FIG. 7.

AgsA prevents heat-induced aggregation of proteins in the ΔdnaK52 mutant at 42°C. (A) ΔdnaK52 (strain BB1553) and ΔdnaK52 + pAgsA (strain CS5257) cells were grown in L medium that was either left unsupplemented (−) or supplemented with (+) 1 mM IPTG at 30°C for 2 h. Cells were cultured further at 42°C for 1 h. Aggregated proteins were isolated as described in Materials and Methods. Equal amounts of proteins (20 μg) were analyzed by SDS-15% PAGE. (B) The amount of aggregated protein was quantified by Bradford assay and calculated in relation to total protein content (set at 100%). Total, total cell lysate; Aggregated, aggregated proteins; M, molecular weight marker. Each value is the average from at least three different experiments.