Electrostatic Interactions between Complement Regulator CD46(SCR1-2) and Adenovirus Ad11/Ad21 Fiber Protein Knob

Figure 4

Electrostatic free energies of binding for CD46(SCR1-2) mutants in complex with Ad11k (a) and Ad21k (b). Charged residues in CD46(SCR1-2) were systematically mutated into alanine, one at a time as described in the text, to generate a family of as many mutants as ionizable residues in the protein. The type of residue, residue number, and chain letter (in parentheses) for each mutant are shown. Negative and positive values represent increased and decreased thermodynamic stability of mutant complexes relative to WT (parent), respectively. Highlighted residues are involved in specific binding and are grouped based on the distance of their closest Coulombic interaction. All other charged residues have weak or diminishing Coulombic interactions at more than 8 Å apart. The order of CD46(SCR1-2) mutants in (a) and (b) corresponds to the order in the dendrograms of Figures S4 and S5, respectively.

(a)

(b)