Atom Nomenclature for TOP

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 TOP

Atom Name (V3) Atom Name (V2)
C1 C1
N2 N2
C3 C3
N4 N4
N5 N5
C6 C6
N7 N7
C8 C8
C9 C9
C10 C10
C11 C11
C12 C12
O13 O13
C14 C14
C15 C15
O16 O16
C17 C17
C18 C18
O19 O19
C20 C20
C21 C21
H1 H1
HN41 1HN4
HN42 2HN4
HN71 1HN7
HN72 2HN7
H91 1H9
H92 2H9
H11 H11
H141 1H14
H142 2H14
H143 3H14
H171 1H17
H172 2H17
H173 3H17
H201 1H20
H202 2H20
H203 3H20
H21 H21