| P09772 | NIFK_KLEPN | Klebsiella pneumoniae | nifK | Detail |
| P19067 | NIFK_SINFN | Sinorhizobium fredii (strain NBRC 101917 / NGR234) | nifK1 NGR_a01110 y4vM; nifK2 NGR_a00870 y4xC | Detail |
| P00468 | NIFK_NOSS1 | Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576) | nifK all1440 | Detail |
| S0E2Y2 | GA7_GIBF5 | Gibberella fujikuroi (strain CBS 195.34 / IMI 58289 / NRRL A-6831) (Bakanae and foot rot disease fungus) (Fusarium fujikuroi) | P450-3 FFUJ_14337 | Detail |
| P96692 | MHQN_BACSU | Bacillus subtilis (strain 168) | mhqN ydfN BSU05480 | Detail |
| Q9DBN4 | P33MX_MOUSE | Mus musculus (Mouse) | P33monox Kiaa1191 | Detail |
| P06662 | NIFD_ACIFR | Acidithiobacillus ferrooxidans (Thiobacillus ferrooxidans) | nifD | Detail |
| P06121 | NIFD_BRADU | Bradyrhizobium diazoefficiens (strain JCM 10833 / IAM 13628 / NBRC 14792 / USDA 110) | nifD blr1743 | Detail |
| P06120 | NIFD_BRASP | Bradyrhizobium sp. (strain ANU 289) | nifD | Detail |
| B3EH88 | NIFH_CHLL2 | Chlorobium limicola (strain DSM 245 / NBRC 103803 / 6330) | nifH Clim_0685 | Detail |