Data from chimeric constructs consisting of kinesin-2 heads fused to the kinesin-1 stalk (2 mM ATP).
(A) Load dependence of run length for 3A-KHC constructs with different neck-linker domains, along with 3B-KHC, color-coded as in panel B. Values at each force are mean ± s.e. of fit to exponential run length distributions. Run lengths as a function of force were fit to exponential functions; parameters are given in Table S4.(B). Inset: Expanded view of run lengths at non-zero loads.
(B) Load dependence of velocity, colored as shown (legend). Velocity data were fit using a 3-state model with a single force-dependent transition. Parameters are given in Table S3. A comparison between velocities and run lengths for homodimers with the native KIF3A/B stalk (KIF3A/A and KIF3B/B) and the kinesin-1 stalk (3A-KHC and 3B-KHC) is shown in Figure S5. The corresponding data for kinesin-1 with an extended neck linker are displayed in Figure S6 and Table S1