Figure 7.
Cryo-EM structure of the Cin8 motor domain bound to the canonical microtubule-binding site reveals novel loop 8 interaction with microtubule lattice. A, three-dimensional reconstruction of Cin8-His (light blue) in the ADP·AlFx state bound to the microtubule (gray) at ∼7 Å resolution. The loop 8 density is highlighted in red, and the difference in loop 5 conformation compared with the Eg5 model is indicated with an arrow. The crystal structure of Eg5 bound to AMPPNP (dark blue, PDB code 3HQD) was placed into the density by rigid docking. B, close-up view of loop 8 rotated 90° and looking into the loop, which makes contact with the microtubule lattice (red circle). C, average score (solid black line) for disorder prediction for the Cin8 motor domain plus the N-terminal extension (residues 1–535) based on eight different algorithms (see “Experimental procedures”). Gray zone shows calculated standard deviation of the mean at each residue. Vertical dotted lines show boundaries for the N terminus and the loop 8 insert.