FIGURE 6.

Dsb proteins influence ToxR inter‐ and intramolecular disulfide bond formation and its activity. V. cholerae strains harboring dsbA, dsbC and/or toxR mutations were grown in M9 maltose minimal medium until the mid‐log phase was reached. For ΔtoxRS strains carrying FLAGtoxRS on pBAD18‐Kan or pBAD18, samples were taken after 2 hr of induction with 0.1% arabinose when the cells reached the mid‐log phase. Immunoblotting was performed under standard non‐reducing Laemmli buffer conditions using anti‐ToxR (a) or anti‐FLAG antibodies (d); or reducing conditions using anti‐OmpU (b) or anti‐OmpT antibodies (c). (•) Represents nonspecific cross‐reacting background bands. It is to note, that Kang‐gel staining was performed to provide similar protein levels of all samples shown (Figure S6a,b). To note, all the characterized strains featured a chromosomally toxS⁺ background, except for the ΔtoxRS strain used