... by 6–8 orders of magnitude [2] and finally induces the release of the TetR–[Mg–Tc]+ternary complex, thereby initiating expression of TetA [3,4]. Regulation of TetR by binding of [Mg–Tc]+takes ... binding of [Mg–Tc]+takes place in the core of the repressor, which is formed byhelices a5toa10 of both subunits. Study of the crystalstructure of the TetR homodimer in complex with itspalindromic ... concentration of 0.4 mgÆmL)1andscan rate of 1 KÆmin)1, Tmaxis 60.4 °C. The denaturationtemperature, Tmax, of the complex of TetR with Tc is70.4 °C, measured at a protein concentration of 0.4...