Molecular cloning and characterization of the oprQ gene coding for outer membrane protein OprE3 of Pseudomonas aeruginosa

We cloned and characterized the oprQ gene coding for outer membrane protein OprE3 of Pseudomonas aeruginosa PAO1, The oprQ gene was composed of 1,275 base pairs including a sequence encoding for the signal sequence and a matu re protein with a Mr of 44,602. Computer-aided alignment and hydropathy ana lyses of the predicted amino acid sequences suggested that OprE3 is a trans membrane protein homologous to outer membrane proteins of P, aeruginosa suc h as OprD2 (OprD) porin and OprE1 (OprE) porin, Susceptibility to several a ntibiotics of the strains lacking or overproducing OprE3 was indistinguisha ble from that of the wild-type strain, suggesting that OprE3 is unlikely in volved in the diffusion of carbapenems and other beta-lactam antibiotics.