Structure of the Aeromonas toxin proaerolysin in its water-soluble and membrane-channel states.
Aerolysin is chiefly responsible for the pathogenicity of Aeromonas hydrophila, a bacterium associated with diarrhoeal diseases and deep wound infections. Like many other microbial toxins, the protein changes in a multistep process from a completely water-soluble form to produce a transmembrane channel that destroys sensitive cells by breaking their permeability barriers. Here we describe the structure of proaerolysin determined by X-ray crystallography at 2.8 A resolution. The protoxin (M(r) 52,000) adopts a novel protein fold. Images of an aerolysin oligomer derived from electron microscopy have assisted in constructing a model of the membrane channel and have led to the proposal of a scheme to account for insertion of the protein into lipid bilayers to form ion channels.
Parker
M W
MW
St Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.
Buckley
J T
JT
Postma
J P
JP
Tucker
A D
AD
Leonard
K
K
Pattus
F
F
Tsernoglou
D
D
D000333:Aeromonas / Q000737:chemistry*; D001427:Bacterial Toxins / Q000737:chemistry*; D003196:Computer Graphics; D018360:Crystallography, X-Ray; D007473:Ion Channels / Q000737:chemistry* / Q000648:ultrastructure; D008958:Models, Molecular; D052899:Pore Forming Cytotoxic Proteins; D011487:Protein Conformation; D011498:Protein Precursors / Q000737:chemistry* / Q000648:ultrastructure
D001427:Bacterial Toxins; D007473:Ion Channels; D052899:Pore Forming Cytotoxic Proteins; D011498:Protein Precursors; C032676:aerolysin