Crystallization and preliminary X-ray analysis of tetanus neurotoxin C fragment

Two crystal forms of recombinant tetanus neurotoxin C fragment have been obtained. The C fragment corresponds to the C-terminal 451 amino-acid residues of tetanus neurotoxin and is the subunit responsible for receptor binding by the toxin. Both forms belong to space group P212121. Form I has unit-cell dimensions of a = 71.3, b = 79.7, c = 94.0 A and produces thin plate crystals. Form II has unit-cell dimensions of a = 67.4, b = 79.7, c = 91.1 A and produces thick rod-shaped crystals. Diffraction data to 2.6 A have been collected from form II crystals.