The crystal structure of tetanus toxin Hc fragment complexed with a synthetic GT1b analogue suggests cross-linking between ganglioside receptors and the toxin

Tetanus toxin, a member of the family of Clostridial neurotoxins, is one of the most potent toxins known. The crystal structure of the complex of the COOH-terminal fragment of the heavy chain with an analogue of its gangliosi de receptor, GT1b, provides the first direct identification and characteriz ation of the ganglioside-binding sites. The ganglioside induces cross-linki ng by binding to two distinct sites on the Hc molecule. The structure sheds new light on the binding of Clostridial neurotoxins to receptors on neuron al cells and provides important information relevant to the design of antit etanus and anti-botulism therapeutic agents.