title: Analysis of two gene regions involved in the expression of the imipenem-specific, outer membrane porin protein OprD of Pseudomonas aeruginosa.
abstract: A Tn501 mutant of Pseudomonas aeruginosa resistant to imipenem and lacking the imipenem-specific outer membrane porin protein OprD was isolated. The mutation could be complemented to imipenem susceptibility and OprD-sufficiency by a cloned 6-kb EcoRI-PstI fragment of DNA from the region of chromosome of the wild-type strain surrounding the site of Tn501 insertion. However, this fragment did not contain the oprD structural gene as judged by its inability to hybridize with an oligonucleotide corresponding to the N-terminal amino acid sequence of OprD. DNA sequencing of 3.9 kb of the region surrounding the Tn501 insertion site revealed three large open reading frames, one of which would be interrupted by the Tn501 insertion in the mutant. This latter open reading frame, named opdE (for putative regulator of oprD expression), predicted a hydrophobic protein of M(r) 41,592. Using the above-mentioned oligonucleotide, the oprD structural gene was cloned and expressed in Escherichia coli on a 2.1-kb Bam HI-KpnI fragment. DNA sequencing predicted a 420 amino acid mature OprD protein with a 23 amino acid signal sequence.
authors.affiliation: Department of Microbiology, University of British Columbia, Vancouver, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Huang
authors.forename: R J
authors.initials: RJ
authors.lastname: Siehnel
authors.forename: F
authors.initials: F
authors.lastname: Bellido
authors.forename: E
authors.initials: E
authors.lastname: Rawling
authors.forename: R E
authors.initials: RE
authors.lastname: Hancock
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000235:genetics*; D015378:Imipenem; D008969:Molecular Sequence Data; D018272:Porins; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014162:Transfection / Q000235:genetics*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D018272:Porins; C077157:OprD protein, Pseudomonas aeruginosa; D015378:Imipenem