Figure 2.

(a) Overall structure of immunoglobulin G (PDB code; 1igt) is shown in a ribbon model. One light and two heavy chains are shown in beige, blue and cyan, respectively. Carbohydrate residues attached on the Fc region are shown in sphere models. (b) Close-up view of Asn297 attached glycan of human IgG1 Fc (PDB code; 2dts). Carbohydrate moiety and amino acid residues which interact with N-glycan are shown in the rod model. Hydrogen bonds between protein and carbohydrate are shown as red dotted lines.