The document summarizes research on the minimal components required for the β-barrel assembly machinery (BAM) complex in E. coli. It finds that: 1) The minimal BAM complex that can be created in E. coli consists of BamA, BamC, and BamD proteins. 2) Loss of the BamB or BamE proteins can be compensated for by E. coli, but loss of BamC or BamD results in conditional lethality. 3) The research also analyzes mutants with changes to outer membrane proteins to study their effects on BAM complex assembly and function.