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Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage
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:accep...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BlackWell Publishing Ltd
2014
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4257069/ https://www.ncbi.nlm.nih.gov/pubmed/24245612 http://dx.doi.org/10.1111/1462-2920.12341 |
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author | Kendall, John J Barrero-Tobon, Angelica M Hendrixson, David R Kelly, David J |
author_facet | Kendall, John J Barrero-Tobon, Angelica M Hendrixson, David R Kelly, David J |
author_sort | Kendall, John J |
collection | PubMed |
description | 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. |
format | Online Article Text |
id | pubmed-4257069 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | BlackWell Publishing Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-42570692014-12-12 Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage Kendall, John J Barrero-Tobon, Angelica M Hendrixson, David R Kelly, David J Environ Microbiol Research Articles 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. BlackWell Publishing Ltd 2014-04 2013-12-17 /pmc/articles/PMC4257069/ /pubmed/24245612 http://dx.doi.org/10.1111/1462-2920.12341 Text en Copyright © 2014 John Wiley & Sons Ltd http://creativecommons.org/licenses/by/3.0/ This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Articles Kendall, John J Barrero-Tobon, Angelica M Hendrixson, David R Kelly, David J Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage |
title | Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage |
title_full | Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage |
title_fullStr | Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage |
title_full_unstemmed | Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage |
title_short | Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage |
title_sort | hemerythrins in the microaerophilic bacterium campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4257069/ https://www.ncbi.nlm.nih.gov/pubmed/24245612 http://dx.doi.org/10.1111/1462-2920.12341 |
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