Kendall, JJ, Barrero-Tobon, AM, Hendrixson, DR et al. (1 more author) (2013) Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron-sulphur cluster enzymes from oxidative damage. Environmental Microbiology, 16 (4). pp. 1105-1121.
Abstract
Microaerophilic bacteria are adapted to low oxygen environments, but the mechanisms by which their growth in air is inhibited are not well understood. The citric-acid cycle in the microaerophilic pathogen Campylobacter jejuni is potentially vulnerable, as it employs pyruvate and 2-oxoglutarate: acceptor oxidoreductases (Por and Oor), which contain labile [4Fe-4S] centres. Here, we show that both enzymes are rapidly inactivated after exposure of cells to a fully aerobic environment. We investigated the mechanisms that might protect enzyme activity and identify a role for the hemerythrin HerA (Cj0241). A herA mutant exhibits an aerobic growth defect and reduced Por and Oor activities after exposure to 21% v/v oxygen. Slow anaerobic recovery of these activities after oxygen damage was observed, but at similar rates in both wild-type and herA strains, suggesting the role of HerA is to prevent Fe-S cluster damage, rather than promote repair. Another hemerythrin (HerB; Cj1224) also plays a protective role. Purified HerA and HerB exhibited optical absorption, ligand-binding and resonance Raman spectra typical of μ-oxo-bridged di-iron containing hemerythrins. We conclude that oxygen lability and poor repair of Por and Oor are major contributors to microaerophily in C. jejuni; hemerythrins help prevent enzyme damage microaerobically or during oxygen transients.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2013 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | 2-oxoglurate:acceptor oxidoreductase; Cj0241; Microaerophile; hydrogen peroxide; oxidative stress; pyruvate:acceptor oxidoreductase |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Molecular Biology and Biotechnology (Sheffield) |
Funding Information: | Funder Grant number BBSRC BB/D526810/1 BBSRC BB/F016832/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 22 Apr 2014 14:23 |
Last Modified: | 22 Apr 2014 14:23 |
Published Version: | http://dx.doi.org/10.1111/1462-2920.12341 |
Status: | Published |
Publisher: | Wiley |
Refereed: | Yes |
Identification Number: | 10.1111/1462-2920.12341 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:78614 |