Three-dimensional structure of cholera toxin penetrating a lipid membrane.
Two-dimensional crystals of cholera toxin bound to receptors in a lipid membrane give diffraction extending to 15 A resolution. Three-dimensional structure determination reveals a ring of five B subunits on the membrane surface, with one-third of the A subunit occupying the center of the ring. The remaining mass of the A subunit appears to penetrate the hydrophobic interior of the membrane. Cleavage of a disulfide bond in the A subunit, which activates the toxin, causes a major conformational change, with the A subunit mostly exiting from the B ring.
Ribi
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Department of Cell Biology, Howard Hughes Medical Institute, Stanford University School of Medicine, CA 94305.
Ludwig
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Mercer
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Schoolnik
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Kornberg
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D002772:Cholera Toxin; D005677:G(M1) Ganglioside; D008081:Liposomes; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008958:Models, Molecular; D010714:Phosphatidylethanolamines; D011487:Protein Conformation
D008081:Liposomes; D046911:Macromolecular Substances; D010714:Phosphatidylethanolamines; D005677:G(M1) Ganglioside; C020888:1,2-dielaidoylphosphatidylethanolamine; D002772:Cholera Toxin