title: VirG, a Yersinia enterocolitica lipoprotein involved in Ca2+ dependency, is related to exsB of Pseudomonas aeruginosa.
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.
authors.affiliation: Microbial Pathogenesis Unit, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Allaoui
authors.forename: R
authors.initials: R
authors.lastname: Scheen
authors.forename: C
authors.initials: C
authors.lastname: Lambert de Rouvroit
authors.forename: G R
authors.initials: GR
authors.lastname: Cornelis
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism*; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D008074:Lipoproteins / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010957:Plasmids / Q000235:genetics; D052899:Pore Forming Cytotoxic Proteins; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D014774:Virulence; D015008:Yersinia enterocolitica / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C095022:ExsB protein, Pseudomonas aeruginosa; C043908:LcrV protein, Yersinia; D008074:Lipoproteins; D052899:Pore Forming Cytotoxic Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C058483:virG protein, Shigella flexneri; D003545:Cysteine; D002118:Calcium