FIG. 3.

Subcellular fractionation of B. suis VirB proteins produced in A. tumefaciens. Cells of UIA143 carrying pTrcB2-12, pTrcB1+3-12, and pTrcB3-12, respectively, were cultivated on AB minimal medium plates at 20°C for 3 days, followed cell lysis and membrane isolation. The protein content of subcellular fractions (total cell lysate [T], supernatant [S], and membrane fraction [M]) was analyzed by SDS-PAGE and Western blotting with B. suis VirB protein-specific antisera. Molecular masses of reference proteins are shown on the right.