FIG. 6.

Localization of IalB to the B. bacilliformis inner membrane. (A) Proteins (2.5 μg/lane) were separated by SDS-PAGE (15 to 20% [wt/vol] gradient), and the gel was silver stained. IalB was found in the inner membrane fractions of JB584 (lane 3) and SC2 (lane 7), the parental and transcomplemented B. bacilliformis strains, respectively. IalB was absent from all outer membrane fractions and the inner membrane fraction of SC1, the ialB mutant strain. (B) Corresponding immunoblot reacted with polyclonal anti-IalB antibodies. IalB localized to the inner membrane fractions of JB584 and SC1 (lanes 3 and 7, respectively). IPTG-induced E. coli M15(pQIALB) cell lysate is provided as a control in lane 1.