chapter  2
28 Pages

Three-Dimensional Protein Structures of Light Chains of Botulinum Neurotoxin Serotypes A, B, and E and Tetanus Neurotoxin

In the past few years, 21 botulinum neurotoxin (BoNT) protein structures and 8 tetanus neurotoxin (TeNT) structures have been deposited in the publicly accessible Protein Data Bank (PDB; Table 2.1). This represents structural information on serotypes A (BoNT/A) and B (BoNT/B) holotoxins (secreted forms of the neurotoxin with light chains (LC) in complex with heavy chains); LC structures of BoNT/A, /B, /E, and TeNT; and TeNT binding domain (C fragment). Given this wealth of structural information, it is exciting to see the insights gained regarding the toxins’ structures and functions, but interestingly, more questions than answers appear to have emerged with regards to toxin cell recognition, toxin translocation, and soluble N-ethyl-maleimide-sensitive fusion (NSF) protein attachment receptor (SNARE) proteolysis.