This mutation switches off the repressor protein, allowing RT027 to use low levels of trehalose.

A chimeric transactivator comprises a transcription activation domain, a repressor protein DNA binding domain and the bacterial DNA gyrase B subunit.

When the repressor protein binds, RNA polymerase cannot initiate transcription and no mRNA is produced.

Using one such aptamer, inducible post-transcriptional regulation in vivo has been demonstrated that is predicated on a direct interaction between a tetracycline repressor protein and a RNA aptamer element.

In vitro SELEX has been used to discover high affinity RNA aptamers interacting with the tetracycline repressor protein in a tetracycline-dependent manner.