| A | fn3 | e4bqbA1 | A: a/b three-layered sandwiches | X: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | H: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | T: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | F: fn3 | ECOD (v294.1) |
| A | DUF4982 | e4bqbA2 | A: a/b three-layered sandwiches | X: DP domain | H: DP domain | T: DP domain | F: DUF4982 | ECOD (v294.1) |
| B | fn3 | e4bqbB1 | A: a/b three-layered sandwiches | X: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | H: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | T: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | F: fn3 | ECOD (v294.1) |
| B | DUF4982 | e4bqbB2 | A: a/b three-layered sandwiches | X: DP domain | H: DP domain | T: DP domain | F: DUF4982 | ECOD (v294.1) |
| C | fn3 | e4bqbC1 | A: a/b three-layered sandwiches | X: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | H: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | T: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | F: fn3 | ECOD (v294.1) |
| C | DUF4982 | e4bqbC2 | A: a/b three-layered sandwiches | X: DP domain | H: DP domain | T: DP domain | F: DUF4982 | ECOD (v294.1) |
| D | fn3 | e4bqbD1 | A: a/b three-layered sandwiches | X: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | H: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | T: Fe-S cluster-binding domain in nickel-iron hydrogenase small subunit | F: fn3 | ECOD (v294.1) |
| D | DUF4982 | e4bqbD2 | A: a/b three-layered sandwiches | X: DP domain | H: DP domain | T: DP domain | F: DUF4982 | ECOD (v294.1) |