| Id | Element | Ion | Binding family | Amino acids or nucleotide residues names | All bound residues | Is homomer | Number of bound amino acids or nucleotide residues | Number of all bound residues | Number of coordinating chains | Representative |
|---|---|---|---|---|---|---|---|---|---|---|
| 3PNX-NA-1 | NA | Na⁺ | E3I1 | GLU.ILE. | GLU.HOH.ILE. | ✔ | 4 | 5 | 2 | ✔ |
| 3PNX-NA-3 | NA | Na⁺ | E3I1 | GLU.ILE. | GLU.HOH.ILE. | ✔ | 4 | 5 | 2 | ✔ |