FIGURE 6.

In vitro pull-down assay using NHS-activated Sepharose. Each panel shows the fraction containing all proteins eluted from the beads (Pull-down), as well as the purified protein tested for interaction with the beads (Prey). A, NHS-conjugated BceS (NHS-BceS) and the last washing step before elution (Wash) are also shown. The protein conjugated to the beads (Bait) is given below each panel. A and B, NHS-conjugated BceS incubated with purified BceAB (A) or BSA (B). C, NHS-conjugated BSA incubated with purified BceAB. D, NHS-Sepharose blocked with Tris and incubated with purified BceAB. BceAB eluting specifically from NHS-BceS beads is indicated by asterisk. Proteins were analyzed using SDS-PAGE, and gels were stained with Coomassie Brilliant Blue. A molecular size marker is indicated on the left in kDa, and the protein bands are labeled on the right.