title: Campylobacter jejuni ferric-enterobactin receptor CfrA is TonB3 dependent and mediates iron acquisition from structurally different catechol siderophores.
abstract: Campylobacter jejuni NCTC11168 does not produce any endogenous siderophores of its own yet requires the CfrA enterobactin transporter for in vivo colonization. In addition, the genome of C. jejuni NCTC11168 contains three distinct TonB energy transduction systems, named TonB1, TonB2, and TonB3, that have not been tested for their role in siderophore uptake or their functional redundancy. We demonstrate that C. jejuni NCTC11168 transports ferric-enterobactin in an energy dependent manner that requires TonB3 for full activity with TonB1 showing partial functional redundancy. Moreover C. jejuni NCTC11168 can utilize a wide variety of structurally different catechol siderophores as sole iron sources during growth. This growth is solely dependent on the CfrA enterobactin transporter and highlights the wide range of substrates that this transporter can recognize. TonB3 is also required for growth on most catechol siderophores. Furthermore, either TonB1 or TonB3 is sufficient for growth on hemin or hemoglobin as a sole iron source demonstrating functional redundancy between TonB1 and TonB3. In vivo colonization assays with isogenic deletion mutants revealed that both TonB1 and TonB3 are required for chick colonization with TonB2 dispensable in this model. These results further highlight the importance of iron transport for efficient C. jejuni colonization.
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
authors.forename: Hemant
authors.initials: H
authors.lastname: Naikare
authors.forename: James
authors.initials: J
authors.lastname: Butcher
authors.forename: Annika
authors.initials: A
authors.lastname: Flint
authors.forename: Jide
authors.initials: J
authors.lastname: Xu
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Raymond
authors.forename: Alain
authors.initials: A
authors.lastname: Stintzi
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D016123:Campylobacter jejuni / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry*; D002396:Catechols / Q000737:chemistry*; D002417:Cattle; D002645:Chickens; D004758:Enterobactin / Q000737:chemistry; D017353:Gene Deletion; D005816:Genetic Complementation Test; D016680:Genome, Bacterial; D005838:Genotype; D006801:Humans; D007501:Iron / Q000737:chemistry*; D008024:Ligands; D008565:Membrane Proteins / Q000737:chemistry*; D009154:Mutation; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000737:chemistry*; D017262:Siderophores / Q000737:chemistry; D013997:Time Factors
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D002396:Catechols; D008024:Ligands; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D017262:Siderophores; C029489:enterobactin receptor; C057616:tonB protein, Bacteria; D004758:Enterobactin; D007501:Iron; C034221:catechol