Crystal structure of a cholera toxin-related heat-labile enterotoxin from E. coli.
Examination of the structure of Escherichia coli heat-labile enterotoxin in the AB5 complex at a resolution of 2.3A reveals that the doughnut-shaped B pentamer binds the enzymatic A subunit using a hairpin of the A2 fragment, through a highly charged central pore. Putative ganglioside GM1-binding sites on the B subunits are more than 20A removed from the membrane-crossing A1 subunit. This ADP-ribosylating (A1) fragment of the toxin has structural homology with the catalytic region of exotoxin A and hence also to diphtheria toxin.
Sixma
T K
TK
BIOSON Research Institute, Groningen, The Netherlands.
Pronk
S E
SE
Kalk
K H
KH
Wartna
E S
ES
van Zanten
B A
BA
Witholt
B
B
Hol
W G
WG
D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D003196:Computer Graphics; D003461:Crystallography; D004768:Enterotoxins / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D005732:Gangliosides / Q000378:metabolism; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism; D011487:Protein Conformation; D014961:X-Ray Diffraction
D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D005732:Gangliosides; D046911:Macromolecular Substances; D009243:NAD; C027538:heat-labile enterotoxin, E coli