Fig. S6.

Illustration of allowed and forbidden rotations for dimeric tubulin. The insertion region (A₃₃₀–W₃₄₆) is colored according to chemical functionality (negative residues in red, positive residues in blue, and hydrophobic/aromatic in orange). The location of W346 is shown in a sphere mode. β-Tubulin monomer was placed using the 1TVK dimer and RMS orientation operation relative to the position of α-tubulin heavy atoms. The β-tubulin is shown as a magenta-colored ribbon. The following ranges of the two major Euler angles would result in a collision between β-tubulin and membrane bilayer: α from −35 to −45° and β from −10 to −20°.