Abstract
Pathogenic yersiniae require Ca2+ for growth at 37 degrees C. They harbor closely related plasmids of about 70 kb that are essential for virulence. At 37 degrees C and in the absence of Ca2+ ions, these plasmids cause a decrease in growth rate and the release of large amounts of proteins called Yops. Here we describe the virG gene of Yersinia enterocolitica; virG is located just upstream of the virF gene, which encodes the transcriptional activator of some plasmid virulence factors. Analysis of the VirG amino acid sequence suggested that virG encodes a lipoprotein, which was confirmed by [3H]palmitate labeling of VirG-PhoA fusion proteins. A nonpolar virG mutant was constructed and found to be Ca2+ independent for growth at 37 degrees C but to still secrete Yops. This phenotype was complemented by the introduction of a plasmid harboring an intact virG gene. VirG was found to be homologous to ExsB, a protein encoded by a Pseudomonas aeruginosa gene located in the locus controlling exoenzyme S synthesis. Interestingly, the exsA gene, located just downstream of exsB, is also homologous to virF.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Antigens, Bacterial / biosynthesis
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Antigens, Bacterial / genetics
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Bacterial Outer Membrane Proteins / biosynthesis
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Bacterial Outer Membrane Proteins / genetics
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Bacterial Proteins / biosynthesis
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Bacterial Proteins / genetics*
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Base Sequence
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Calcium / metabolism*
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Cysteine / genetics
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Cysteine / metabolism
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DNA-Binding Proteins / biosynthesis
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DNA-Binding Proteins / genetics*
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Gene Expression Regulation, Bacterial
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Lipoproteins / biosynthesis
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Lipoproteins / genetics*
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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Plasmids / genetics
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Pore Forming Cytotoxic Proteins
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Pseudomonas aeruginosa / genetics*
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Pseudomonas aeruginosa / metabolism
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Recombinant Fusion Proteins / biosynthesis
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Recombinant Fusion Proteins / genetics
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Sequence Homology, Amino Acid
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Transcription Factors / biosynthesis
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Transcription Factors / genetics*
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Virulence
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Yersinia enterocolitica / genetics*
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Yersinia enterocolitica / metabolism
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Yersinia enterocolitica / pathogenicity
Substances
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Antigens, Bacterial
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Bacterial Outer Membrane Proteins
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Bacterial Proteins
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DNA-Binding Proteins
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ExsB protein, Pseudomonas aeruginosa
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LcrV protein, Yersinia
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Lipoproteins
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Pore Forming Cytotoxic Proteins
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Recombinant Fusion Proteins
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Transcription Factors
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virG protein, Shigella flexneri
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Cysteine
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Calcium