FIG 5.

BamA-BamD interactions coordinate BamA and BamD conformational changes during OMP assembly. (A) The wild-type Bam complex exists in an initial (tense) state that is competent to accept substrate and assemble OMPs. (B) Unfolded substrate arrives at the Bam complex and interacts with BamD and BamA. This interaction induces communication between BamA and BamD at POTRA5. (C) Proper binding of substrate by BamA and BamD triggers conformational changes that allow assembly to proceed. (D) Activated (relaxed) BamA and BamD can now continue to efficiently assemble OMPs into the outer membrane. (E) After OMP assembly, the Bam complex is recycled to its initial (tense) state.