FIG 4.

Interaction of DctA with DctS using the mSPINE (A) and mHPINE (B) methods followed by Western blotting. DctS-Strep (DctS-S) and DctA-His (DctA-H) were coexpressed in E. coli C43(DE3), and the membranes were solubilized using 2% Empigen BB detergent. For the mSPINE assay, DctS-S was isolated from the solubilized membrane fraction using a Strep-Tactin column. As a control, DctA-H was expressed without DctS-S and the membrane fraction was applied to a Strep-Tactin column. For the mHPINE assay, DctA-H was isolated from the solubilized membrane fraction using a Ni-NTA column.