FIG. 3.

Effect of multicopy ibrAB on expression of chromosomally inserted single-copy eibF. Whole-cell extracts were fractionated on duplicate gels by SDS-10% PAGE. One gel was stained with Coomassie brilliant blue (A); the other was blotted to polyvinylidene difluoride and incubated with IgG Fc-HRP (B). Lane 1, single-copy eibF (CH7259); and lane 2, single-copy eibF with multicopy ibrAB (CH7259/pCS7067). Molecular mass standards are shown in the leftmost lanes in kilodaltons. The arrow indicates the most prominent band evident in lane 2 that is not present in lane 1.