Figure 8.

Mutations that cause truncation of periplasmic domain of LapC induce transcription from the rpoEP3 promoter, which specifically responds to severe defects in LPS. Exponentially grown isogenic strains of the wild type and its derivatives with various lapC mutations as indicated, carrying the single-copy chromosomal rpoEP3-lacZ fusion, were analyzed for the β-galactosidase activity. Cultures were adjusted to an OD₅₉₅ of 0.05 and allowed to grow in LB medium at 30 °C. Aliquots of samples were drawn after different time intervals and used to measure the β-galactosidase activity. Error bars represent a S.E. of three independent measurements.