FIGURE 1.

Elbow angle, ABangle (HL angle), and C_H1–C_L interface angle definitions depicted as Lego models. The constant domains are illustrated in dark green (C_H1) and dark blue (C_L), while the variable domains are shown in light green (V_H) and light blue (V_L). To calculate the C_H1–C_L interface angle, we defined a torsion angle between the center of mass of the C-terminal loops of the C_H1 domain, the center of mass of C_H1, the center of mass of the C_L domain, and the center of mass of the C-terminal loops of the C_L domains. The center of masses of the C_H1 and C_L C-terminal loops are depicted in this figure, as C_L and C_H1 loops. For the elbow angle definition, all used centers of mass to define the torsion angle are illustrated. The centers of mass of the switch or hinge regions are abbreviated with hh (hinge heavy) and hl (hinge light).