Fig. 2.

Comparison of KIF17 and KIF3AB behavior under load. (A and B) Single-molecule (A) velocity and (B) randomness (solid circles; mean ± SE; $N=49–530$) measurements as a function of applied load for KIF17 (red) and KIF3AB (blue). Data were obtained in the presence of 2 mM ATP. (C and D) Single-molecule (C) velocity and (D) randomness (solid circles; mean ± SE; $N=22–319$) measurements as a function of ATP concentration for KIF17 (red) and KIF3AB (blue) under a constant load (legend). In all panels, solid lines represent global fits to the minimal four-state model (Fig. 3). Hindering-load and unloaded data for KIF3AB are reproduced from ref. 40.