Bacterial iron acquisition mediated by outer membrane translocation and cleavage of a host protein

Mosbahi, Khedidja and Wojnowska, Marta and Albalat, Amaya and Walker, Daniel (2018) Bacterial iron acquisition mediated by outer membrane translocation and cleavage of a host protein. Proceedings of the National Academy of Sciences, 115 (26). pp. 6840-6845. (https://doi.org/10.1073/pnas.1800672115)

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Abstract

Iron is an essential micronutrient for most bacteria and is obtained from iron-chelating siderophores or directly from iron-containing host proteins. For Gram-negative bacteria, classical iron transport systems consist of an outer membrane receptor, a periplasmic binding protein, and an inner membrane ABC transporter, which work in concert to deliver iron from the cell surface to the cytoplasm. We recently showed that Pectobacterium spp. are able to acquire iron from ferredoxin, a small and stable 2Fe-2S iron sulfur cluster containing protein and identified the ferredoxin receptor, FusA, a TonB-dependent receptor that binds ferredoxin on the cell surface. The genetic context of fusA suggests an atypical iron acquisition system, lacking a periplasmic binding protein, although the mechanism through which iron is extracted from the captured ferredoxin has remained unknown. Here we show that FusC, an M16 family protease, displays a highly targeted proteolytic activity against plant ferredoxin, and that growth enhancement of Pectobacterium due to iron acquisition from ferredoxin is FusC-dependent. The periplasmic location of FusC indicates a mechanism in which ferredoxin is imported into the periplasm via FusA before cleavage by FusC, as confirmed by the uptake and accumulation of ferredoxin in the periplasm in a strain lacking fusC. The existence of homologous uptake systems in a range of pathogenic bacteria suggests that protein uptake for nutrient acquisition may be widespread in bacteria and shows that, similar to their endosymbiotic descendants mitochondria and chloroplasts, bacteria produce dedicated protein import systems

  • Item type:Article
    ID code:86387
    Dates:
    Date
    Event
    26 June 2018
    Published
    11 June 2018
    Published Online
    15 May 2018
    Accepted
    12 January 2018
    Submitted
    Notes:Copyright © 2018 the Author(s). Published by PNAS. Khedidja Mosbahi, Marta Wojnowska, Amaya Albalat, and Daniel Walker, Bacterial iron acquisition mediated by outer membrane translocation and cleavage of a host protein, Proceedings of the National Academy of Sciences (PNAS), 115 (26) 6840-6845, https://doi.org/10.1073/pnas.1800672115
    Subjects:Medicine > Pharmacy and materia medica
    Science > Microbiology
    Department:Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences
    Depositing user: Pure Administrator
    Date deposited:03 Aug 2023 15:02
    Last modified:17 Apr 2024 00:54
    URI:https://strathprints.strath.ac.uk/id/eprint/86387
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