Conformational changes among KIF5C–microtubule complexes. (A–D) Comparisons of positions of the tubulin monomers superimposed at α-tubulin on the right end. The translation vectors between Cα coordinate pairs are shown in black. The Cα chain trace model in each panel is KIF5C(PNP)–MT(GDP) (A, blue), KIF5C(ATP)–MT(GDP) (B, pink), KIF5C(ø)–MT(GDP) (C, green), and KIF5C(ø)–MT(GMPCPP) (D, orange). (C) KIF5C(ø)–MT(GDP) and KIF5C(ATP)–MT(GDP) adopt similar lattices. Movements of C domains are measured. (E) A GTP-like, high-affinity tubulin dimer will clash with the surrounding GDP-conformation tubulins. This shows that small amounts of KIF5C below the threshold cannot induce a conformational rearrangement of the GTP-like high-affinity microtubule. Blue, KIF5C(PNP)–MT(GDP); magenta, KIF5C(ø)–MT(GDP). Interatomic clashes and contacts were detected and colored in red using Chimera.