Atomic naming in PDB consists of 4 character field: atomic symbol (2 char), remoteness indicator (1 char), branch designator (1 char).
Remoteness indcator uses Greek letter distance abbreviation. In order of increasing distance, these are A for alpha, B for beta, G for gamma, D for delta, E for epsilon, Z for zeta, and H for eta.
Branch designator: digit designating the branch direction; left blank if the sidechain is unbranched.
Color scheme: Red=Oxygen; Gray=Carbon; Blue=Nitrogen; Cyan=Hydrogen; Yellow=Sulphur
| Ala | Cys | Asp | Glu |
 |  |  |  |
| Phe | Gly | His | Ile |
 |  |  |  |
| Lys | Leu | Met | Asn |
 |  |  |  |
| Pro | Gln | Arg | Ser |
 |  |  |  |
| Thr | Val | Trp | Tyr |
 |  |  |  |