Biomaterial Database

Control of glucose metabolism by the enzymes of the glucose phosphotransferase system in Salmonella typhimurium. 1995

J van der Vlag, and R van't Hof, and K van Dam, and P W Postma

E. C. Slater Instituut, University of Amsterdam, The Netherlands.

The quantitative role of the phosphoenolpyruvate:glucose phosphotransferase system (glucose phosphotransferase system) in glucose uptake and metabolism, and phosphotransferase-system-mediated regulation of glycerol uptake, was studied in vivo in Salmonella typhimurium. Expression plasmids were constructed which contained the genes encoding enzyme I (ptsI), HP (ptsH), IIAGlc (crr), and IICBGlc (ptsG) of the glucose phosphotransferase system behind inducible promoters. These plasmids allowed the controlled expression of each of the glucose phosphotransferase system proteins from about 30% to about 300% of its wild-type level. When enzyme I, HPr or IIAGlc were modulated between 30% and 300% of their wild-type value, hardly any effects on the growth rate on glucose, the glucose oxidation rate, the rate of methyl alpha-D-glucopyranoside (a glucose analog) uptake or the phosphotransferase-system-mediated inhibition of glycerol uptake by methyl alpha-D-glucopyranoside were observed. Employing the method of metabolic control analysis, it was shown that the enzyme flux control coefficients of these phosphotransferase system components on the different measured processes were close to zero. The enzyme flux control coefficient of IICBGlc on growth on glucose or glucose oxidation was also close to zero. In contrast, the enzyme flux control coefficient of IICBGlc on the flux through the glucose phosphotransferase system (transport and phosphorylation) was 0.72. The experimentally determined enzyme flux control coefficients allowed us to calculate the flux control coefficients of the phosphoenolpyruvate/pyruvate and methyl alpha-D-glucopyranoside/methyl alpha-D-glucopyranoside 6-phosphate couples and the process control coefficients of the phosphotransfer reactions of the glucose phosphotransferase system. We discuss the implications of these values and the possible control points in the glucose phosphotransferase system.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010731	Phosphoenolpyruvate Sugar Phosphotransferase System	The bacterial sugar phosphotransferase system (PTS) that catalyzes the transfer of the phosphoryl group from phosphoenolpyruvate to its sugar substrates (the PTS sugars) concomitant with the translocation of these sugars across the bacterial membrane. The phosphorylation of a given sugar requires four proteins, two general proteins, Enzyme I and HPr and a pair of sugar-specific proteins designated as the Enzyme II complex. The PTS has also been implicated in the induction of synthesis of some catabolic enzyme systems required for the utilization of sugars that are not substrates of the PTS as well as the regulation of the activity of ADENYLYL CYCLASES. EC 2.7.1.-.	Phosphoenolpyruvate Hexose Phosphotransferases,Phosphoenolpyruvate-Glycose Phosphotransferase System,Hexose Phosphotransferases, Phosphoenolpyruvate,Phosphoenolpyruvate Glycose Phosphotransferase System,Phosphotransferase System, Phosphoenolpyruvate-Glycose,Phosphotransferases, Phosphoenolpyruvate Hexose,System, Phosphoenolpyruvate-Glycose Phosphotransferase
D005947	Glucose	A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.	Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012486	Salmonella typhimurium	A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.	Salmonella typhimurium LT2
D017852	Phosphotransferases (Nitrogenous Group Acceptor)	A group of enzymes that catalyzes the transfer of a phosphate group onto a nitrogenous group acceptor. EC 2.7.3.