A quantitative approach to catabolite repression in Escherichia coli.
A dynamic mathematical model was developed to describe the uptake of various carbohydrates (glucose, lactose, glycerol, sucrose, and galactose) in Escherichia coli. For validation a number of isogenic strains with defined mutations were used. By considering metabolic reactions as well as signal transduction processes influencing the relevant pathways, we were able to describe quantitatively the phenomenon of catabolite repression in E. coli. We verified model predictions by measuring time courses of several extra- and intracellular components such as glycolytic intermediates, EII-ACrr phosphorylation level, both LacZ and PtsG concentrations, and total cAMP concentrations under various growth conditions. The entire data base consists of 18 experiments performed with nine different strains. The model describes the expression of 17 key enzymes, 38 enzymatic reactions, and the dynamic behavior of more than 50 metabolites. The different phenomena affecting the phosphorylation level of EIIACrr, the key regulation molecule for inducer exclusion and catabolite repression in enteric bacteria, can now be explained quantitatively.
Bettenbrock
Katja
K
Systems Biology Group, Max-Planck-Institut für Dynamik komplexer technischer Systeme, 39106 Magdeburg, Germany. bettenbrock@mpi-magdeburg.mpg.de
Fischer
Sophia
S
Kremling
Andreas
A
Jahreis
Knut
K
Sauter
Thomas
T
Gilles
Ernst-Dieter
ED
D050260:Carbohydrate Metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism; D007700:Kinetics; D008954:Models, Biological; D009154:Mutation; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000378:metabolism; D010766:Phosphorylation; D015398:Signal Transduction
D029968:Escherichia coli Proteins; C032242:crr protein, E coli; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System