A. Cryo-EM reconstructions and fitted models for class 1 and class 2 resulting from 3D classification of the data. Class 1 is composed of 71.3% of all particles (left) and class 2 of 28.7% of all particles (right). The cryo-EM density map for both classes is shown as a semi-transparent surface with a fitted model as cartoon. Left: schematic of monomeric dynein construct, box indicates region that was resolved in the cryo-EM maps. 