title: Identification and characterization of a new gene of Escherichia coli K-12 involved in outer membrane permeability.
abstract: Using a genetic selection for mutations which allow large maltodextrins to cross the outer membrane of Escherichia coli in the absence of the LamB maltoporin, we have obtained and characterized two mutations that define a new locus of E. coli. We have designated this locus imp for increased membrane permeability. Mapping studies show that the imp gene resides at approximately 1.2 min on the E. coli chromosome. The mutations alter the permeability of the outer membrane resulting in increased sensitivity to detergents, antibiotics and dyes. The mutations are nonreverting and codominant. Genetic analysis of the mutations suggest that the imp gene is an essential gene. We describe a general cloning strategy that can be used to clone both dominant and recessive alleles. Using this technique, we have cloned the wild-type and mutant imp alleles onto a low copy number plasmid.
authors.affiliation: Department of Biology, Princeton University, New Jersey 08544-1014.
authors.forename: B A
authors.initials: BA
authors.lastname: Sampson
authors.forename: R
authors.initials: R
authors.lastname: Misra
authors.forename: S A
authors.initials: SA
authors.lastname: Benson
mesh_terms: D000483:Alleles; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D002463:Cell Membrane Permeability; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D009154:Mutation; D010641:Phenotype; D010957:Plasmids; D011134:Polysaccharides / Q000493:pharmacokinetics; D018272:Porins; D015183:Restriction Mapping
chemical_list: D001425:Bacterial Outer Membrane Proteins; D011134:Polysaccharides; D018272:Porins; C008315:maltodextrin