Table 3.

Affinities and thermodynamic parameters of the TetR–RNA aptamer and TetR–DNA complexes

	K d (nM)	n a	ΔH (kJ mol−1)	ΔS (J mol−1 K−1)	–TΔS (kJ mol−1)	ΔG (kJ mol−1)
TetR–RNA aptamer K1 complex formation
TetR	5.6	0.96	−156.0	−365.2	108.8	−47.2
TetR–Q38A	26.2	1.10	−152.8	−367.2	109.4	−43.4
TetR–Y42A	13.9 × 103	1b	−74.6	−157.1	46.8	−27.8
TetR–DNA tetO operator complex formation
TetR	51.1	1.17	57.7	336.4	−100.2	−42.5
TetR–Q38A	432.7	1.11	53.4	300.9	−89.7	−36.3

^a N = 1 signifies that one TetR dimer interacts with one RNA aptamer molecule or dsDNA fragment.

^b N = 1 was kept fixed during data evaluation.