FIG. 2.

20Map can replace the secretion signal of EspA. (A, top panel) Shown are comparable protein expression levels in whole-cell lysates of the different EPEC E2348/69 (E69) strains. (A, bottom panel) Native EspA is secreted from EPECΔespA (UMD872) but not from the escN, sepD, and sepL mutants, while 20Map-EspA is secreted from UMD872 and sepD and sepL mutants. Molecular mass markers (in kilodaltons) are indicated to the left. (B) 20Map-EspA is biologically active, as judged by its ability to complement an espA mutant in terms of actin polymerization at the bacterial attachment sites. Actin was labeled using Oregon Green-conjugated phalloidin.