FIGURE 5.

Inserting the Pf3-24C coat protein contacts YidC in the transmembrane residues of the outer leaflet. A, E. coli MK6 cells bearing the plasmid pMS-Pf3-24C and a second plasmid encoding the respective single cysteine YidC mutant were grown and treated as described in the legend to Fig. 2. Cross-links were detected by immunoprecipitations with an antibody to Pf3. For the control lanes, Pf3-28C and YidC505C (ctr) were coexpressed and treated as described above. The arrowheads depict the position of the YidC-Pf3 complex. B, positions of the Pf3-24C contacts with YidC in the six transmembrane segments. The residues that provided stable disulfide cross-links when mutated to a cysteine residue are shown in boldface. The contacts were found in the outer half of TM 3 and 5.