Table 3.

The Most Conserved Metabolic Pathways in E. coli Whose Enzymes Are Universally Present in the Three Domains of Life, Archaea (A), Bacteria (B) and Eucarya (E)

Pathway name Pathway superclass A-B-E A-B-E-Vr Enzymes Coverage
Tryptophan biosynthesisIndividual amino acids5051.00
Leucine biosynthesisIndividual amino acids6061.00
Arginine biosynthesis IIIndividual amino acids92111.00
Valine biosynthesisIndividual amino acids8090.89
Nonoxidative branch of the pentose phosphate pathwayEnergy-metabolism7080.88
Histidine biosynthesisIndividual amino acids7080.88
Purine biosynthesisPurines and pyrimidines120140.86
Enterobactin synthesisCofactor-biosynthesis5060.83
Riboflavin, FMN and FAD biosynthesisCofactor-biosynthesis5060.83
Threonine biosynthesisIndividual amino acids5060.83
FormylTHF biosynthesisIntermediary-metabolism72110.82
Methylglyoxal metabolismCentral-metabolism4050.80
Ribose catabolismCarbon-degradation4050.80
Thiamin biosynthesisCofactor-biosynthesis80100.80
Folic acid biosynthesisCofactor-biosynthesis71100.80
GluconeogenesisCentral-metabolism100130.77
Isoleucine biosynthesisIndividual amino acids100130.77
GlycolysisEnergy-metabolism100130.77
Aerobic respiration, electron donors reaction listEnergy-metabolism220290.76
Glyoxylate cycleEnergy-metabolism5070.71
Glycogen catabolismCarbon-degradation5070.71
Biosynthesis of proto- and sirohemeCofactor-biosynthesis70100.70
TCA cycle, aerobic respirationEnergy-metabolism140200.70

[i] Column names: Pathway name and superclass according to EcoCyc (Karp et al. 2000); ABE: number of enzymes in the three phylogenetic domains; ABEVr: number of enzymes in the three phylogenetic domains plus Viruses (Vr); Enzymes: total number of enzymes in the corresponding pathway; Coverage: ratio of the sum of universal enzymes over total, per pathway. Table is sorted by coverage.