Supplementary Figure 5
From: Direct induction of microtubule branching by microtubule nucleation factor SSNA1
(A) Gallery of electron micrographs of various CrSSNA1 truncation series tested for microtubule nucleation and branching. From left, observation of the purified protein at 0 h incubation (i.e. immediately after purification), 24 h incubation at RT, an overview after the addition of tubulin resulting in co-polymerized microtubules, and a magnified view of the copolymerized microtubules. Microtubule branching is shown with FL, 20-C and 1–105, while other protein fragments do not facilitate branching. For the proteins that do not cause the branching, examples of typical crossing of microtubules (red and blue bars at the scheme at the right column), instead of branching are shown. (B) Gallery of electron micrographs of various CrSSNA1 swap mutants. Left – all the mutants form cable-like fibrils. Right - branch formation is not induced with the E20K/D21K/K105E/K106E/K107E mutant. These images are representing three independent experiments.
