FIG. 1.

Expression of VirB6 in wild-type strain C58 and virB6 deletion strain CB1006. (A) Analysis of subcellular fractions from virulence gene-induced (+AS) or uninduced (−AS) strain C58 after SDS-PAGE and Western blotting with VirB6-specific antiserum. T, total cell lysate; S, soluble fraction; M, membrane proteins. (B) Analysis of cell lysates from wild-type C58 (lanes 1) and virB6 deletion strain CB1006 carrying cloning vector pTrc200 (lane 2), pTrcB6 (lanes 3), or pTrcTraD (lanes 4) grown in the absence of induction, in the presence of AS for virulence gene induction, or in the presence of AS and IPTG for simultaneous induction of the trc promoter. Cell lysates were subjected to SDS-PAGE followed by Western blotting and detection with VirB6-specific antiserum. Arrowhead indicates aggregates of VirB6 detected in overexpressing cells. Numbers on the right are molecular masses of reference proteins in kilodaltons.