Identification and characterization of the TonB region and its role in transferrin-mediated iron acquisition in Haemophilus parasuis.
Haemophilus parasuis is the causative agent of Glässer's disease, which is responsible for considerable economic losses in the pig-rearing industry. The aim of the study reported here was the identification, sequencing and molecular characterization of the TonB region that includes tonB, exbBD, and tbpBA genes in H. parasuis. In addition, two fusion proteins were generated. One of them (pGEX-6P-1-GST-TbpB) contained the first 501 amino acids of H. parasuis TbpB protein, while the second (pBAD-Thio-TbpB-V5-His) included the first 102 amino acids of H. parasuis TbpB N-terminus domain. A panel of 14 hybridomas secreting monoclonal antibodies was raised against the two recombinant TbpB fusion proteins. Furthermore, to assess whether the expression of the H. parasuis ExbB, TbpB, and TbpA proteins was upregulated under conditions of restricted availability of iron, a rabbit polyclonal antibody against H. parasuis TbpB-His fusion protein was produced. A rabbit polyclonal antibody against serotype 7 of Actinobacillus pleuropneumoniae ExbB and TbpA proteins was also used for the detection of the homologous proteins in H. parasuis. Overall, the data indicate that H. parasuis, like other members of the Pasteurellaceae family, possesses the genetic elements of the TonB region for iron acquisition and the transferrin-binding proteins encoded under this region are upregulated under restricted iron availability.
del Río
María Luisa
ML
Microbiology and Immunology Section, Department of Animal Health, School of Veterinary Medicine, University of Leon, Campus de Vegazana s/n, 24071 Leon, Spain.
Gutiérrez-Martín
César B
CB
Rodríguez-Barbosa
José I
JI
Navas
Jesús
J
Rodríguez-Ferri
Elías F
EF
D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics* / Q000276:immunology / Q000502:physiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D044137:Haemophilus parasuis / Q000235:genetics*; D015151:Immunoblotting; D007501:Iron / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics* / Q000276:immunology / Q000502:physiology; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014168:Transferrin / Q000378:metabolism*; D033881:Transferrin-Binding Protein A / Q000235:genetics; D033882:Transferrin-Binding Protein B / Q000235:genetics
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D014168:Transferrin; D033881:Transferrin-Binding Protein A; D033882:Transferrin-Binding Protein B; C057616:tonB protein, Bacteria; D007501:Iron