Cloning of the protein D2 gene of Pseudomonas aeruginosa and its functional expression in the imipenem-resistant host.

Protein D2 forms the water-filled pore across the outer membrane of Pseudomonas aeruginosa and allows the penetration of imipenem. We cloned the protein D2 gene by the antibody screening technique. When the imipenem-resistant mutant lacking protein D2 harbored the plasmid with the cloned D2 gene, the mutant overproduced protein D2 in the outer membrane. These transformants exhibited fully-restored imipenem susceptibility. The results prove unequivocally that protein D2 forms the imipenem-permeable pore in the P. aeruginosa outer membrane.