HEM
PCM
| Residue type | PCM type | Category | Position | UniProt PTM accession | Entries in PDB |
| ASP | None | Heme/heme-like | Amino-acid side chain (Any position) | 78 | |
| CYS | None | Heme/heme-like | Amino-acid side chain (Any position) | 210 | |
| CYS | None | Heme/heme-like | Amino-acid side chain (Any position) | 156 | |
| GLU | None | Heme/heme-like | Amino-acid side chain (Any position) | 76 | |
| GLU | None | Heme/heme-like | Amino-acid side chain (Any position) | 2 | |
| HIS | None | Heme/heme-like | Amino-acid side chain (Any position) | 1 | |
| MET | None | Heme/heme-like | Amino-acid side chain (Any position) | 49 | |
| ALA | None | Metal coordination | Amino-acid backbone (Any position) | 10 | |
| ARG | None | Metal coordination | Amino-acid side chain (Any position) | 1 | |
| CYS | None | Metal coordination | Amino-acid side chain (Any position) | 4500 | |
| DTR | None | Metal coordination | Amino-acid backbone (Any position) | 0 | |
| GLN | None | Metal coordination | Amino-acid side chain (Any position) | 1 | |
| GLU | None | Metal coordination | Amino-acid side chain (Any position) | 18 | |
| GLU | None | Metal coordination | Amino-acid side chain (Any position) | 8 | |
| GLY | None | Metal coordination | Amino-acid backbone (Any position) | 2 | |
| HIS | None | Metal coordination | Amino-acid side chain (Any position) | 9956 | |
| HIS | None | Metal coordination | Amino-acid side chain (Any position) | 6 | |
| LYS | None | Metal coordination | Amino-acid side chain (Any position) | 29 | |
| MET | None | Metal coordination | Amino-acid side chain (Any position) | 1191 | |
| MET | None | Metal coordination | Amino-acid backbone (Any position) | 1 | |
| MHS | None | Metal coordination | Amino-acid side chain (Any position) | 15 | |
| MSE | None | Metal coordination | Amino-acid side chain (Any position) | 4 | |
| PPI | None | Metal coordination | Amino-acid side chain (Any position) | 0 | |
| PRO | None | Metal coordination | Amino-acid backbone (Any position) | 6 | |
| SEC | None | Metal coordination | Amino-acid side chain (Any position) | 4 | |
| SER | None | Metal coordination | Amino-acid side chain (Any position) | 13 | |
| TRP | None | Metal coordination | Amino-acid side chain (Any position) | 2 | |
| TRP | None | Metal coordination | Amino-acid backbone (Any position) | 0 | |
| TYR | None | Metal coordination | Amino-acid side chain (Any position) | 627 | |
| TYR | None | Metal coordination | Amino-acid backbone (Any position) | 6 |
