ATP hydrolysis by NcdY485 mutants.

<p>(A) Left, basal ATPase activity. Data points adjusted to OD₃₄₀ = 0.6531 (theoretical starting OD of NADH in reaction mix at t = 0) and fit to a line to determine rate of OD₃₄₀ decrease due to ATP hydrolysis. Right, microtubule-stimulated ATPase activity with 0.5 µM motor+1 µM microtubules. (B) NcdYK vs wild-type Ncd ATPase activity. <i>k_cat</i> (s⁻¹) per active site vs [MT]; 0.5 µM motor+0–25 µM microtubules (n = 3). Data points fit to the Michaelis-Menten equation to estimate <i>V_max</i> and <i>K_M,MT</i>. Mean±SEM.