Disease relevance of ppc

• The primary structure of phosphoenolpyruvate carboxylase of Escherichia coli. Nucleotide sequence of the ppc gene and deduced amino acid sequence [1].
• To investigate a possible chromosomal clustering of glycolytic enzyme genes in Corynebacterium glutamicum, a 6.4-kb DNA fragment located 5' adjacent to the structural phosphoenolpyruvate carboxylase (PEPCx) gene ppc was isolated [2].
• BamHI cleavage of DNAs from transducing phages gamma darg13 (ppc, argECBH, bfe), gamma darg14 (ppc, argECBH) and gamma darg23 (argECBH) yields three purely gamma DNA segments (and, in one case, a fourth), as well as several Excherichia coli-DNA-containing segments [3].

High impact information on ppc

• Before the elucidation of the three-dimensional structures of maize C4 leaf and Escherichia coli PEPC, our truncation analysis of the sorghum C4 homologue revealed important roles for the enzyme's C-terminal alpha-helix and its appended QNTG961 tetrapeptide in polypeptide stability and overall catalysis, respectively [4].
• Collectively, these functional and structural observations implicate the importance of the PEPC C-terminal tetrapeptide for both catalysis and negative allosteric regulation [4].
• We have now more finely dissected this element of PEPC structure-function by modification of the absolutely conserved C-terminal glycine of the sorghum C4 isoform by site-specific mutagenesis (G961(A/V/D)) and truncation (DeltaC1/C4) [4].
• The importance of the strictly conserved, C-terminal glycine residue in phosphoenolpyruvate carboxylase for overall catalysis: mutagenesis and truncation of GLY-961 in the sorghum C4 leaf isoform [4].
• Although the C4 polypeptide failed to accumulate in a PEPC- strain (XH11) of E. coli transformed with the Asp mutant, the other variants were produced at wild-type levels [4].

Chemical compound and disease context of ppc

• Plausible phosphoenolpyruvate binding site revealed by 2.6 A structure of Mn2+-bound phosphoenolpyruvate carboxylase from Escherichia coli [5].
• The transcriptional organization of the Corynebacterium glutamicum gap-pgk-tpi-ppc gene cluster, encoding glyceraldehyde-3-phosphate dehydrogenase, 3-phosphoglycerate kinase, triosephosphate isomerase, and phosphoenolpyruvate carboxylase, was investigated by Northern (RNA) blot and primer extension analyses [6].
• Two different forms of crystal for a phosphoenolpyruvate carboxylase from Escherichia coli were obtained by the hanging-drop vapor diffusion technique, using polyethylene glycol 4000 as precipitant [7].
• Fermentative production of succinic acid from glucose by Escherichia coli was significantly increased by overexpression of phosphoenolpyruvate carboxylase [8].
• Enhanced production of succinic acid by overexpression of phosphoenolpyruvate carboxylase in Escherichia coli [8].

Biological context of ppc

• The nucleotide sequence of the ppc gene, the structural gene for phosphoenolpyruvate carboxylase [EC 4.1.1.31], of Escherichia coli K-12 was determined [1].
• Knocking out ppc or gltA decreased the maximum cell density by 14% and increased the acetate excretion by 7%, respectively decreased it by 10% [9].
• The anaplerotic pathway catalyzed by malic enzyme was identified in the mutant, which was accompanied with an up-regulation of phosphoenolpyruvate carboxylase and down-regulation of phosphoenolpyruvate carboxykinase [10].
• These responses were abolished when either pck or ppc was deleted from the plasmid or when both enzymes were inactivated by mutation [11].
• These are gluconeogenesis, sfcA shunt, ppc shunt, glycogen biosynthesis, and fatty acid degradation [12].

Associations of ppc with chemical compounds

• Strain ALS961 (YYC202 ppc) prevented succinate accumulation, but growth was very poor [13].
• For example, the glucose transport genes (ptsHI, ptsG, crr) in both acetate and glycerol media were down-regulated, and the ppc, glycolytic, and biosynthetic genes in acetate were also down-regulated because of the reduced fluxes [14].
• The model study of Mn2+-bound PEPC complexed with phosphoenolpyruvate (PEP) reveals that the side chains of Arg-396, Arg-581 and Arg-713 could interact with PEP [5].
• In light of the important position of pyruvate at the juncture of NADH-generating pathways and NADH-dissimilating branches, the results show that when PPC or PYC is expressed, the metabolic network adapts by altering the flux to lactate and the molar ratio of ethanol to acetate formation [15].
• Histidine residues have previously been suggested to be essential for the activity of phosphoenolpyruvate carboxylase as demonstrated by chemical modification of these residues [16].

Other interactions of ppc

• Over-expression of ppc or gltA increased the maximum cell dry weight by 91% and 23%, respectively [9].
• The coordination sphere of Mn2+ observed in E. coli PEPC is similar to that of Mn2+ found in the pyruvate kinase structure [5].
• The nucleotide sequence of the ppc-argE intergenic region was also solved and shown to contain six tandemly repeated REP sequences [17].

Analytical, diagnostic and therapeutic context of ppc

• First crystallization of a phosphoenolpyruvate carboxylase from Escherichia coli [7].
• Site-directed mutagenesis of the conserved histidine residue of phosphoenolpyruvate carboxylase. His138 is essential for the second partial reaction [16].

References