Figure 4.20 
The structure of a reverse turn. (A) The CO group of residue i of the polypeptide chain is hydrogen bonded to the NH group of residue i + 3 to stabilize the turn. (B) A part of an antibody molecule has surface loops (shown in red).
The structure of a reverse turn. (A) The CO group of residue i of the polypeptide chain is hydrogen bonded to the NH group of residue i + 3 to stabilize the turn. (B) A part of an antibody molecule has surface loops (shown in red).