Source:http://linkedlifedata.com/resource/pubmed/id/11734000
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
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| pubmed:dateCreated |
2001-12-5
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| pubmed:databankReference | |
| pubmed:abstractText |
Exotoxin A of Pseudomonas aeruginosa asserts its cellular toxicity through ADP-ribosylation of translation elongation factor 2, predicated on binding to specific cell surface receptors and intracellular trafficking via a complex pathway that ultimately results in translocation of an enzymatic activity into the cytoplasm. In early work, the crystallographic structure of exotoxin A was determined to 3.0 A resolution, revealing a tertiary fold having three distinct structural domains; subsequent work has shown that the domains are individually responsible for the receptor binding (domain I), transmembrane targeting (domain II), and ADP-ribosyl transferase (domain III) activities, respectively. Here, we report the structures of wild-type and W281A mutant toxin proteins at pH 8.0, refined with data to 1.62 A and 1.45 A resolution, respectively. The refined models clarify several ionic interactions within structural domains I and II that may modulate an obligatory conformational change that is induced by low pH. Proteolytic cleavage by furin is also obligatory for toxicity; the W281A mutant protein is substantially more susceptible to cleavage than the wild-type toxin. The tertiary structures of the furin cleavage sites of the wild-type and W281 mutant toxins are similar; however, the mutant toxin has significantly higher B-factors around the cleavage site, suggesting that the greater susceptibility to furin cleavage is due to increased local disorder/flexibility at the site, rather than to differences in static tertiary structure. Comparison of the refined structures of full-length toxin, which lacks ADP-ribosyl transferase activity, to that of the enzymatic domain alone reveals a salt bridge between Arg467 of the catalytic domain and Glu348 of domain II that restrains the substrate binding cleft in a conformation that precludes NAD+ binding. The refined structures of exotoxin A provide precise models for the design and interpretation of further studies of the mechanism of intoxication.
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| pubmed:grant | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/ADP Ribose Transferases,
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Toxins,
http://linkedlifedata.com/resource/pubmed/chemical/Exotoxins,
http://linkedlifedata.com/resource/pubmed/chemical/Furin,
http://linkedlifedata.com/resource/pubmed/chemical/Ligands,
http://linkedlifedata.com/resource/pubmed/chemical/Subtilisins,
http://linkedlifedata.com/resource/pubmed/chemical/Virulence Factors,
http://linkedlifedata.com/resource/pubmed/chemical/toxA protein, Pseudomonas aeruginosa
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| pubmed:status |
MEDLINE
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| pubmed:month |
Dec
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| pubmed:issn |
0022-2836
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| pubmed:author | |
| pubmed:copyrightInfo |
Copyright 2001 Academic Press.
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| pubmed:issnType |
Print
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| pubmed:day |
7
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| pubmed:volume |
314
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
823-37
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| pubmed:dateRevised |
2008-11-21
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| pubmed:meshHeading |
pubmed-meshheading:11734000-ADP Ribose Transferases,
pubmed-meshheading:11734000-Amino Acid Sequence,
pubmed-meshheading:11734000-Bacterial Toxins,
pubmed-meshheading:11734000-Binding Sites,
pubmed-meshheading:11734000-Computer Simulation,
pubmed-meshheading:11734000-Crystallization,
pubmed-meshheading:11734000-Crystallography, X-Ray,
pubmed-meshheading:11734000-Exotoxins,
pubmed-meshheading:11734000-Furin,
pubmed-meshheading:11734000-Hydrogen Bonding,
pubmed-meshheading:11734000-Hydrogen-Ion Concentration,
pubmed-meshheading:11734000-Ligands,
pubmed-meshheading:11734000-Models, Molecular,
pubmed-meshheading:11734000-Mutation,
pubmed-meshheading:11734000-Pliability,
pubmed-meshheading:11734000-Protein Structure, Secondary,
pubmed-meshheading:11734000-Protein Structure, Tertiary,
pubmed-meshheading:11734000-Pseudomonas aeruginosa,
pubmed-meshheading:11734000-Sequence Alignment,
pubmed-meshheading:11734000-Static Electricity,
pubmed-meshheading:11734000-Structure-Activity Relationship,
pubmed-meshheading:11734000-Subtilisins,
pubmed-meshheading:11734000-Virulence Factors
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| pubmed:year |
2001
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| pubmed:articleTitle |
Refined crystallographic structure of Pseudomonas aeruginosa exotoxin A and its implications for the molecular mechanism of toxicity.
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| pubmed:affiliation |
Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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