Figure 2.

ATP-sensitive solubilization of the λ holin. S105 protein at 2 mg/mL in detergent was placed in dialysis chambers and dialyzed until visible precipitates formed. (A–C) Images of chambers after dialysis. In addition to the detergent-solubilized holin, the dialysis chambers contained (A,C) GroEL (1 mg/mL); (B) BSA (1 mg/mL). In C, the dialysis buffer contained 5 mM ATP. (D) S105 (100 μg/mL) dialyzed with GroEL (lanes 1,2), BSA (lanes 3,4), or GroEL + 5 mM ATP (lanes 5,6). Soluble and insoluble fractions obtained by centrifugation were analyzed by SDS-PAGE and immunoblotting with anti-S antibodies. Lanes 1, 3, 5 = supernatant (soluble fraction); 2, 4, 6 = pellet (insoluble fraction). Molecular masses as determined by mobility of standards are indicated. Monomer, dimer, trimer, and tetramer species of the holin are indicated by asterisks.