Fig. 3

ATPase activity of CtpB in the presence of heavy metal cations. The ATPase activity was measured using plasma membranes isolated from M. smegmatis mc²155 expressing CtpB (transformed with pALT10, black bars) and control cells (M. smegmatis transformed with pMV261, gray bars). The values of ATPase activity were measured separately by supplementing the enzymatic reactions with Co²⁺, Cu⁺, Cu²⁺, Mn²⁺, Ni²⁺, and Zn²⁺ (at 10 μM final concentration). The data correspond to the mean ATPases activity ± SEM derived from measurements of technical triplicates. Significant differences are values of **P ≤ 0.01