This technology includes a plasmid (designated pJH114) that encodes all five subunits of the E. coli Bam (barrel assembly machine) complex under the control of an inducible promoter to be used in the study of the Bam and screen for therapeutic small molecules. The Bam (barrel assembly machine) complex is a highly conserved heterooligomer that catalyzes the integration of membrane proteins that have a beta barrel structure into the outer membrane of Gram-negative bacteria. Research suggests that this complex is essential for the viability of most, if not all bacteria in this class. An octahistidine tag was added to one of the subunits (BamE) to facilitate purification. The plasmid can be used to direct the synthesis of large amounts of all of the subunits simultaneously in E. coli. We have found that the proteins produced by this plasmid assemble into highly active complexes that are easily purified.