Figure 2.

Structure of the C_H2 antibody domain and structural comparison with the corresponding region in the Fc and IgG structures.¹² (A) Ribbon diagram of the isolated, unglycosylated C_H2 domain from IgG g1 is shown. (B) The isolated C_H2 domain (green) was superimposed by a least-squares algorithm using the Cα traces of the C_H2 domains of Fc structure (blue; PDB code 2DTQ). (C) Superposition of the isolated C_H2 structure (green) with that of C_H2 portions of an intact IgG (PDB code 1HZH) using the Cα trace alignment. Heavy and light chains of IgG are shown in red and blue respectively. Carbohydrate moieties in between the C_H2 domains of Fc and IgG structures in (B) and (C) are omitted for clarity.