Atom Nomenclature for IML

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 IML

Atom Name (V3) Atom Name (V2)
N N
CA CA
C C
O O
OXT OXT
CB CB
CN CN
CG2 CG2
CG1 CG1
CD1 CD1
H HN
HA HA
HXT HXT
HB HB
HN1 1HN
HN2 2HN
HN3 3HN
HG21 1HG2
HG22 2HG2
HG23 3HG2
HG12 1HG1
HG13 2HG1
HD11 1HD1
HD12 2HD1
HD13 3HD1