Fig. 4.

Comparison of the interaction between purified N- and C-terminally Strep-tagged FocA derivatives and PflB. Purified N- or C-terminally Strep-tagged FocA (20 μg of protein) was incubated with the soluble fraction (1 mg of protein) derived from strains REK702 (increased FocA level) transformed with plasmid p29 and RM223 (ΔpflB ΔpflA ΔtdcE), which had been grown anaerobically (see Materials and Methods and Table S3). Equivalent amounts of suspension eluted from the matrix were separated by 10% (w/v) SDS-PAGE and challenged with antibodies directed against PflB. Size markers in kDa are shown on the left and the asterisk denotes the unidentified polypeptide that cross-reacts with the anti-PflB antibodies. (See also Fig. S1.)