title: Maltose and maltodextrin transport in Escherichia coli.
abstract: Escherichia coli K12 strains producing reduced amounts of LamB protein (one tenth the wild type amount) grow normally on dextrins but transport maltose at a concentration of 1 microM at about one tenth the normal rate. Dex--lamB missense mutants were found as derivatives of these strains. These Dex- mutants had a structurally altered LamB protein in the outer membrane, impaired in its interaction with phages lambda and K10, inefficient in maltose transport at low concentration (10 microM and below). The Dex- mutants still produced one tenth the wild type amount of the LamB protein as the parental Dex+ strains. Analysis of Dex+ revertants showed that the phenotype reverts to Dex+ when the altered LamB protein is made in wild type amounts. Even though they were Dex+, these revertants were still drastically altered in maltose transport at low concentration.
mesh_terms: D018528:ATP-Binding Cassette Transporters; D001425:Bacterial Outer Membrane Proteins; D001693:Biological Transport, Active; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003912:Dextrins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005947:Glucose / Q000378:metabolism; D008320:Maltose / Q000031:analogs & derivatives / Q000378:metabolism*; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D009154:Mutation; D011134:Polysaccharides / Q000378:metabolism*; D018272:Porins; D011991:Receptors, Virus / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D003912:Dextrins; D029968:Escherichia coli Proteins; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D011134:Polysaccharides; D018272:Porins; D011991:Receptors, Virus; C016532:maltoporins; C461599:maltose transport system, E coli; D008320:Maltose; C008315:maltodextrin; D005947:Glucose