Abstract
Hemolysin E (HlyE) is a novel pore-forming toxin of Escherichia coli, Salmonella typhi, and Shigella flexneri. Here we report the X-ray crystal structure of the water-soluble form of E. coli HlyE at 2.0 A resolution and the visualization of the lipid-associated form of the toxin in projection at low resolution by electron microscopy. The crystal structure reveals HlyE to be the first member of a new family of toxin structures, consisting of an elaborated helical bundle some 100 A long. The electron micrographs show how HlyE oligomerizes in the presence of lipid to form transmembrane pores. Taken together, the data from these two structural techniques allow us to propose a simple model for the structure of the pore and for membrane interaction.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Bacterial Proteins / chemistry*
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Bacterial Proteins / ultrastructure
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Bacterial Toxins / chemistry*
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Conserved Sequence
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Crystallography, X-Ray
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Escherichia coli / chemistry
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Escherichia coli Proteins*
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Hemolysin Proteins / chemistry*
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Hemolysin Proteins / ultrastructure
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Lipids / chemistry
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Membrane Proteins / chemistry
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Membrane Proteins / ultrastructure
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Microscopy, Electron
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Molecular Sequence Data
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Porins / chemistry*
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Porins / ultrastructure
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Protein Structure, Quaternary
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Protein Structure, Secondary
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Protein Structure, Tertiary
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Salmonella typhi / chemistry
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Sequence Homology, Amino Acid
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Shigella flexneri / chemistry
Substances
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Bacterial Proteins
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Bacterial Toxins
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Escherichia coli Proteins
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Hemolysin Proteins
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Hlya protein, E coli
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Lipids
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Membrane Proteins
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Porins
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hlyE protein, E coli