Figure 1.

Electron microscope images and their diffraction patterns. (A and B) Images of 15-protofilament brain microtubules decorated with the double-headed kinesin motor construct (KΔ430) and either treated with apyrase to remove all free nucleotide (A) or in the presence of ADP and hexokinase (B). Bar, 50 nm. (C and D) Computed Fourier transforms from A and B. The equatorial (eq.) and 8-nm layer lines are relatively weaker in patterns from an ADP-containing complex (D) than in those from the nucleotide-free state (C).