| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1RER-HO-1 | HO | Ho | D3 | ASP. | ASP. | ✔ | 3 | 3 | 3 | ✔ |
| 1RER-HO-2 | HO | Ho | D3 | ASP. | ASP. | ✔ | 3 | 3 | 3 | ✘ |
| 8D87-HO-1 | HO | Ho | D3 | ASP. | ASP. | ✔ | 3 | 3 | 3 | ✔ |