title: Crystal structure of a cholera toxin-related heat-labile enterotoxin from E. coli.
abstract: 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.
authors.affiliation: BIOSON Research Institute, Groningen, The Netherlands.
authors.forename: T K
authors.initials: TK
authors.lastname: Sixma
authors.forename: S E
authors.initials: SE
authors.lastname: Pronk
authors.forename: K H
authors.initials: KH
authors.lastname: Kalk
authors.forename: E S
authors.initials: ES
authors.lastname: Wartna
authors.forename: B A
authors.initials: BA
authors.lastname: van Zanten
authors.forename: B
authors.initials: B
authors.lastname: Witholt
authors.forename: W G
authors.initials: WG
authors.lastname: Hol
mesh_terms: 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
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D005732:Gangliosides; D046911:Macromolecular Substances; D009243:NAD; C027538:heat-labile enterotoxin, E coli