Design of Multi-Specificity in Protein Interfaces
Figure 7
Distribution of Constraint Scores in Promiscuous Interfaces
Tradeoff at each interface position in our dataset was estimated by the per-residue difference in scores of amino acids chosen when each partner was optimized alone as compared with when all binding partners were considered in the optimization procedure (see Figure 1A2). The percentage of interface sites displaying the lowest level (0–0.5) of “tradeoff value” (see Methods and text) is shown for all 20 proteins in our dataset (A). Such positions are predicted to be highly shared, in that no partner considered had to “give up” potential gain so that other partners could fulfill their optimal interactions. Blue and pink shading denotes whether each protein was assigned to group I or II. Right-hand panels show color-coded mappings of constraint scores onto three promiscuous protein interfaces calculated to display high (B) (Ran set #11), medium (C) (CheY set #4), and low (D) (Ovomucoid Inhibitor set #3) compromise. Compromise values are colored as follows: 0–0.5, wheat; 0.5–1 yellow; 1–1.5 orange; >1.5 red.