| C | Energy production and conversion | 15 | 15 | 15 |
| D | Cell cycle control, cell division, chromosome partitioning | 2 | 3 | 2 |
| E | Amino acid transport and metabolism | 16 | 16 | 16 |
| F | Nucleotide transport and metabolism | 19 | 19 | 19 |
| G | Carbohydrate transport and metabolism | 40 | 38 | 35 |
| H | Coenzyme transport and metabolism | 6 | 6 | 6 |
| I | Lipid transport and metabolism | 3 | 3 | 3 |
| J | Translation, ribosomal structure and biogenesis | 98 | 100 | 97 |
| K | Transcription | 7 | 7 | 7 |
| L | Replication, recombination and repair | 22 | 22 | 19 |
| M | Cell wall/membrane/envelope biogenesis | 3 | 3 | 3 |
| O | Posttranslational modification, protein turnover, chaperones | 10 | 10 | 10 |
| P | Inorganic ion transport and metabolism | 8 | 8 | 8 |
| R | General function prediction only | 11 | 10 | 10 |
| S | Function unknown | 1 | 1 | 1 |
| T | Signal transduction mechanisms | 3 | 3 | 3 |
| U | Intracellular trafficking, secretion, and vesicular transport | 5 | 5 | 4 |
| V | Defense mechanisms | 10 | 9 | 6 |
| X | Mobilome: prophages, transposons | 3 | 7 | 2 |
| — | Total in COG | 282 | 285 | 266 |