Codons under positive diversifying selection encode amino acid residues at the ROP5BI /IRGa6 interface.

(A) Structure of T. gondii ROP5BI (grey) bound to murine Irga6 (tan) showing amino acid residues under positive diversifying selection (red), ROP5BI residues at the ROP5BI /Irga6 interface (blue), and residues that are under positive diversifying selection and at the interface (purple). (B) Both panels are a rotation of 60° about the x-axis with respect to A, showing ROP5BI with Irga6 removed for clarity. The color scheme is as in A. Bottom panel is a surface representation showing the overlap in surface residues. The top panel shows the position of all amino acid residues under positive diversifying selection.