FIG 5.

CdiC promotes CdiA^STEC4 growth inhibition activity. (A) Inhibitor strains carrying the indicated cdiC alleles were cocultured at a 1:1 ratio with Δwzb target bacteria on agar media. Where indicated, inhibitor strains were complemented with wild-type cdiC integrated at the glmS locus. Competitive indices are the averages ± SEM from three independent experiments. (B) Alignment of CdiC^STEC4 with characterized RTX toxin-activating acyltransferases. Catalytic residues are highlighted in red. (C) E. coli strains expressing CdiA^STEC4 in the indicated cdiC backgrounds were incubated with IRDye680-maleimide, and urea-soluble protein was extracted for SDS-PAGE analysis and fluorimetry. Migration positions for full-length, ΔCT processed, and truncated CdiA^STEC4 are indicated. wt, wild type.