c-di-AMP binding of KtrA proteins and its variants are measured by ITC.
A, KtrA RCK_C domain wild-type, (B) D167A, (C) D167K, (D) N175A, (E) R169A, (F) R169E, (G) I163A/I164A, and (H) I176A/I177A. Original titration data and integrated heat measurements are shown in the upper and lower plots, respectively.