Protein complex which is involved in assembly and insertion of beta-barrel proteins into the outer membrane. In E. coli it is composed of BamABCDE, of the outer membrane protein BamA, and four lipoproteins BamB, BamC, BamD and BamE. BamA interacts directly with BamB and the BamCDE subcomplex. [ http://www.ncbi.nlm.nih.gov/pubmed/20378773 ]