Iron transport in Francisella in the absence of a recognizable TonB protein still requires energy generated by the proton motive force

Lidia M. Crosa, Jorge H. Crosa, Fred Heffron

    Research output: Contribution to journalArticle

    8 Scopus citations


    The mechanism of iron transport in Francisella is still a puzzle since none of the sequenced Francisella strains appears to encode a TonB protein, the energy transducer of the proton motive force necessary to act on the bacterial outer membrane siderophore receptor to allow the internalization of iron. In this work we demonstrate using kinetic experiments of radioactive Fe 3+ utilization, that iron uptake in Francisella novicida, although with no recognizable TonB protein, is indeed dependent on energy generated by the proton motive force. Moreover, mutants of a predicted outer membrane receptor still transport iron and are sensitive to the iron dependent antimicrobial compound streptonigrin. Our studies suggest that alternative pathways to internalize iron might exist in Francisella.

    Original languageEnglish (US)
    Pages (from-to)337-344
    Number of pages8
    Issue number2
    StatePublished - Apr 1 2009



    • Francisella
    • Iron transport
    • Proton motive force

    ASJC Scopus subject areas

    • Biomaterials
    • Biochemistry, Genetics and Molecular Biology(all)
    • Agricultural and Biological Sciences(all)
    • Metals and Alloys

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