FIG. 1.

Steady-state amount of DnaK protein in E. coli cells expressing dnaK mutations in a ΔdnaK52 background. The ΔdnaK52 allele was transduced into strains GW8305, GW8309, TB1009, and TB1031. LB broth (5 ml) containing 0.5 mM IPTG, ampicillin, chloramphenicol, and kanamycin was inoculated with single-colony picks from these transductions and incubated at 30°C until cells reached an A₆₀₀ of 0.6. Cells were lysed by boiling in SDS-PAGE sample buffer, and equal amounts of protein from each cell lysate were loaded for SDS-PAGE. DnaK was detected by Western blot analysis using a polyclonal anti-DnaK antiserum and Western Light chemiluminescent detection (Tropix).