Atom Nomenclature for FTP

The atom nomenclature in PDB data files was revised with the release of data in the PDB Format Version 3.0. These changes make the PDB atom names used by PDB compliant with existing IUPAC nomenclature for standard amino acid and nucleotides (Pure & Appl. Chem., 70, 117-142, 1998) with the exception of the well established convention for C-terminal atoms OXT and HXT. A small number of additional changes were introduced in Version 3 to make atom labeling more conventional. The following chemical diagrams and tables provide the correspondences between atom names used in Version 3 and Version 2 PDB formats.

Labeled Chemical Diagrams

Chemical diagram with format V3 atom labels (heavy atoms)
Chemical diagram with format V3 atom labels (all atoms)
Chemical diagram with format V2 atom labels (heavy atoms)
Chemical diagram with format V2 atom labels (all atoms)

Atom Name Correspondences for FTP

Atom Name (V3) Atom Name (V2)
N1A N1A
C2A C2A
CM2 CM2
N3A N3A
C4A C4A
N4A N4A
C5A C5A
C6A C6A
C7A C7A
N3 N3
C2 C2
S1 S1
C5 C5
C4 C4
CM4 CM4
C6 C6
C7 C7
O7 O7
P1 P1
O1 O1
O2 O2
O3 O3
F1 F1
F2 F2
F3 F3
H4A1 1H4A
H4A2 2H4A
H6A1 1H6A
H7A1 1H7A
H7A2 2H7A
H21 1H2
HM41 1HM4
HM42 2HM4
HM43 3HM4
H61 1H6
H62 2H6
H71 1H7
H72 2H7