Figure 3.

The A, B, D and E strands of the CH3 dimer of IgG4, based on the crystal structure PDB1ADQ.⁶⁶ The start of the two A strands (Pro343) is indicated by the black and grey arrow for the first and second H-chain, respectively. In the figure on top left the CH2 domain is in the upward direction. The figure on the right shows the first view after 90° rotation on the horizontal axis, so it gives the view looking down from the CH2 domain on the CH3 domain. The figure on the bottom shows the first view after 90° rotation on the vertical axis. Note the stacked tyrosines (Y407) in the centre of the interface.