Side view (backbone model)
A C-DOMAIN corresponds to the complete C-REGION, to most of the C-REGION, or to part of the C-REGION, depending on the immunoglobulin or T cell receptor chain type.
This figure shows the two associated C-DOMAINs of a gamma-delta T cell receptor gamma chain (PDB: 1hxm_B), delta chain (PDB: 1hxm_A). The two C-DOMAINs, C-GAMMA and C-DELTA are part of the TRG C-REGION and TRD C-REGION, respectively.
Only the C-DOMAINs are displayed. The carbohydrates are not shown.
In the PDB file, the sequences include 10 and 17 amino acids of the CONNECTING-REGION of the gamma and delta chains, respectively, however, the 3D structures only include amino acids up to positions 124 and 120, for the gamma and delta C-DOMAINs, respectively, according to the IMGT unique numbering for C-DOMAIN.
This image has been generated with the program RASMOL version 2.6  from the PDB file 1hxm , containing the atomic coordinates of the crystal structure of a human Vgamma9/Vdelta2 T cell receptor.
 Sayle, R. and Milner-White, E.J. TIBS, 20, 374 (1995).
 Allison, T.J. et al., Nature, 411, 820-824 (2001).