Catalytic unfolding by ClpX and ClpA. (A) GFP-SsrA (5 μM) was incubated in buffer containing ClpX, 5 mM ATP (plus regenerating system), and 10 μM GroEL-trap. ClpX concentrations were 0.2 (○), 0.5 (□), and 1 μM (⋄). (B) Catalytic unfolding of GFP-SsrA by ClpA. Conditions were the same as for A but 0.2 (○), 0.5 (□), and 1 μM (⋄) ClpA were used.