Table 1. Cofactor usage in anaerobic and aerobic oxidoreductases.
| Cofactorsa | Cofactor occurrence (percentage) | |
| Anaerobic enzymes | Aerobic enzymes | |
| NAD(H)** | 70 (45.5%) | 12 (9.9%) |
| NADP(H) | 46 (29.9%) | 32 (26.4%) |
| NAD/P(H) | 20 (13.0%) | 15 (12.4%) |
| FAD | 15 (9.7%) | 22 (18.2%) |
| Ascorbate** | 0 (0.0%) | 8 (6.6%) |
| Fe-S | 8 (5.2%) | 9 (7.4%) |
| Iron** | 4 (2.6%) | 32 (26.4%) |
| Heme** | 2 (1.3%) | 32 (26.4%) |
| Molybdenum | 1 (0.6%) | 5 (4.1%) |
| Copper* | 0 (0.0%) | 6 (5.0%) |
a
derived from UniProt.
**: χ2 significance at P<0.01.
*: χ2 significance at P<0.05.