Table 2.

Motility parameters of heterodimeric KIF1A obtained by single-molecule assay

Motor	Velocity $\left(\mu \mathrm{m}{\mathrm{s}}^{-1}\right)$	Run length $\left(\mu \mathrm{m}\right)$	Run time $\left(\mathrm{s}\right)$
WT/V8M	$1.38\pm 0.62$	$10.2\pm 0.7$	$8.5\pm 0.6$
WT/R254Q	$1.35\pm 0.38$	$4.3\pm 0.4$	$3.1\pm 0.3$
WT/T258M	$1.08\pm 0.40$	$10.6\pm 0.8$	$9.7\pm 0.7$
WT/R350G	$1.61\pm 0.49$	$7.8\pm 0.6$	$5.1\pm 0.4$
V8M/R254Q	$1.12\pm 0.33$	$3.5\pm 0.2$	$3.5\pm 0.2$
V8M/T258M	$0.90\pm 0.27$	$9.6\pm 0.7$	$11.5\pm 0.8$
T258M/R254Q	$0.98\pm 0.25$	$3.8\pm 0.3$	$4.2\pm 0.3$
T258M/R350G	$1.19\pm 0.44$	$7.0\pm 0.7$	$6.3\pm 0.6$
R350G/V8M	$1.31\pm 0.50$	$8.2\pm 0.6$	$6.9\pm 0.4$
R350G/R254Q	$1.59\pm 0.41$	$3.0\pm 0.2$	$2.0\pm 0.1$

The velocities are mean $\pm$ SD. The run lengths and run times were determined by Eq. 13 after least-squares fittings of Eq. 12 to experimental data. The errors were estimated using bootstrapping.