Pull-down assays indicating interactions between COX, Surf1c and CtaG.

<p>Interactions between COX, Surf1c, CtaG and CtaA were assayed by immunoprecipitation and subsequent Western blot analysis. Solubilized membranes from untreated (top) or crosslinked cells (bottom), including WT and deletion strains FA2 (Δ<i>surf</i>1c) and MR31 (Δ<i>cta</i>DI/DII), were used for Co-IP experiments with protein A/G magnetic beads, as described in the experimental procedures. Eluates were separated by 12% SDS PAGE, blotted and probed against Surf1c, CtaA, COX SUI, COX SUII and CtaG. As bait antibody anti-COX (recognizing SUI and II), anti-CtaG, anti-Surf1c, anti-CtaA or a control serum was employed. The hashtag indicates a non-reproducible interaction and the asterisk designates unspecific staining (different molecular weight bands compared to control).