FIG. 2.
Effect of the mxiM1 mutation on expression and secretion of IpaB and IpaC. Proteins in whole-cell extracts and culture supernatants of 2457T (wild-type), BS547 (mxiM1), BS576 (mxiM1/pBAD18), and BS548 (mxiM1/PBAD-mxiM+) were prepared, separated by SDS-PAGE, and subjected to immunoblot analysis. The positions of proteins that reacted with either IpaB or IpaC antiserum are shown. Differences in either IpaB or IpaC signal intensity among the whole-cell extract samples isolated from different strains are likely insignificant, as subsequent analyses showed nearly identical levels among the strains.