CRYSTALLIZATION OF THE B-CHAIN OF SHIGA-LIKE TOXIN-I FROM ESCHERICHIA-COLI

Shiga-like toxin I (SLT-I) is produced by several pathogenic strains of Escherichia coli associated with diarrheal disease. The toxin consists of an A chain, which attacks eukaryotic ribosomes, inhibiting protein synthesis, and multiple copies of a 69 ammo acid B chain. The B subunit mediates cell binding and uptake through its interactions with cell surface carbohydrate moieties. Here we report that the B chain has been crystallized in a form suitable for high-resolution X-ray analysis. The space group is P212121, with a = 56.2 A ̊, b = 59.9 A ̊ and c = 102.5 A ̊. A rotation function using three-dimensional diffraction data suggests that the asymmetric unit is a tetramer. © 1991.