-injection into Xenopus laevis oocytes. Our results show a strong inhibitory effect by potential Z-DNA sequences only when these are placed in the flanking regions of the gene or when they are located between the elements (Box A and Box B) of the split promoter. Transcription was studied in parallel with supercoiled and linear DNA molecules carrying a d(CA/TG) stretch 124-bp long in front of the tRNAPro gene. The results show the same level of inhibition of Po/III transcription regardless of the topological status of the injected DNA.
D000818:Animals; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D008040:Genetic Linkage; D009865:Oocytes; D009876:Operon; D010957:Plasmids; D011392:Proline; D012343:RNA, Transfer / Q000235:genetics*; D014158:Transcription, Genetic; D014982:Xenopus laevis
D004247:DNA; D012343:RNA, Transfer; D011392:Proline