1 METABOLISM 
         1.01 amino-acid metabolism 
               1.01.01 amino-acid biosynthesis 
               1.01.04 regulation of amino-acid metabolism 
               1.01.10 amino-acid degradation (catabolism) 
               1.01.99 other amino-acid metabolism activities 
         1.02 nitrogen and sulphur metabolism 
               1.02.01 nitrogen and sulphur utilization 
               1.02.04 regulation of nitrogen and sulphur utilization 
               1.02.99 other nitrogen and sulphur metabolism activities 
          1.03 nucleotide metabolism 
               1.03.01 purine-ribonucleotide metabolism 
               1.03.04 pyrimidine-ribonucleotide metabolism 
               1.03.07 deoxyribonucleotide metabolism 
               1.03.10 metabolism of cyclic and unusual nucleotides 
               1.03.13 regulation of nucleotide metabolism 
               1.03.16 polynucleotide degradation 
                    1.03.16.01 RNA degradation 
               1.03.19 nucleotide transport 
               1.03.99 other nucleotide-metabolism activities 
          1.04 phosphate metabolism 
               1.04.01 phosphate utilization 
               1.04.04 regulation of phosphate utilization 
               1.04.07 phosphate transport 
               1.04.99 other phosphate metabolism activities 
          1.05 C-compound and carbohydrate metabolism 
               1.05.01 C-compound and carbohydrate utilization 
                    1.05.01.01 C-compound, carbohydrate catabolism 
                         1.05.01.01.01 sugar, glucoside, polyol and carboxylate catabolism 
                         1.05.01.01.03 C-2 compound, organic acid and fatty acid catabolism 
                    1.05.01.03 C-compound, carbohydrate anabolism 
                         1.05.01.03.02 polysaccharide biosynthesis 
                         1.05.01.03.04 aminosaccharide biosynthesis 
                    1.05.01.05 autotrophic CO2-fixation 
               1.05.04 regulation of C-compound and carbohydrate utilization 
               1.05.07 C-compound, carbohydrate transport 
               1.05.99 other carbohydrate metabolism activities 
          1.06 lipid, fatty-acid and isoprenoid metabolism 
               1.06.01 lipid, fatty-acid and isoprenoid biosynthesis 
                   1.06.01.01 phospholipid biosynthesis 
                   1.06.01.05 fatty acid biosynthesis 
                   1.06.01.07 isoprenoid biosynthesis 
                         1.06.01.07.11 tetracyclic and pentacyclic triterpenes (steroids and hopanoids) biosynthesis 
               1.06.04 breakdown of lipids, fatty acids and isoprenoids 
               1.06.07 lipid, fatty-acid and isoprenoid utilization 
               1.06.10 regulation of lipid, fatty-acid and isoprenoid biosynthesis 
               1.06.13 lipid and fatty-acid transport 
               1.06.99 other lipid, fatty-acid and isoprenoid metabolism activities 
          1.07 metabolism of vitamins, cofactors, and prosthetic groups 
               1.07.01 biosynthesis of vitamins, cofactors, and prosthetic groups 
               1.07.04 utilization of vitamins, cofactors, and prosthetic groups 
          1.20 secondary metabolism 
               1.20.01 metabolism of primary metabolic sugars derivatives 
                    1.20.01.01 biosynthesis of secondary monosaccharides 
                    1.20.01.07 biosynthesis of glycosides 
               1.20.13 biosynthesis of derivatives of homoisopentenyl pyrophosphate 
               1.20.15 biosynthesis of derivatives of dehydroquinic acid, shikimic acid and chorismic acid 
               1.20.17 biosynthesis of secondary products derived from primary amino acids 
               1.20.35.01 biosynthesis of stilbenes, flavonoids 
               1.20.37 biosynthesis of peptide derived compounds 
               1.20.99 other secondary metabolism activities 

     2 ENERGY 
          2.01 glycolysis and gluconeogenesis 
          2.07 pentose-phosphate pathway 
               2.07.01 pentose-phosphate pathway oxidative branch 
          2.10 tricarboxylic-acid pathway 
          2.11 electron transport and membrane-associated energy conservation 
               2.11.01 electron transport proteins 
               2.11.03 ATP synthesis proteins 
               2.11.05 accessory proteins of electron transport and membrane-associated energy conservation 
               2.11.99 other electron transport and membrane-associated energy conservation proteins 
          2.13 respiration 
               2.13.01 anaerobic respiration 
               2.13.05 aerobic respiration 
          2.16 fermentation 
               2.16.01 alcohol fermentation 
          2.19 metabolism of energy reserves (glycogen, trehalose) 
          2.22 glyoxylate cycle 
          2.25 oxidation of fatty acids 
          2.30 photosynthesis 
               2.30.01electron transport proteins of photosynthesis 
               2.30.03 accessory proteins of photosynthetic electron transport 
          2.99 other energy generation activities 

     3 CELL GROWTH, CELL DIVISION AND DNA SYNTHESIS 
          3.13 meiosis 
          3.16 DNA synthesis and replication 
          3.19 recombination and DNA repair 
          3.99 other cell growth, cell division and DNA synthesis activities 

     4 TRANSCRIPTION 
          4.01 rRNA transcription 
               4.01.01 rRNA synthesis 
               4.01.04 rRNA processing 
               4.01.99 other rRNA-transcription activities 
          4.03 tRNA transcription 
               4.03.01 tRNA synthesis 
               4.03.03 tRNA processing 
               4.03.06 tRNA modification 
               4.03.99 other tRNA-transcription activities 
          4.05 mRNA transcription 
               4.05.01 mRNA synthesis 
                    4.05.01.01 general transcription activities 
                    4.05.01.04 transcriptional control 
               4.05.03 mRNA processing (splicing) 
               4.05.05 mRNA processing (5'-, 3'-end processing, mRNA degradation) 
               4.05.99 other mRNA-transcription activities 
          4.99 other transcription activities 

    5 PROTEIN SYNTHESIS 
          5.01 ribosomal proteins 
          5.04 translation 
          5.07 translational control 
          5.10 tRNA-synthetases 
          5.99 other protein-synthesis activities 

     6 PROTEIN DESTINATION 
          6.01 protein folding and stabilization 
          6.04 protein targeting, sorting and translocation 6.07
          6.07 protein modification 
          6.10 assembly of protein complexes 
          6.13 proteolysis 
               6.13.01 cytoplasmic and nuclear degradation 
               6.13.04 lysosomal and vacuolar degradation 
               6.13.07 other proteolytic degradation 
          6.99 other protein-destination activities 

    7 TRANSPORT FACILITATION 
          7.01 channels/pores 
          7.04 ion transporters 
               7.04.01 metal ion transporters (Cu, Fe, etc.) 
               7.04.03 other cation transporters (Na, K, Ca , NH4, etc.) 
               7.04.99 anion transporters (Cl, SO4, PO4, etc.) 
          7.07 C-compound and carbohydrate transporters 
          7.22 transport ATPases 
          7.25 ABC transporters 
          7.99 other transport facilitators 

     8 CELLULAR TRANSPORT AND TRANSPORT MECHANISMS 
          8.01  nuclear transport 
          8.02 chloroplast transport 
          8.04 mitochondrial transport 
          8.07 vesicular transport (Golgi network, etc.) 
          8.10 peroxisomal transport 
          8.13 vacuolar transport 
          8.16 extracellular transport (secretion) 
          8.19 cellular import 
          8.22 cytoskeleton-dependent transport 
          8.99 other intracellular-transport activities 

    9 CELLULAR BIOGENESIS (proteins are not localized to the corresponding organelle) 
          9.01 biogenesis of cell wall (cell envelope) 
          9.03 biogenesis of plasma membrane 
          9.04 biogenesis of cytoskeleton 
          9.99 chloroplast biogenesis 

     10 CELLULAR COMMUNICATION/SIGNAL TRANSDUCTION 
         10.01 intracellular communication 
          10.03 unspecified signal transduction 
          10.05 receptor proteins 
          10.99 other unspecified signal transduction activities 

    11 CELL RESCUE, DEFENSE, CELL DEATH AND AGEING 
          11.01 stress response 
          11.03DNA repair 
               11.03.01nucleotide excision repair 
          11.05 Disease, virulence and defense 
               11.05.01 resistance proteins 
               11.05.03 defense related proteins 
               11.05.05 virulence, disease factors 
                     11.05.05.99   other virulence, disease factors 
               11.05.99 other disease and defense related proteins 
          11.07 detoxificaton 
               11.07.01 detoxification involving cytochrome P450 
               11.07.03 detoxification by modification 
               11.07.99 other detoxification 
          11.10 cell death and ageing
          11.10.09 degradation of exogenous ester compounds 
          11.99 other cell rescue activities 

    13  IONIC HOMEOSTASIS 
           13.04 ionic homeostasis

     30 CELLULAR ORGANIZATION (proteins are localized to the corresponding organelle) 
          30.01 organization of cell wall 
          30.02 organization of plasma membrane 
          30.03 organization of cytoplasm 
          30.04 organization of cytoskeleton 
          30.07 organization of endoplasmatic reticulum 
          30.08 organization of Golgi 
          30.09 organization of intracellular transport vesicles 
          30.10 nuclear organization 
          30.13 organization of chromosome structure 
          30.16 mitochondrial organization 
          30.19 peroxisomal organization 
          30.25 vacuolar and lysosomal organization 
          30.26 chloroplast organization 
          30.99 other cellular organization 

    98 CLASSIFICATION NOT YET CLEAR-CUT 

    99 UNCLASSIFIED PROTEINS