Figure 7.

RecR reduces the affinity of RecO for the SSB Ct acidic tip peptide. Results of ITC titrations (buffer BTP, pH 8 at 25°C) of RecO (2 μM) with P15 peptide fit to a 1:1 binding model with equilibrium binding constant of (1.2 ± 0.3) × 10⁷ M⁻¹ and ΔH = –5.2 ± 0.1 kcal/mol (reproduced from (26), blue), and a mixture of RecO (2 μM) and RecR (8 μM monomer) (1:4 molar ratio) with P15 (orange). In the presence of RecR, the RecO–P15 binding enthalpy, ΔH, is significantly reduced to less than 1 kcal/mol with lower apparent binding affinity. A reference titration of RecR with P15 (open circles) indicates no binding of P15 to RecR.