J. T. Buckley

Crystallization of a proform of aerolysin, a hole-forming toxin from Aeromonas hydrophila

Crystals of proaerolysin, the precursor of the hole-forming toxin from Aeromonas hydrophila, have been obtained. The mature form of this protein binds to a receptor on mammalian cells, aggregates and forms 30 A holes in the membrane. The crystals are tetragonal, space group P4(3)2(1)2, a = b = 104.00 A, c = 222.0 A. They contain a dimer in the asymmetric unit and diffract to a resolution of 2.6 A.

Structure and Assembly of the Channel-Forming Aeromonas Toxin Aerolysin

Aeromonas hydrophila is a water-borne Gram-negative bacterium associated with gastroenteritis and opportunistic infections.1 The organism secretes a protein toxin called aerolysin that appears to be a major virulence factor of the bacterium.2 The toxin is synthesized as a preproprotein with a typical signal sequence that is removed during transit across the inner membrane of the Aeromonas bacterium.3 The protoxin then appears to fold and dimerize in the periplasm and leaves the cell in a separate step that requires a group of more than 14 genes of the General Secretory Pathway.4,5