IG Domains and VH Domains

Again, superposition of these various domains (top) shows the amazing conservation of the basic folding pattern and the core positions.

On the other hand, superposion of members of one subclass of immunoglobulin domains, the variable domains of the immunoglobulin heavy chain (bottom) representing only two species, human and mouse represent a very wide range of different conformations particularely of the loop structures.