Figure 7.

ATPase activity of WT RHAU and N-terminal mutants. (A) The extent of ATP hydrolysis by WT RHAU in the presence (open circle) or absence (filled circle) of poly(U) plotted as a function of input RHAU. The ATPase activity is expressed as a function of the activity obtained with WT RHAU at a concentration of 200 nM when poly(U) was omitted. (B) Influence of poly(U) on the ATPase activity of WT RHAU and DAIH ATPase-deficient mutant (200 nM). The ATPase activity was represented relatively to that of WT RHAU in the absence of poly(U) that was set to 1. (C) Influence of poly(U) on the ATPase activity of RHAU (WT) and ΔGly or ΔRSM RHAU mutants (200 nM). The basal ATPase activity (without nucleic acid co-factor) of WT RHAU is indicated (dashed line). The data represent the means ± SEM from three independent experiments.