Disease relevance of pfkA

• The elevated G + C content of Bs-pfk relative to the homologous Ec-pfkA from Escherichia coli is consistent with previous observations concerning genes from thermophilic prokaryotes [1].
• This interpretation is compatible with the known three-dimensional structure of another bacterial phosphofructokinase, that from Bacillus stearothermophilus [2].
• Cloning, sequencing, and expression of pyrophosphate-dependent phosphofructokinase from Propionibacterium freudenreichii [3].
• Kinetic and structural characterization of phosphofructokinase from Lactobacillus bulgaricus [4].
• Sequencing, cloning, and high-level expression of the pfp gene, encoding a PP(i)-dependent phosphofructokinase from the extremely thermophilic eubacterium Dictyoglomus thermophilum [5].

High impact information on pfkA

• Active-site mutants altering the cooperativity of E. coli phosphofructokinase [6].
• Phosphofructokinase in Escherichia coli is such an enzyme, being inhibited by phosphoenolpyruvate (PEP) and activated by ADP and GDP [7].
• We demonstrate here the essential function of an aspartate group in the catalysis of phosphoryl transfer by Escherichia coli phosphofructokinase, and the minor role of an arginine residue [8].
• Related sequences in both alpha and beta and in other enzymes that bind ATP or ADP in catalysis, notably myosin, phosphofructokinase, and adenylate kinase, help to identify regions contributing to an adenine nucleotide binding fold in both ATP synthase subunits [9].
• For growth, the assimilated fructose is sequentially phosphorylated by ATP and (i) manno(fructo)kinase, to form fructose 6-phosphate, and (ii) phosphofructokinase, to form fructose 1,6-bisphosphate, which is a member of central routes of glycolysis and gluconeogenesis [10].

Chemical compound and disease context of pfkA

• During the reaction catalyzed by the phosphofructokinase (EC 2.7.1.11) from Escherichia coli, the phosphoryl group transferred from ATP interacts with Thr-125 [Shirakihara, Y. & Evans, P. R. (1988) J. Mol. Biol. 204, 973-994] [11].
• Fructose 6-phosphate prevents the proteolyzed derivative of Escherichia coli phosphofructokinase from dissociation and inactivation [12].
• The leucine residue at position 178 in the allosteric phosphofructokinase from Escherichia coli has been changed into a tryptophan residue by oligonucleotide-directed mutagenesis [13].
• The allosteric phosphofructokinase from Escherichia coli has been renatured after complete unfolding in concentrated guanidine hydrochloride [2].
• Two instances, involving the enzymes carbamoyl-phosphate synthetase from Escherichia coli and phosphofructokinase from Bacillus stearothermophilus, respectively, are described in which increasing temperature alone causes the actions of an allosteric ligand to change from inhibition to activation [14].

Biological context of pfkA

• Mutations in the active site of Escherichia coli phosphofructokinase [8].
• Stopped-flow kinetics was utilized to determine how allosteric activators and inhibitors of wild-type Escherichia coli phosphofructokinase influenced the kinetic rate and equilibrium constants of the binding of substrate fructose 6-phosphate [15].
• The 2.8-kilobase cDNA was inserted in the plasmid vector pPL2 and transformed into Escherichia coli cells deficient in endogenous phosphofructokinase activity (DF 1020) [16].
• While showing no sequence identity to the non-allosteric ATP-dependent phosphofructokinase of E. coli, alignments of the amino acid sequence with other PFKs reveal degrees of identities among the amino halves of the proteins, from 26% between the Propionibacterium and potato PPi-PFKs, and 29% between Propionibacterium and E. coli ATP-PFKs [3].
• A gene encoding an ADP-dependent phosphofructokinase homologue has been identified in the hyperthermophilic archaeon Methanococcus jannaschii via genome sequencing [17].

Anatomical context of pfkA

• Folding and assembly of the alpha-subunit and beta-subunit of 6-phosphofructokinase were found to occur in the cell-free system resulting in an enzymatically active protein [18].

Associations of pfkA with chemical compounds

• The same changes, a saturation by fructose 6-phosphate that is no longer cooperative and an activity that is no longer inhibited by phosphoenolpyruvate, are observed with wild-type phosphofructokinase when adenosine 5'-[gamma-thio]triphosphate is used instead of ATP as the phosphoryl donor [11].
• These two perturbations of the ATP-Thr-125 interaction lead to the suppression of both the allosteric inhibition by phosphoenolpyruvate and the cooperativity of fructose-6-phosphate saturation, as if replacing the neutral oxygen of ATP by sulfur or removing the methyl group of Thr-125 had "locked" phosphofructokinase in its active conformation [11].
• The geometry of this ATP-Thr-125 interaction and/or the presence of the methyl group on the beta-carbon of Thr-125 are crucial for the regulatory properties of phosphofructokinase [11].
• Specific suppression of heterotropic interactions in phosphofructokinase by the mutation of leucine 178 into tryptophan [13].
• Its regulatory properties substitute for those lacking in the reversible nonregulated pyrophosphate-dependent phosphofructokinase in this variant of the Embden-Meyerhof-Parnas pathway [19].

Other interactions of pfkA

• ADP-dependent glucokinase/phosphofructokinase, a novel bifunctional enzyme from the hyperthermophilic archaeon Methanococcus jannaschii [17].

Analytical, diagnostic and therapeutic context of pfkA

• Conversion of allosteric inhibition to activation in phosphofructokinase by protein engineering [7].
• N-terminal sequence analysis shows that the limited proteolysis of Escherichia coli phosphofructokinase results in the removal of the 40-50 C-terminal residues of each chain [12].
• The influence of urea on the allosteric phosphofructokinase from Escherichia coli has been studied by measuring the changes in enzymatic activity, protein fluorescence, circular dichroism, and retention in size-exclusion chromatography [20].
• Dissection of the effector-binding site and complementation studies of Escherichia coli phosphofructokinase using site-directed mutagenesis [21].
• Phosphofructokinase was the main product, as determined by enzyme assay, immunoprecipitation and gel electrophoresis [22].

References