The levels of periplasmic chaperones and sigmaE response proteins in SurA and SurA strain complemented with SurA(23-28). In both a and b the values are shown relative to levels in SurA complemented with wild-type SurA. * indicates significant difference when >1.5 fold change and p < 0.05. (A two-sided two-sample t -test was used.) indicates not detected in the SurA strain.