Overproduction of SecB does not cause significant effects on secretion and expression of Yops. Analogous to the experimental setup described in legend to Fig. 2, SecB was overproduced. (A) Coomassie-stained SDS-PAGE after loading of TCA-precipitated fractions of the culture supernatant. (B) Analysis of the corresponding cell lysates; Coomassie-stained gel (upper panel) and corresponding immunoblots to detect SecB, YopH, and YopE (lower panels).