Figure 2.

Filament growth of tightly bound protein in two dimensions. (A) initiation of filament growth in two dimensions two hours after GTP addition. (B) Sixty minutes later filaments have elongated in two preferential directions at approximately 60 degrees of each other. (C) One hour later, lateral addition of monomers has given rise to filament bundles. Time indicates minutes after GTP addition. (D,E) Zoom of two area shown in C to illustrate the diversity of angles and curvatures. Most of the angles are contained in a range between 85 and 35 degrees. White lines guide the eye to illustrate the range of angles and curvatures observed.