| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 2B04-CA-2 | CA | Ca²⁺ | K2 | LYS. | HOH.LYS. | ✔ | 2 | 4 | 2 | ✔ |
| 2B01-CA-2 | CA | Ca²⁺ | K2 | LYS. | HOH.LYS. | ✔ | 2 | 4 | 2 | ✘ |
| 2AZZ-CA-2 | CA | Ca²⁺ | K2 | LYS. | LYS. | ✔ | 2 | 2 | 2 | ✘ |