Skip to main content
. 2013 Sep 10;11(9):e1001651. doi: 10.1371/journal.pbio.1001651

Figure 2. The influence of third-site mutations on allostery in CAP.

Figure 2

(A) Predicted influence of mutation of V132 on allostery in CAP. The chart represents the ratio of the second to first dissociation constants for cAMP (K 2/K 1) plotted against spring constant at V132 (k V132/k). The structures are the proposed corresponding mutations. (B) Close-up of the X-ray crystal structures for CAP variants showing the hydrophobic interaction surface at amino acid 132 in wild-type, V132L, and V132A proteins. (C–E) ITC traces (upper panel) and binding isotherms (lower panel; the different coloured symbols represent individual experiments) for the calorimetric titration of cAMP to CAP wild-type (C), V132L (D), or V132A (E). The thermodynamic parameters obtained are summarized in Tables 1 and S2.