Disease relevance of pykA

• In vitro enzyme analysis indicates that recombinant chlamydial enzymes expressed in E. coli are active and, interestingly, recombinant chlamydial pyruvate kinase is not regulated allosterically by fructose 1,6 bisphosphate or AMP, as found with other bacterial pyruvate kinases [1].
• Cloning and expression of the Zymomonas mobilis pyruvate kinase gene in Escherichia coli [2].
• The pyruvate kinase from Lactobacillus bulgaricus has been purified to homogeneity [3].

High impact information on pykA

• The modes of substrate binding have been deduced by analogy to D-Ala-D-Ala ligase and to pyruvate kinase [4].
• The reaction in which AP4 was formed was greatly stimulated by the addition of phosphoenolpyruvate plus pyruvate kinase and strongly inhibited by ADP and by CoA plus succinate [5].
• The mode of binding resembles closely the previously proposed PEP substrate binding mode, inferred by the homology of the structure (but not sequence homology) to pyruvate kinase [6].
• Frur mediates catabolite activation of pyruvate kinase (pykF) gene expression in Escherichia coli [7].
• We examined anaerobic E. coli cultures because of reports that in anaerobiosis, pyruvate kinase represents the major route for nucleoside triphosphate synthesis in the absence of nucleoside diphosphokinase [8].

Chemical compound and disease context of pykA

• Sequence comparison with E. coli type I, yeast and cat muscle pyruvate kinases shows that the binding regions of pyruvate kinase II are clearly divergent from those of pyruvate kinase I and of the eukaryotic enzymes [9].
• Fructose-1,6-bisphosphate-activated pyruvate kinase from Escherichia coli. Nature of bonds involved in the allosteric mechanism [10].
• The saturation of the pyruvate kinase from Lactobacillus bulgaricus is hyperbolic for ADP and cooperative for the other substrate phospho-enol-pyruvate [3].
• The allosteric properties of the fructose-1,6-bis-phosphate-activated pyruvate kinase from Escherichia coli were examined in the presence of a number of fructose bisphosphate analogues, as well as of increased ionic strength (NaCl) and of the hydrogen-bond-breaking agent, formamide [10].

Biological context of pykA

• The rate of hydrolysis was rather insensitive to the depletion of ADP in the assay medium by an ATP regenerating system (phospho-enol-pyruvate (PEP) and pyruvate kinase (PK)) [11].
• Citrate transport alters the intracellular balance of metal ions which in turn could trigger a sophisticated series of metabolic events leading to reduction of the activities of the pyruvate kinase and phosphofructokinase (PFK), the regulatory enzymes of glycolysis [12].

Associations of pykA with chemical compounds

• In the PTS- glucose+ host background, overexpression of tktA caused a further 3.7-fold increase in carbon flow, while inactivation of pykA and pykF caused a 5.8-fold increase [13].
• The activity of pyruvate kinase of Leishmania mexicana is allosterically regulated by fructose 2,6-bisphosphate (F-2,6-P(2)), contrary to the pyruvate kinases from other eukaryotes that are usually stimulated by fructose 1,6-bisphosphate (F-1,6-P(2)) [14].
• Pyruvate kinase is also weakly activated by AMP and inhibited by fructose-1,6-bisphosphate [3].

Analytical, diagnostic and therapeutic context of pykA

• The putative effector-binding site of Leishmania mexicana pyruvate kinase studied by site-directed mutagenesis [14].
• Molecular cloning of the genes for pyruvate kinase of two bacilli, Bacillus psychrophilus and Bacillus licheniformis, and comparison of the properties of the enzymes produced in Escherichia coli [15].

References