| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 4US5-NA-1 | NA | Na⁺ | H1N1S1 | ASN.HIS.SER. | ASN.HIS.SER. | ✘ | 3 | 3 | 2 | ✔ |