Identification of TonB homologs in the family Enterobacteriaceae and evidence for conservation of TonB-dependent energy transduction complexes.

摘要: The transport of Fe(III)-siderophore complexes and vitamin B12 across the outer membrane Escherichia coli requires TonB-dependent energy transduction system. A set murine monoclonal antibodies (MAbs) was generated against an E. TrpC-TonB fusion protein to facilitate structure function studies. In present study, epitopes recognized by these MAbs were mapped, their distribution in gram-negative organisms examined. Cross-species reactivity patterns obtained TonB homologs known sequence used refine epitope mapping, with some ultimately confirmed inhibition experiments using synthetic polypeptides. Epitopes this conserved for 9 12 species family Enterobacteriaceae (including coli), including previously unidentified Shigella, Citrobacter, Proteus, Kluyvera species. These also detected a polyclonal alpha-TrpC-TonB serum that additionally Yersinia enterocolitica homolog putative Edwardsiella tarda. antibody preparations failed detect either Pseudomonas putida or Haemophilus influenzae but did identify potential several other nonenteric vivo chemical cross-linking demonstrated addition TonB, auxiliary components system are broadly members Enterobacteriaceae, suggesting represents common high-affinity active membrane.