The Structures of the HC Fragment of Tetanus Toxin with Carbohydrate Subunit Complexes Provide Insight into Ganglioside Binding

The entry of tetanus neurotoxin into neuronal cells proceeds through the initial binding of the toxin to gangliosides on the cell surface. The carboxyl-terminal fragment of the heavy chain of tetanus neurotoxin contains the ganglioside-binding site, which has not yet been fully characterized. The crystal structures of native HC and of HC soaked with carbohydrates reveal a number of binding sites and provide insight into the possible mode of ganglioside binding.