TABLE 3.

Extreme pathways in central metabolism^∗.

Pathway	Reaction
PPP (P84)	6PGn + 2G6P + 2GDP + 2H2O + 5NAD + + 4NADP + + Orthophosphate → 6PGL + 4CO2 + 2GTP + 9H + + 5NADH + 4NADPH + Pyr + Ru5P
EMP/GPL (P83)	2P + 2Acyl–CoA + CTP + 2G6P + 4GDP + NAD + + NADPH → 2CoA + Cytidine + 4GTP + H2O + NADH + NADP + + Orthophosphate + PGP + 2Pyr
pfkA (P34)	ATP + Orthophosphate → 2P + ADP
TCA (P46)	2ADP + FAD + 2Glu + 2H2O + 4NAD + + 2Orthophosphate + Quinone → 2ATP + 2Asp + FADH2 + 4H + + Hydroquinone + 4NADH
FA1 (P66)∗∗	8ATP + 2Acetyl–ACP + 18H + + 18HCO3– + 6NAD + + 26NADPH + 18Pyr → 18ADP + 36CO2 + 4FA_ex + 18H2O + 6NADH + 26NADP + + 18Orthophosphate
FA2 (P67)∗∗ EMP/GNG (P5)	2ACP + 18ATP + 16H + + 18HCO3– + 8NAD + + 26NADPH + 20Pyr → 18ADP + 38CO2 + 4FA_ex + 18H2O + 8NADH + 26NADP + + 18Orthophosphate 2P + G6P + 4GDP + 2NAD + + 2P + G6P + 2NAD + + Orthophosphate = 4GTP + 2H + 2H2O + 2NADH + 2Pyr

^∗PPP, pentose phosphate pathway; EMP/GPL, glycolysis and glycerophospholipid biosynthesis; pfkA, 6-phosphofructokinase 1 (pfkA_1, EC 2.7.1.11) and diphosphate-fructose-6-phosphate 1-phosphotransferase (pfkA_2, EC 2.7.1.90) formed cyclic pathway; TCA, tricarboxylic acid cycle; FA1 and FA2, both are fatty acid biosynthesis. EMP/GNG, glycolysis and gluconeogenesis. ^∗∗In fatty acid biosynthesis, FA1 utilizes 3-oxoacyl-ACP synthase II (FabF, CT_770, EC 2.3.1.179) on the step from malonyl-ACP to acetoacetyl-ACP, while FA2 use both FabF and 3-oxoacyl-ACP synthase III (FabH, CT_239, EC 2.3.1.180) for the same step. ACP, acyl carrier protein.