title: Functional expression of the glucose transporter of Zymomonas mobilis leads to restoration of glucose and fructose uptake in Escherichia coli mutants and provides evidence for its facilitator action.
abstract: The Zymomonas mobilis genes encoding the glucose facilitator (glf), glucokinase (glk), or fructokinase (frk) were cloned and expressed in a lacIq-Ptac system using Escherichia coli K-12 mutants deficient in uptake and phosphorylation of glucose and fructose. Growth on glucose or fructose was restored when the respective genes (glf-glk or glf-frk) were expressed. In E. coli glf+ strains, both glucose and fructose were taken up via facilitated diffusion (Km, 4.1 mM for glucose and 39 mM for fructose; Vmax at 15 degrees C, 75 and 93 nmol min-1 mg-1 [dry weight] for glucose and fructose, respectively). For both substrates, counterflow maxima were observed.
authors.affiliation: Institut für Biotechnologie, Forschungszentrum Jülich GmbH, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Weisser
authors.forename: R
authors.initials: R
authors.lastname: Krämer
authors.forename: H
authors.initials: H
authors.lastname: Sahm
authors.forename: G A
authors.initials: GA
authors.lastname: Sprenger
mesh_terms: D001483:Base Sequence; D001692:Biological Transport; D017931:DNA Primers / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism*; D005632:Fructose / Q000378:metabolism; D005816:Genetic Complementation Test; D005941:Glucokinase / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D017355:Zymomonas / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D009004:Monosaccharide Transport Proteins; D005632:Fructose; D005941:Glucokinase; D005947:Glucose