Abstract
Expression of the mercury-resistance (mer) genes of the transposon Tn501 is positively and negatively controlled by the product of the merR gene. DNA sequence analysis has identified three open reading frames as potential candidates for this gene, one of which is oriented divergently with respect to the mercury-resistance genes. We have demonstrated that although RNA polymerase will bind to fragments containing the potential control regions for all three reading frames, only the control region for this divergent reading frame shows detectable promoter activity in vivo. Transcription of this reading frame is required for repression and induction of mer transcription. We have also shown that the Tn501 merR gene product negatively regulates its own synthesis, and have identified the start point of the transcript for this reading frame and for the mercury-inducible transcript of the mercury-resistance genes.
| Original language | English |
|---|---|
| Pages (from-to) | 465-80 |
| Number of pages | 16 |
| Journal | Journal of general microbiology |
| Volume | 132 |
| Issue number | 2 |
| Publication status | Published - Feb 1986 |
Keywords
- R Factors
- Promoter Regions, Genetic
- Genes, Bacterial
- beta-Galactosidase
- Escherichia coli
- DNA Transposable Elements
- Mercury
- Enzyme Induction
- Transcription, Genetic
- Gene Expression Regulation
- Plasmids
- DNA-Directed RNA Polymerases