| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 2FKH-CA-2 | CA | Ca²⁺ | C1D1Q1V1 | ASP.DC.GLN.VAL. | ASP.DC.GLN.HOH.VAL. | ✘ | 4 | 5 | 2 | ✘ |
| 2FKC-CA-2 | CA | Ca²⁺ | C1D1Q1V1 | ASP.DC.GLN.VAL. | ASP.DC.GLN.HOH.VAL. | ✘ | 4 | 5 | 2 | ✔ |