Figure 7.

ATPase activity of Spa47. Kinetics of ATP hydrolysis by various oligomeric forms of Spa47. The active oligomeric form (III) of Spa47 hydrolyzes ATP with a k _cat of 1.18 ± 0.03 s⁻¹, which is 8‐ to 10‐fold faster than the monomer and smaller oligomeric form (II) (k _cat = 0.15 ± 0.01 s⁻¹ and 0.11 ± 0.01 s⁻¹, respectively). All forms of the Spa47^K165A mutant protein are essentially inactive for ATP hydrolysis with k _cat values ≤0.03 ± 0.01 s⁻¹. Each data point represents the mean ± SD of three independent measurements from two separate protein preparations.