Phosphotransferase system PTS

The Enzymes II (E-IIs) of the phosphoenolpyruvate (P-enolpyruvate)-dependent phosphotransferase system (PTS) are carbohydrate transporters found only in prokaryotes. They not only transport hexoses and hexitols, but also pentitols and disaccharides. The PTS substrates are listed in Table I. The abbreviations used (as superscripts) throughout the text for these substrates are as follows Bgl, jS-gluco-side Cel, cellobiose Fru, fructose Glc, glucose Gut, glucitol Lac, lactose Man, mannose Mtl, mannitol Nag, iV-acetylglucosamine Scr, sucrose Sor, sorbose Xtl, xylitol. 

The bacterial phosphoenolpyruvate (PEP)-dependent carbohydrate phosphotransferase systems (PTS) are characterised by their unique mechanism of group translocation. The transported solute is chemically modified (i.e. phos-phorylated) during the process (for comprehensive reviews see [151,152] and... 

Siebold, C., Flukiger, K., Beutler, R. and Emi, B. (2001). Carbohydrate transporters of the bacterial phosphoenolpyruvate sugar phosphotransferase system (PTS), FEBS Lett. 504, 104-111. 

Eukaryotic ABC transport system Phosphotransferase system (PTS) Ion-coupled transport system Signal Transduction Two-component system Bacterial chemotaxis MAPK signaling pathway Second messenger signaling pathway Ligand-Receptor Interaction G-protein-coupled receptors Ion-channel-linked receptors Cytokine receptors Molecular Assembly Ribosome assembly Flagellar assembly Enzyme assembly... 

Kok, M. Bron, G. Erni, B. Mukhija, S. Effect of enzyme I of the bacterial phosphoenolpyruvate sugar phosphotransferase system (PTS) on virulence in a murine model. Microbiology, 149, 2645-2652 (2003)... 

In E. coli, lactose is taken up by means of proton symport, maltose by means of a binding (ABC-type) protein-dependent system, melibiose by means of Na+ symport, and glucose by means of the phosphotransferase system (PTS). Although this bacterium normally does not transport sucrose, suppose that you isolated a strain that does. How do you determine whether one of the four mechanisms just listed is responsible for sucrose transport in this mutant strain ... 

The fructose released during this process (Fig. 15.9b-ii) binds to a glycan phosphotransferase system (PTS) of enzymes on the cell surface. This binding activates an enzyme on the cytosolic side of the PTS to attach a phosphate residue from phosphoenolpyruvate in the cytosol to a histidine residue of a PTS protein on the cytosoic side of the inner membrane. This activates the PTS enzyme system to transfer fructose 6-phosphate to the cytosol where it is phosphorylated and metabolized to lactate by glycolysis (Fig. 1.7). The PTS returns to its original conformation and another fructose molecule attaches and is transferred. The lactic acid is excreted, but trapped at the tooth surface by the glucan capsule. 

D-Fructose transport in micro-organisms, and the rapid utilization of D-fructose by bacteria is generally assumed to require the activity of a PEP (enol pyruvate phosphate)-dependent, phosphotransferase system (PTS).169 In this system, enzyme I catalyzes the transfer of phosphate from PEP to a nitrogen atom of a histidine residue in a small, high-energy protein, HPr, according to reaction I. In a subsequent step, enzyme II, in the presence of factor III, catalyzes the transfer of... 

Hiidig, H. Hengstenberg, W. The bacterial phosphoenolpyruvate dependent phosphotransferase system (PTS) solubilisation and kinetic para-... 

Excluding classical mutagenesis and selection on solid media, there are several reports on evolutionary engineering of simple cellular subsystems with an applied background. For example, experiments were performed with an E. coli strain that produced an aromatic compound and carried a deletion of the phosphotransferase system (PTS) for glucose uptake. Spontaneous glucose revertants were selected that apparently utilized a non-PTS system for glucose uptake... 

Figure 11.1 Proposed pathway for hex-ose metabolism of homofermentative LAB (1) and (2) phosphoenolpyruvate (PEP)-dependent sugar phosphotransferase system (PTS) (3) mannitol-specific PTS (4) phospho-glucose isomerase (5) mannitol-1-phosphate dehydrogenase (6) mannitol-1-phosphatase (7) 6-phosphofructokinase (8) fructose-diphosphatase (9) fructose-1,6-diphosphate aldolase (10) triosephosphate isomerase (11) glyceraldehyde-3-phosphate dehydrogenase...

However, the situations may become more sophisticated if uptake systems with stronger links to the nonlinear network dynamics are considered. The important example of the phosphoenol-dependendent phosphotransferase system (PTS) in Escherichia coli is discussed next to illustrate this level of complexity. The reaction scheme shown in Fig. 23 is responsible for the concomitant translocation and phosphorylation of several sugars across the cyto-plasmatic membrane. Sugar phosphorylation and translocation of glucose appears to involve several phosphoproteins, intermediates, and phosphoryl transfer reactions. 

Fig. 23. Reaction scheme of the phosphoenol-dependent phosphotransferase system (PTS) in Escherichia coli...

Several methods have been used for measuring the rate of sugar-P synthesized by specific kinases and ATP, or, by the phosphoenolpyruvateiglycose phosphotransferase system (PTS). Technically, the quantity of ADP produced by the kinase from ATP used as substrate was determined with P-enolpyruvate, pyruvate kinase, NADH, and lactate dehydrogenase. GlcN was omitted from... 

Microbes can normally utilize a variety of substrates for their growth and metabolism. Glucose is one of the carbon sources that can be firstly and rapidly assimilated and utilized by many microbes via the systems such as phosphotransferase system (PTS). When glucose exists as a substrate in a mixture with other carbons, it could inhibit the utilization of other carbon sources due to the presence of carbon catabolite repression (CCR) that is induced by the PTS global signal regulation. ... 

The pathways in the central carbon metabolism involve TCA cycle and glyoxylate shunt, glycolysis, phosphotransferase system (PTS), gluconeogenesis, pentose phosphate pathway (PPP).The carbon flux partitions at different nodes in the central metabolism and major flux partitioning for the product of interest may occur at principal branch points. Engineering of the enzymes in these branch points of the biosynthetic pathways will direct the carbon flux toward the product of interest leading to maximal product yield. 

Tanaka, Y., Teramoto, H., Inui, M., and Yukawa, H. (2008) Regulation of expression of general components of the phosphoenolpyruvate carbohydrate phosphotransferase system (PTS) by the global regulator SugR in Corynebacterium glutamicum. Appl. Microbiol. Biotechnol, 78 (2), 309—318. 

Figure 17.2 Anaerobic metabolic pathways involved in SA production in wild-type Anaerobiospirillum succiniciproducens. PEP, phosphoenolpyruvate OAA, oxaloacetate MAE, malate FUM, fumarate El, nonspecific protein of the phosphotransferase system (PTS) HPr, non-specific phosphoryl carrier protein of PTS pyk, pyruvate kinase pfo.

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