Figure 5. Deletion of MD motif 1 causes ClpB activation.
(A) Basal and substrate-stimulated ATPase activities of ClpB wild type and indicated MD deletions were determined in the absence and presence of casein. Relative ATPase activations by casein were calculated (inset). (B) Unfolding of Casein-YFP by BAP wild type and indicated MD deletions in the presence of ClpP was monitored by YFP fluorescence. Initial YFP fluorescence was set to 100%. ΔM1: ΔE410-Y455, ΔM2: ΔS456-E520, ΔM1/M2: ΔE410-E520. (C) E. coli ΔclpB cells expressing the indicated plasmid-encoded clpB alleles under control of an IPTG-regulatable promoter were grown overnight at 30°C. Various dilutions (10−1–10−7) were spotted on LB plates containing the indicated IPTG concentration and incubated at 37°C for 24 hr.