Figure 6.

(A) Representation of CICD residues in the structure of human hemoglobin. The two α and two β subunits are colored in magenta and yellow, respectively. CICD residues belonging to α subunits are located at the α₁β₁ (α₂β₂) interfaces (inside the hemoglobin central cavity, green) and at the interfaces α₁β₂ (α₂β₁) (red), whereas those from β subunits are part of the α₁β₁ (α₂β₂) and α₁β₂ (α₂β₁) interfaces (blue). (B) CICD residues forming part of the network of statistically coupled residues, as identified by Ranganathan and collaborators. The two α and two β subunits are colored in magenta and yellow, respectively. CICD residue Phe98 belonging to both α subunits is shown in green, and forms part of the network of coupled residues.