Table 1. Conservation of residues important for calcium binding in the C-family of oxygen reductases and the cNOR and qNOR families of NO reductases.
The percent conservation of the residues is given, along with the variants for each family.
| Family | E1221 (in CcoN) Ca+2 ligand |
E1251 (in CcoN) | S1021 (in CcoO) Ca2+ ligand |
|---|---|---|---|
| C-family | E (Q) >99% | E (D, Q, K) 99% | S, T 100% (in CcoO) |
| cNOR | E (K, P, H, V, G) 85% | E (D) 95% | Y >99% (in NorC) |
| qNOR | E (A, S, D, P) 80% | D (E, S, Q, N, T) 45% | Y 90% |
1
The numbering of the residues refer to the cbb3 oxygen reductase from Pseudomonas stutzeri.