Disease relevance of virF

• virF-positive Yersinia pseudotuberculosis and Yersinia enterocolitica found in migratory birds in Sweden [1].
• Each ExsA-controlled promoter region contained at least two consensus sites in close proximity, similar to the arrangement of half-sites seen in AraC-controlled (Escherichia coli) or VirF-controlled (Yersinia enterocolitica) promoters [2].
• This 38-Kda mycobacterial protein designated as VirS exhibits homology with the VirF protein of Shigella, the VirFy protein of Yersinia and the Cfad, Rns and FapR proteins from various enterotoxigenic Escherichia coli strains [3].
• Thus, HrpX may regulate Xanthomonas virulence genes since a putative DNA binding domain present in the carboxyl terminal half of HrpX is highly conserved among HrpB, VirF and AraC and since over-expression of the carboxyl terminal half of HrpX in E. coli is lethal [4].

High impact information on virF

• Gene virF encodes a key transcriptional activator of the yop, yadA and ylpA genes [5].
• Role of the transcriptional activator, VirF, and temperature in the expression of the pYV plasmid genes of Yersinia enterocolitica [5].
• The transcription activator VirF is a member of a new family of regulators including those of the arabinose and rhamnose operons as well as a regulator of enteric colonization pili [6].
• Identification of DNA sequences recognized by VirF, the transcriptional activator of the Yersinia yop regulon [7].
• In this work, we determined the sequences of eight VirF-binding sites from four different genes, by DNase I or hydroxyl radical footprinting [7].

Biological context of virF

• The production of Yops is coordinately regulated by a 20-kb region of the plasmid referred to as the Ca2+ dependence region and containing at least four loci called virA, virB, virC, and virF [8].
• Primers based on the nucleotide sequence of the virF gene in the pYV plasmid and the chromosomal ail gene were used in polymerase chain reaction (PCR) amplifications to directly identify Yersinia enterocolitica in blood [9].
• All 30 isolates belonged to bioserotype 2/0:3 and carried the virF gene in the virulence plasmid [10].
• Role of the transcription activator virF and the histone-like protein YmoA in the thermoregulation of virulence functions in yersiniae [11].
• VirF and ExsA both contain carboxy-terminal domains with the helix-turn-helix motif of DNA-binding proteins [12].

Anatomical context of virF

• For identification of pathogenic Y. pseudotuberculosis, each isolate from the three sources (blood, ascitic fluid, and drinking water) was also analysed for the inv gene for Y. pseudotuberculosis and the virF gene for virulent plasmid by PCR [13].

Analytical, diagnostic and therapeutic context of virF

• Virulence-associated genes viz. ail, virF, inv, myfA, ystA, ystB, ystC, tccC, hreP, fepA, fepD, fes, ymoA and sat were studied in 81 clinical and nonclinical strains of Y. enterocolitica biovar 1A by PCR amplification [14].

References