The putative molecular functions of 26,383 human genes (Venter et al., 2001)
| Number | % | |
|---|---|---|
| Enzyme | ||
| Hydrolase | 1,227 | 4.0 |
| Isomerase | 163 | 0.5 |
| Ligase | 56 | 0.2 |
| Lyase | 117 | 0.4 |
| Oxidoreductase | 656 | 2.1 |
| Synthase and synthetase | 313 | 1.0 |
| Transferase | 610 | 2.0 |
| Signal transduction | ||
| Select regulatory molecule | 988 | 3.2 |
| Kinase | 868 | 2.8 |
| Receptor | 1,543 | 5.0 |
| Signaling molecule | 376 | 1.2 |
| Nucleic acid binding | ||
| Nucleic acid enzyme | 2,308 | 7.5 |
| Transcription factor | 1,850 | 6.0 |
| None | ||
| Transfer/carrier protein | 203 | 0.7 |
| Viral protein | 100 | 0.3 |
| Miscellaneous | 1,318 | 4.3 |
| Cell adhesion | 577 | 1.9 |
| Chaperone | 159 | 0.5 |
| Cytoskeletal structural protein | 876 | 2.8 |
| Extracellular matrix | 437 | 1.4 |
| Immunoglobulin | 264 | 0.9 |
| Ion channel | 406 | 1.3 |
| Motor | 376 | 1.2 |
| Structural protein of muscle | 296 | 1.0 |
| Protooncogene | 902 | 2.9 |
| Select calcium binding protein | 34 | 0.1 |
| Intracellular transporter | 350 | 1.1 |
| Transporter | 533 | 1.7 |
| Molecular function unknown | 12,809 | 41.7 |
The functional predictions are based on similarity to sequences of known function.