| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 2POR-CA-1 | CA | Ca²⁺ | D1G1K1N2 | ASN.ASP.GLY.LYS. | ASN.ASP.GLY.HOH.LYS. | ✔ | 5 | 6 | 2 | ✔ |
| 2POR-CA-2 | CA | Ca²⁺ | D1G1K1N2 | ASN.ASP.GLY.LYS. | ASN.ASP.GLY.HOH.LYS. | ✔ | 5 | 6 | 2 | ✘ |
| 2POR-CA-3 | CA | Ca²⁺ | D1G1K1N2 | ASN.ASP.GLY.LYS. | ASN.ASP.GLY.HOH.LYS. | ✔ | 5 | 6 | 2 | ✘ |