Fig. 2.

ATPase activity of the intact Lon-H₆ protease (A) and its deletion form Lon-dHI(CC) (B) in the absence (black columns) or presence (red columns) of the protein substrate, β-casein. Experimental conditions: 50 mM Tris- HCl buffer, pH 8.1; 0.15 M NaCl; 37°C; concentrations: 5 mM ATP; 20 (1, 2) or 5 mM (3, 4) MgCl₂; 0 (1, 3) or 0.5 mg/ml (2, 4) β-casein; 0.5-1.0 μM enzyme.