| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 4D00-NI-1 | NI | Ni²⁺ | E2N1X1 | ASN.GLU.NAG. | ASN.GLU.NAG. | ✘ | 4 | 4 | 4 | ✔ |
| 4D00-NI-2 | NI | Ni²⁺ | E2N1X1 | ASN.GLU.NAG. | ASN.GLU.HOH.NAG. | ✘ | 4 | 5 | 4 | ✔ |
| 4D00-NI-3 | NI | Ni²⁺ | E2N1X1 | ASN.GLU.NAG. | ASN.GLU.NAG. | ✘ | 4 | 4 | 4 | ✔ |