The ferroxidase centre of Escherichia coli bacterioferritin plays a key role in the reductive mobilisation of the mineral iron core

Bradley, Justin M., Bugg, Zinnia, Sackey, Aaren, Andrews, Simon C., Wilson, Michael T., Svistunenko, Dimitri A., Moore, Geoffrey R. and Le Brun, Nick E. ORCID: https://orcid.org/0000-0001-9780-4061 (2024) The ferroxidase centre of Escherichia coli bacterioferritin plays a key role in the reductive mobilisation of the mineral iron core. Angewandte Chemie-International Edition, 63 (16). ISSN 1433-7851

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Abstract

Ferritins are multimeric cage-forming proteins that play a crucial role in cellular iron homeostasis. All H-chain-type ferritins harbour a diiron site, the ferroxidase centre, at the centre of a 4 α–helical bundle, but bacterioferritins are unique in also binding 12 hemes per 24meric assembly. The ferroxidase centre is known to be required for the rapid oxidation of Fe2+ during deposition of an immobilised ferric mineral core within the protein’s hollow interior. In contrast, the heme of bacterioferritin is required for the efficient reduction of the mineral core during iron release, but has little effect on the rate of either oxidation or mineralisation of iron. Thus, the current view is that these two cofactors function in iron uptake and release, respectively, with no functional overlap. However, rapid electron transfer between the heme and ferroxidase centre of bacterioferritin from Escherichia coli was recently demonstrated, suggesting that the two cofactors may be functionally connected. Here we report absorbance and (magnetic) circular dichroism spectroscopies, together with in vitro assays of iron-release kinetics, which demonstrate that the ferroxidase centre plays an important role in the reductive mobilisation of the bacterioferritin mineral core, which is dependent on the heme-ferroxidase centre electron transfer pathway.

Item Type: Article
Uncontrolled Keywords: electron transfer,ferritin,heme,iron,iron homeostasis,magnetic circular dichroism,catalysis,chemistry(all) ,/dk/atira/pure/subjectarea/asjc/1500/1503
Faculty \ School: Faculty of Science > School of Chemistry (former - to 2024)
Faculty of Science
UEA Research Groups: Faculty of Science > Research Groups > Chemistry of Life Processes
Faculty of Science > Research Centres > Centre for Molecular and Structural Biochemistry
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Depositing User: LivePure Connector
Date Deposited: 04 Mar 2024 18:39
Last Modified: 25 Sep 2024 17:41
URI: https://ueaeprints.uea.ac.uk/id/eprint/94559
DOI: 10.1002/anie.202401379

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