1 : Amino acid biosynthesis
	1.1 : Aromatic amino acid family
	1.2 : Aspartate family
	1.3 : Glutamate family
	1.4 : Pyruvate family
	1.5 : Serine family
	1.6 : Histidine family
2 : Purines, pyrimidines, nucleosides, and nucleotides
	2.1 : 2'-Deoxyribonucleotide metabolism
	2.2 : Nucleotide and nucleoside interconversions
	2.3 : Purine ribonucleotide biosynthesis
	2.4 : Pyrimidine ribonucleotide biosynthesis
	2.5 : Salvage of nucleosides and nucleotides
	2.6 : Sugar-nucleotide biosynthesis and conversions
3 : Fatty acid and phospholipid metabolism
	3.1 : Biosynthesis
	3.2 : Degradation
4 : Biosynthesis of cofactors, prosthetic groups, and carriers
	4.1 : Biotin
	4.2 : Folic acid
	4.3 : Heme, porphyrin, and cobalamin
	4.4 : Lipoate
	4.5 : Menaquinone and ubiquinone
	4.6 : Molybdopterin
	4.7 : Pantothenate and coenzyme A
	4.8 : Pyridoxine
	4.9 : Riboflavin, FMN, and FAD
	4.10 : Glutathione and analogs
	4.11 : Thiamine
	4.12 : Pyridine nucleotides
	4.13 : Chlorophyll and bacteriochlorphyll
	4.14 : Siderophores
5 : Central intermediary metabolism
	5.1 : Amino sugars
	5.2 : One-carbon metabolism
	5.3 : Phosphorus compounds
	5.4 : Polyamine biosynthesis
	5.5 : Sulfur metabolism
	5.6 : Nitrogen fixation
	5.7 : Nitrogen metabolism
	5.8 : Electron carrier regeneration
6 : Energy metabolism
	6.1 : Aerobic
	6.2 : Amino acids and amines
	6.3 : Anaerobic
	6.4 : ATP-proton motive force interconversion
	6.5 : Electron transport
	6.6 : Entner-Doudoroff
	6.7 : Fermentation
	6.8 : Glycolysis/gluconeogenesis
	6.9 : Pentose phosphate pathway
	6.10 : Pyruvate dehydrogenase
	6.11 : Sugars
	6.12 : TCA cycle
	6.13 : Methanogenesis
	6.14 : Biosynthesis and degradation of polysaccharides
	6.15 : Photosynthesis
	6.16 : Chemoautotrophy
7 : Transport and binding proteins
	7.1 : Amino acids, peptides and amines
	7.2 : Anions
	7.3 : Carbohydrates, organic alcohols, and acids
	7.4 : Cations and iron carrying compounds
	7.5 : Nucleosides, purines and pyrimidines
	7.6 : Porins
	7.7 : Unknown substrate
8 : DNA metabolism
	8.1 : DNA replication, recombination, and repair
	8.2 : Restriction/modification
	8.3 : Degradation of DNA
	8.4 : Chromosome-associated proteins
9 : Transcription
	9.1 : Degradation of RNA
	9.2 : DNA-dependent RNA polymerase
	9.3 : Transcription factors
	9.4 : RNA processing
10 : Protein synthesis
	10.1 : tRNA aminoacylation
	10.2 : Ribosomal proteins: synthesis and modification
	10.3 : tRNA and rRNA base modification
	10.4 : Translation factors
11 : Protein fate
	11.1 : Protein and peptide secretion and trafficking
	11.2 : Protein modification and repair
	11.3 : Protein folding and stabilization
	11.4 : Degradation of proteins, peptides, and glycopeptides
12 : Regulatory functions
	12.1 : DNA interactions
	12.2 : RNA interactions
	12.3 : Protein interactions
	12.4 : Small molecule interactions
13 : Signal transduction
	13.1 : Two-component systems
	13.2 : PTS
14 : Cell envelope
	14.1 : Surface structures
	14.2 : Biosynthesis and degradation of murein sacculus and peptidoglycan
	14.3 : Biosynthesis and degradation of surface polysaccharides and lipopolysaccharides
15 : Cellular processes
	15.1 : Cell division
	15.2 : Chemotaxis and motility
	15.3 : Cell adhesion
	15.4 : Conjugation
	15.5 : Detoxification
	15.6 : DNA transformation
	15.7 : Sporulation and germination
	15.8 : Toxin production and resistance
	15.9 : Pathogenesis
	15.10 : Adaptations to atypical conditions
	15.11 : Biosynthesis of natural products
	15.12 : Bioluminescence
16 : Biological processes
	16.1 : Circulate
	16.2 : Construct biomass (Anabolism)
	16.3 : Control
	16.4 : Excrete
	16.5 : Explore
	16.6 : Maintain
	16.7 : Manage energy
	16.8 : Protect
	16.9 : Replicate
	16.10 : Respire
	16.11 : Scavenge (Catabolism)
	16.12 : Sense
	16.13 : Shape
	16.14 : Store
	16.15 : Symbiosis
17 : Mobile and extrachromosomal element functions
	17.1 : Plasmid functions
	17.2 : Prophage functions
	17.3 : Transposon functions
18 : Unknown function
	18.1 : Enzymes of unknown specificity
19 : Unclassified