FIGURE 3.

P_C/Q_D interaction identified by affinity chromatography and SPR experiments. A, batch co-purification of P_C and Q_D presented in this panel were performed on affinity columns. ^hisP_C and Q_D-N⁰¹²³ were mixed (upper panel) or loaded individually (lower panels) on an SDS-PAGE gel. Fractions L, FT, W1, W8, E1, and E2, respectively contain loaded protein, the flow-through, the washes, and the eluates. The positions of the molecular mass markers are indicated on the left side of each gel (kDa). B, the SPR sensorgram of the positive interaction found between ^hisP_C (bound ligand, underlined) and Q_D-N⁰¹²³ (analyte) (see ‘Experimental Procedures‘ for details). C–E, batch co-purification experiments of ^hisP_C and Q_D-N⁰¹² and ^hisP_C and Q_D-N⁰¹ and ^hisP_C and of minor pseudopilin soluble domains U_H, V_I, W_J, and X_K, respectively, on affinity columns.