The Tn10-encoded tetR mRNA has heterogeneous 5' ends in vivo and in vitro.
The 5' ends of the Tn10-encoded mRNAs have been analyzed by quantitative primer extensions of the in vivo synthesized RNA and in vitro run-off transcription. The gene is transcribed by a tandem promoter system consisting of PR1 and PR2. While PR1 contributes about 25% of the total PR activity in vitro, more than 95% of the in vivo-produced transcripts originate from PR2. Transcription from PR2 shows extensive heterogeneity at the 5' ends of the mRNAs in vitro and most likely also in vivo. A deletional and oligodeoxyribonucleotide-directed mutational analysis of the PR2 transcript reveals that length heterogeneity results from reiterative copying of a run of five A's at the transcription start point. In vivo transcription leads to longer reiteration products than in vitro transcription.
Gülland
U
U
Lehrstuhl für Mikrobiologie, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany.
Hillen
W
W
D001483:Base Sequence; D004252:DNA Mutational Analysis; D004251:DNA Transposable Elements / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D013753:Tetracycline Resistance / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics*
D004251:DNA Transposable Elements; D012333:RNA, Messenger