Abstract
GtgE is an effector protein from Salmonella Typhimurium that modulates trafficking of the Salmonella-containing vacuole. It exerts its function by cleaving the Rab-family GTPases Rab29, Rab32 and Rab38, thereby preventing the delivery of antimicrobial factors to the bacteria-containing vacuole. Here, the crystal structure of GtgE at 1.65 Å resolution is presented, and structure-based mutagenesis and in vivo infection assays are used to identify its catalytic triad. A panel of cysteine protease inhibitors were examined and it was determined that N-ethylmaleimide, antipain and chymostatin inhibit GtgE activity in vitro. These findings provide the basis for the development of novel therapeutic strategies to combat Salmonella infections.
Keywords:
GtgE; Rab GTPase; Salmonella Typhi; Salmonella Typhimurium; cysteine proteases.
Publication types
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Research Support, American Recovery and Reinvestment Act
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Research Support, N.I.H., Extramural
MeSH terms
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Amino Acid Sequence
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Animals
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Bacterial Proteins / antagonists & inhibitors
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Bacterial Proteins / chemistry*
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism
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COS Cells
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Catalytic Domain
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Chlorocebus aethiops
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Crystallography, X-Ray
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Cysteine Proteinase Inhibitors / chemistry
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Escherichia coli / genetics
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Escherichia coli / metabolism
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Host Specificity
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Host-Pathogen Interactions
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Humans
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Models, Molecular
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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Protein Transport
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Proteolysis
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Salmonella typhimurium / chemistry*
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Salmonella typhimurium / enzymology
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Structure-Activity Relationship
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Vacuoles / metabolism
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rab GTP-Binding Proteins / chemistry*
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rab GTP-Binding Proteins / metabolism
Substances
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Bacterial Proteins
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Cysteine Proteinase Inhibitors
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Recombinant Proteins
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RAB38 protein, human
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rab GTP-Binding Proteins