FIG. 3.

Deletion of ompU alters the growth and OM of a ΔepsE strain. (A) Strains O395 (●), KKV669 (▿), KKV780 (■), KKV884 (◊), KKV1234 (▴), and KKV1232 (○) were monitored for growth by measuring the OD₆₀₀. Strains were grown in LB medium at 37°C. (B) OM fractions were prepared (see Materials and Methods) from O395 (wild type, lane 1), KKV1234 (ΔepsE, lane 2), and KKV1232 (epsE ΔompU, lane 3). Samples were matched by equivalent OD₆₀₀ units, separated by SDS–10% PAGE, and stained with Coomassie blue. The mobilities of molecular mass markers are noted in kilodaltons on the left. The OM fractions were subjected to Western analysis as described in the text utilizing rabbit polyclonal antisera against OmpU (C) and V. cholerae OM (D) proteins that cross-reacted with OM protein bands at 35 and 28 kDa (12).