FIG. 3.

Analysis by immunoblotting of YopH expression by various Y. enterocolitica strains. Proteins isolated from culture supernatants and lysates of equal numbers of bacteria of pYV⁻ Y. enterocolitica, pYV⁺ Y. enterocolitica, or Y. enterocolitica W22703(pGC1152) YadA⁺ YopH⁻ were dissolved in SDS sample buffer, subjected to polyacrylamide gel electrophoresis, and transferred to nitrocellulose. YopH was detected by enhanced chemiluminescence immunodetection. Lines indicate positions of molecular mass markers (in kilodaltons). The major band of 45 kDa detected in the culture supernatant and lysate of pYV⁺ Y. enterocolitica corresponds to YopH. YopH was not detected in the culture supernatant and lysate of pYV⁻ Y. enterocolitica or Y. enterocolitica W22703(pGC1152) YadA⁺ YopH⁻. Recombinant YopH was used as a positive control. Data are representative of results from two independent experiments.