| P12944 | n/a | 1frv | FEL | B | 537 | e1frvB3 | FAD-linked reductases, C-terminal domain-like | Ni-Fe binding domain in nickel-iron hydrogenase large subunit | Ni-Fe binding domain in nickel-iron hydrogenase large subunit | NiFeSe_Hases |
| P12944 | n/a | 1frv | FEL | B | 537 | e1frvB4 | FAD-linked reductases, C-terminal domain-like | Ni-Fe binding domain in nickel-iron hydrogenase large subunit | Ni-Fe binding domain in nickel-iron hydrogenase large subunit | NiFeSe_Hases |
| P12944 | n/a | 1frv | FEL | D | 537 | e1frvD3 | FAD-linked reductases, C-terminal domain-like | Ni-Fe binding domain in nickel-iron hydrogenase large subunit | Ni-Fe binding domain in nickel-iron hydrogenase large subunit | NiFeSe_Hases |
| P12944 | n/a | 1frv | FEL | D | 537 | e1frvD4 | FAD-linked reductases, C-terminal domain-like | Ni-Fe binding domain in nickel-iron hydrogenase large subunit | Ni-Fe binding domain in nickel-iron hydrogenase large subunit | NiFeSe_Hases |