MST analysis of the binding interactions between Sir4 H‑BRCT and Cy5-labeled phospho (filled circles) and non-phospho peptides (empty circles) from Esc1, Ty5 and Ubp10. KD = equilibrium dissociation constant. ΔFnorm values were divided by the amplitude of the saturation level, resulting in the fraction bound (from 0 to 1) for each data point. Data are represented as the mean ± SEM from ≥3 independent measurements. 