FIG. 4.

Delineation of the InvB-binding domain of SopE. Whole-cell lysates of Salmonella serovar Typhimurium ΔsopE strains carrying different plasmids expressing various segments of the amino terminus of SopE (residues 1 to 15, 1 to 38, 1 to 50, and 1 to 104) fused to PhoA, or whole-cell lysates of E. coli expressing carboxy-terminal domains of SopE (residues 78 to 240 and 115 to 240) fused to GST, were separated by SDS-PAGE and transferred to PVDF membranes. The blots were treated with a soluble lysate of E. coli expressing M45 epitope-tagged InvB, and the bound InvB-M45 was detected with a monoclonal antibody directed against M45 as previously described (upper panels) (2). To confirm the expression of the different constructs, the membranes were reprobed with antibodies directed against PhoA or GST (lower panels).