Open AccessFunctional 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
Author(s) -
Peter Weißer,
Reinhard Krämer,
Hermann Sahm,
Georg A. Sprenger
Publication year - 1995
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.177.11.3351-3354.1995
Subject(s) - zymomonas mobilis , fructokinase , fructose , biology , glucose transporter , glucokinase , escherichia coli , biochemistry , pep group translocation , major facilitator superfamily , mutant , levansucrase , glucose uptake , bacteria , insulin , enzyme , fermentation , gene , endocrinology , ethanol fuel , genetics , bacillus subtilis
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.