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Nature Chemical Biology Apr 2011
Topics: Animals; Biocompatible Materials; Calcium Carbonate; Decapoda; Materials Testing; Minerals; Phosphoenolpyruvate; Publications; Research
PubMed: 21423159
DOI: 10.1038/nchembio.550 -
Proceedings of the National Academy of... Oct 2006Bacterial transport of many sugars, coupled to their phosphorylation, is carried out by the phosphoenolpyruvate (PEP):sugar phosphotransferase system and involves five...
Bacterial transport of many sugars, coupled to their phosphorylation, is carried out by the phosphoenolpyruvate (PEP):sugar phosphotransferase system and involves five phosphoryl group transfer reactions. Sugar translocation initiates with the Mg(2+)-dependent phosphorylation of enzyme I (EI) by PEP. Crystals of Escherichia coli EI were obtained by mixing the protein with Mg(2+) and PEP, followed by oxalate, an EI inhibitor. The crystal structure reveals a dimeric protein where each subunit comprises three domains: a domain that binds the partner PEP:sugar phosphotransferase system protein, HPr; a domain that carries the phosphorylated histidine residue, His-189; and a PEP-binding domain. The PEP-binding site is occupied by Mg(2+) and oxalate, and the phosphorylated His-189 is in-line for phosphotransfer to/from the ligand. Thus, the structure represents an enzyme intermediate just after phosphotransfer from PEP and before a conformational transition that brings His-189 approximately P in proximity to the phosphoryl group acceptor, His-15 of HPr. A model of this conformational transition is proposed whereby swiveling around an alpha-helical linker disengages the His domain from the PEP-binding domain. Assuming that HPr binds to the HPr-binding domain as observed by NMR spectroscopy of an EI fragment, a rotation around two linker segments orients the His domain relative to the HPr-binding domain so that His-189 approximately P and His-15 are appropriately stationed for an in-line phosphotransfer reaction.
Topics: Binding Sites; Carbohydrate Metabolism; Crystallization; Crystallography, X-Ray; Dimerization; Escherichia coli; Histidine; Models, Molecular; Phosphoenolpyruvate; Phosphoenolpyruvate Sugar Phosphotransferase System; Phosphorylation; Phosphotransferases (Nitrogenous Group Acceptor); Protein Structure, Quaternary; Protein Structure, Tertiary
PubMed: 17053069
DOI: 10.1073/pnas.0607587103 -
Contributions To Microbiology 2009The PEP-dependent carbohydrate:phosphotransferase systems (PTSs) of enteric bacteria constitute a complex sensory system which involves as its central element a... (Review)
Review
The PEP-dependent carbohydrate:phosphotransferase systems (PTSs) of enteric bacteria constitute a complex sensory system which involves as its central element a PEP-dependent His-protein kinase (Enzyme I). As a unit, the PTS comprises up to 20 different transporters per cell which correspond to its chemoreceptors for PTS carbohydrates, and several targeting subunits, which include in the low [G+C] Gram-positive bacteria an ancillary Ser/Thr-protein kinase. The PTS senses the presence of carbohydrates, in particular glucose, in the medium and the energy state of the cell, in the form of either the intracellular PEP-to-pyruvate ratio or the D-fructose-bisphosphate levels. This information is subsequently communicated to cellular targets, in particular those involved in the chemotactic response of the cell towards PTS carbohydrates, and in sensing glucose in the medium, using cAMP and several targeting subunits as intermediates. Peptide targeting subunits ensure the fast, transient, and yet accurate communication of the PTS with its more than hundred different targets, avoiding at the same time unwanted cross-talk. Many elements of this sensory system are simultaneously elements of specific and global regulatory networks. Thus, the PTS controls, besides the immediate (in the ms to s range) chemotactic responses, the activity of the various carbohydrate transporters and enzymes involved in carbon and energy metabolism through inducer exclusion, and in a delayed response (in the min to h range) the synthesis of these transporters and catabolic enzymes through catabolite repression. Indirect consequences of this program are phenomena related to cell surface rearrangements, which include flagella synthesis, as well as memory, adaptation, and learning effects. The analogy between the PTS and other prokaryotic systems, and more complex sensory systems from eukaryotic organisms which share elements with regulatory systems is obvious.
Topics: Bacterial Physiological Phenomena; Biological Transport; Carbohydrate Metabolism; Chemotaxis; Computer Simulation; Glucose; Phosphoenolpyruvate; Phosphoenolpyruvate Sugar Phosphotransferase System; Pyruvic Acid; Quorum Sensing; Signal Transduction
PubMed: 19494579
DOI: 10.1159/000219373 -
Biochemistry Jan 2013A series of substrate analogues has been used to determine which chemical moieties of the substrate phosphoenolpyruvate (PEP) contribute to the allosteric inhibition of...
A series of substrate analogues has been used to determine which chemical moieties of the substrate phosphoenolpyruvate (PEP) contribute to the allosteric inhibition of rabbit muscle pyruvate kinase by phenylalanine. Replacing the carboxyl group of the substrate with a methyl alcohol or removing the phosphate altogether greatly reduces substrate affinity. However, removal of the carboxyl group is the only modification tested that removes the ability to allosterically reduce the level of Phe binding. From this, it can be concluded that the carboxyl group of PEP is responsible for energetic coupling with Phe binding in the allosteric sites.
Topics: Allosteric Regulation; Allosteric Site; Animals; Muscles; Phenylalanine; Phosphoenolpyruvate; Protein Binding; Pyruvate Kinase; Rabbits; Substrate Specificity
PubMed: 23256782
DOI: 10.1021/bi301628k -
Biochemical and Biophysical Research... May 1994Vanadate rapidly promotes the cleavage of phosphoenolpyruvate with phosphate liberation. This was not observed when ATP, glucose-6-phosphate and acetyl phosphate were...
Vanadate rapidly promotes the cleavage of phosphoenolpyruvate with phosphate liberation. This was not observed when ATP, glucose-6-phosphate and acetyl phosphate were incubated with vanadate. 51V NMR spectra shows that phosphoenolpyruvate and acetyl phosphate broadened and shifted upfield the monomeric vanadate signal at -561 ppm, indicative of vanadate/phosphate interactions. Comparatively, smaller changes were detected when glucose-6-phosphate was added to the vanadate solution. The shift behavior was not observed in the presence of ATP, ADP or pyruvate.
Topics: Adenine Nucleotides; Magnetic Resonance Spectroscopy; Phosphoenolpyruvate; Vanadates
PubMed: 8198568
DOI: 10.1006/bbrc.1994.1682 -
Biochimica Et Biophysica Acta May 1973
Topics: Adenosine Triphosphate; Animals; Biological Transport; Biological Transport, Active; Calcium; Glutamates; Glycosides; Kinetics; Malates; Mitochondria, Liver; Mitochondria, Muscle; Myocardium; Phenanthrenes; Phosphoenolpyruvate; Pyruvates; Rats; Rotenone; Spectrophotometry, Atomic; Time Factors
PubMed: 4718807
DOI: 10.1016/0005-2736(73)90304-0 -
FEBS Letters May 1978
Review
Topics: Animals; Bacteria; Liver; Oxaloacetates; Phosphoenolpyruvate; Pyruvate Carboxylase; Pyruvates; Saccharomyces cerevisiae; Species Specificity
PubMed: 350618
DOI: 10.1016/0014-5793(78)80510-9 -
FEMS Microbiology Reviews Sep 2005In many organisms, metabolite interconversion at the phosphoenolpyruvate (PEP)-pyruvate-oxaloacetate node involves a structurally entangled set of reactions that... (Review)
Review
In many organisms, metabolite interconversion at the phosphoenolpyruvate (PEP)-pyruvate-oxaloacetate node involves a structurally entangled set of reactions that interconnects the major pathways of carbon metabolism and thus, is responsible for the distribution of the carbon flux among catabolism, anabolism and energy supply of the cell. While sugar catabolism proceeds mainly via oxidative or non-oxidative decarboxylation of pyruvate to acetyl-CoA, anaplerosis and the initial steps of gluconeogenesis are accomplished by C3- (PEP- and/or pyruvate-) carboxylation and C4- (oxaloacetate- and/or malate-) decarboxylation, respectively. In contrast to the relatively uniform central metabolic pathways in bacteria, the set of enzymes at the PEP-pyruvate-oxaloacetate node represents a surprising diversity of reactions. Variable combinations are used in different bacteria and the question of the significance of all these reactions for growth and for biotechnological fermentation processes arises. This review summarizes what is known about the enzymes and the metabolic fluxes at the PEP-pyruvate-oxaloacetate node in bacteria, with a particular focus on the C3-carboxylation and C4-decarboxylation reactions in Escherichia coli, Bacillus subtilis and Corynebacterium glutamicum. We discuss the activities of the enzymes, their regulation and their specific contribution to growth under a given condition or to biotechnological metabolite production. The present knowledge unequivocally reveals the PEP-pyruvate-oxaloacetate nodes of bacteria to be a fascinating target of metabolic engineering in order to achieve optimized metabolite production.
Topics: Bacteria; Gene Expression Regulation, Bacterial; Glucose; Oxaloacetates; Pentose Phosphate Pathway; Phosphoenolpyruvate; Pyruvic Acid
PubMed: 16102602
DOI: 10.1016/j.femsre.2004.11.002 -
Archives of Biochemistry and Biophysics May 1990Purified phosphoenolpyruvate carboxylase from both the crassulacean acid metabolism plant Crassula argentea and the C4 plant Zea mays was shown by kinetic studies at... (Comparative Study)
Comparative Study
Purified phosphoenolpyruvate carboxylase from both the crassulacean acid metabolism plant Crassula argentea and the C4 plant Zea mays was shown by kinetic studies at saturating fixed-varying concentrations of free mg2+ to selectively use the metal-complexed form of phosphoenolpyruvate when assayed at pH 8.0. A similar response to added magnesium at high free phosphoenolpyruvate concentrations was obtained for both enzymes, consistent with the use of the complex as the substrate. Kinetic studies at pH 7.0 indicated that at this pH the total concentration of phosphoenolpyruvate (including both free and metal-complexed forms) could be used by the enzyme from C.argentea while the C4 enzyme still utilized the complex. The loss of specificity induced by the decrease in the pH of the assay medium was accompanied by a decrease in the Km of this enzyme for phosphoenolpyruvate whatever the form considered and an increase in Vmax/Km. In contrast, a similar decrease of pH led to an increased Km of the C4 enzyme for phosphoenolpyruvate and a decrease of Vmax/Km. For the enzyme from C. argentea (previously shown to contain an essential arginine at the active site), protection of activity by the different forms of substrate against inactivation by the specific arginyl reagent 2,3-butanedione changes markedly with pH. At pH 8.1, the metal complex is the better protector while at pH 7.0 free phosphoenolpyruvate gives the best protection consistent with the observed kinetic changes in substrate form utilization. The relationship between the enzyme affinity for substrate, substrate specificity, and the requirement for magnesium for substrate turnover is discussed.
Topics: Carboxy-Lyases; Hydrogen-Ion Concentration; Kinetics; Magnesium; Phosphoenolpyruvate; Phosphoenolpyruvate Carboxylase; Plants; Substrate Specificity; Zea mays
PubMed: 2327793
DOI: 10.1016/0003-9861(90)90272-z -
Biochemical and Biophysical Research... Jul 1984Mono- and bisphosphoglycerate competitively inhibited the transport of phosphoenolpyruvate across the erythrocyte membrane, although phosphoglycerates were impermeable...
Mono- and bisphosphoglycerate competitively inhibited the transport of phosphoenolpyruvate across the erythrocyte membrane, although phosphoglycerates were impermeable to the cell membrane. The Ki values of 2-phosphoglycerate, 3-phosphoglycerate and 2,3-bisphosphoglycerate were 8.8 mM, 10.4 mM and 4.3 mM, respectively, whereas glucose 6-phosphate had almost no effect on the transport of phosphoenolpyruvate.
Topics: 2,3-Diphosphoglycerate; Biological Transport; Diphosphoglyceric Acids; Erythrocyte Membrane; Glyceric Acids; Humans; Kinetics; Phosphoenolpyruvate
PubMed: 6466329
DOI: 10.1016/s0006-291x(84)80076-5