Figure 2.

Geometric description of the parameters used to generate the helical models. Constraints and limits are given in §2 and Table 1 ▶. Parameters of the helices in the inner bundle are subscripted h1, while the parameters of the outer helical bundle are subscripted h2. (a) The first helix is rotated with Euler angles α_h1, β_h1 and γ_h1. The resulting new helix orientation is shown in a lighter shade of gray. (b) The second helix is rotated with Euler angles α_h2, β_h2 and γ_h2 and a distance from the protein symmetry axis r _h2. (c) α_b is the rotation of the outer helical bundle about the inner helical bundle.