Phosphoenolpyruvate carboxylase PPC

Also known as beta-alanine because of its similarity to the canonical amino acid L-lysine, it has been overproduced in E. coli. A strain was prepared, which included an aspartate decarboxylase gene panD) from C. glutamicum, overexpression of aspartase (aspA) and phosphoenolpyruvate carboxylase (ppc), and acetyl-CoA synthase (acs) and it resulted in total titers of 32 g 1 after 39 h from rich media supplemented by glucose and ammonium sulfate [61]. 

In addition, cyanobacteria possess a second carbon fixation mechanism through phosphoenolpyruvate carboxylase (PPC) that is responsible for close to 25% of CO2 fixation [102]. PPC fixes HCOg" rather than CO2 and combines it with phosphoenolpyruvate to form oxaloacetate and inorganic phosphate. An in silico modeling study has proposed to couple PPC with the core C4 plant carbon fixation cycle to Increase the overall carbon fixation rate compare to the CBB cycle [103]. 

Phosphoenolpyruvate carboxylase ppc Carboxylate phosphoenolpyruvate to form oxaloacetate... 

For the production of glutamic acid, anaplerotic reactions are important to supply oxaloacetate to the TC A cycle for the latter to proceed. C. glutamicum possesses the following two anaplerotic reactions, catalyzed by phosphoenolpyruvate carboxylase (PPC) and pyruvate carboxylase (PC) [63,64] ... 

Early attempts to increase SA production included the overexpression of the phosphoenolpyruvate carboxylase ppc, PEPC) and phosphoenolpyruvate carboxykinase ipck, PEPCK) genes, which are involved in CO2 fixation. These enzymes incorporate one molecule of CO2 to convert PEP into... 

Gene symbols are according to those of E. coli. (173). Abbreviations Horn, Homoserine Ant, Anthranilic acid PR, Phosphoribosyl ppc, Phosphoenolpyruvate carboxylase PRDH, prephenate dehydrogenase. 

Figure 15.3 3-Hydroxypropionate (3HP) synthesis via glycerol-dependent, malonyl-CoA-dependent, and p-alanine-dependent pathways. Gene symbols are ppc, phosphoenolpyruvate carboxylase aspC, aspartate...

Figure 11.5 Metabolic pathways related to glutamic acid production in C glutamicum. ICDH, isocitrate dehydrogenase, ODHC, 2-oxoglutarate dehydrogenase complex GDH, glutamate dehydrogenase PPC, phosphoenolpyruvate carboxylase and PC, pyruvate carboxylase.

PEP, phosphoenolpyruvate OAA, oxaloac-etate MAL, malate FUM, fumarate ICT, isocitrate CIT, citrate AcCoA, acetyl-CoA QOH, menaquinol GOX, glyoxylate aceA, isoci-tratelyase aceB, malate synthase pyc, pyruvate carboxylase ppc, phosphoenolpyruvate... 

Figure 19.2 Keto-add pathways for the production of n-butanol, isobutanol, and related compounds. Enzyme abbreviations Pyk, pyruvate kinase Ppc, phosphoenolpyruvate carboxylase AspC, aspartate aminotransferase ThrA, apartate kinase/homoserine dehydrogenase asd, aspartate semialdehyde dehydrogenase ThrB, homoserine kinase ThrC, threonine synthase LeuA, 2-isopropylmalate synthase LeuCD, 2-isopropylmalate hydrolyase/3-isopropylmalate...

Abbreviations NTP nucleotide triphosphate, PCK phosphoenolpyruvate carboxykinase, NDP nucleotide diphosphate, PEP phosphoenolpyruvate, PPC phosphoenolpyruvate carboxylase, OAA oxalacetic acid or oxalacetate and PYC pyruvate carboxylase... 

---