Figure 3.

Complementation of the trxA⁻, dipZ⁻, and dsbC⁻ mutations by addition of reduced DTT to the medium. Strains were grown to early logarithmic phase, labeled with [³⁵S]methionine for 30 sec, followed by a 1-min chase with unlabeled methionine at which point samples were removed and placed on ice in the presence of 100 mM iodoacetamide. Immunoprecipitation of alkaline phosphatase and gel electrophoresis were performed as described. Reduced DTT was added to the medium 5–10 min prior to labeling in the lanes designated with a +. In the lane designated red., the sample of the dsbC mutant that had not been treated with DTT during growth was reduced with 10 mM DTT at 80°C and alkylated with an excess of iodoacetamide at room temperature prior to loading on the gel.