Spatial clustering of unique residues in snakes.

Sites at which positive selection was detected with greater than 90% posterior probability (Table S3) are shown in bold, as well as associations with functional regions. Distances between residue alpha carbons (Cα) were calculated from the bovine CO structure. All residue pairs marked with a * have closest side-chain van der Waals contact distances (excluding hydrogen) ≤5.0 Å.