Postsynaptic neurotoxins, in this case erabutoxin b (PDB code
5ebx), are know to function by binding to the acetylcholine receptor.
This occurs through the mobile toxic loop. The residues forming
this loop are highlighted in the 3-D view and hence in the Contact
map. Looking at the B factor profiles for these residues indicates
a higher thermal motion at the tip region as one would expect.