FIGURE 6.

NdhO blocks the interaction between NdhI and NdhK. GST pulldown assays show the interaction of NdhO with NdhI and NdhK (A) and NdhI with NdhK (B). The effect of NdhO on the interaction between NdhI and NdhK is shown (B). The expressed proteins were mixed and incubated with GST beads on a rotating shaker at 4 °C overnight. A, after washing, interaction of GST-NdhO with His-NdhI and His-NdhK was detected using the antibodies against NdhI and NdhK. The interactions of GST (without NdhO) with His-NdhI and His-NdhK and of pET32a vector backbone with GST-NdhO were used as negative controls. B, after washing, interaction between MBP-NdhI and GST-NdhK and the effect of His-NdhO on the interaction were detected using the antibody against NdhI. Protein blot against NdhO was used to indicate the additional amount of His-NdhO to the reaction system, while interactions of GST (without NdhK) with MBP-NdhI and MBP (without NdhI) with GST-NdhK were used as negative controls. Immunoblotting against a GST antibody was used to show the loading and binding control.