Microtubule-stimulated ATPase activity of dynein ATP hydrolysis
mutants. A, microtubule-stimulated ATPase activity of wild type
and AAA mutants at 2 mm ATP. The insets show detailed
views of microtubule-stimulated ATPase activity at low microtubule
concentrations. Km,MT values for wild type
(WT), AAA3-E/Q, and AAA4-E/Q are 0.31, 0.03, and 0.069
μm. respectively. B, the ATP dependence of
microtubule-stimulated ATPase activity measured with 5 μm
taxol-stabilized microtubules. Insets show detailed views of the
curve at low ATP concentrations. Km,ATP values
for wild type, AAA3-E/Q, and AAA4-E/Q are 25.2, 24.6, and 24.7
μm, respectively. Each dot represents the mean ±
S.D. from three measurements of one preparation. Mean values from three
preparations are presented in Table
1.