Toggle Main Menu Toggle Search

Open Access padlockePrints

Iron-responsive regulation of the Helicobacter pylori iron-cofactored superoxide dismutase sodB is mediated by Fur

Lookup NU author(s): Dr Georg Homuth, Dr Ulrike Mader

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

Maintaining iron homeostasis is a necessity for all living organisms, as free iron augments the generation of reactive oxygen species like superoxide anions, at the risk of subsequent lethal cellular damage. The iron-responsive regulator Fur controls iron metabolism in many bacteria, including the important human pathogen Helicobacter pylori, and thus is directly or indirectly involved in regulation of oxidative stress defense. Here we demonstrate that Fur is a direct regulator of the H. pylori iron-cofactored superoxide dismutase SodB, which is essential for the defense against toxic superoxide radicals. Transcription of the sodB gene was iron induced in H. pylori wild-type strain 26695, resulting in expression of the SodB protein in iron-replete conditions but an absence of expression in iron-restricted conditions. Mutation of the fur gene resulted in constitutive, iron-independent expression of SodB. Recombinant H. pylori Fur protein bound with low affinity to the sodB promoter region, but addition of the iron substitute Mn2+ abolished binding. The operator sequence of the iron-free form of Fur, as identified by DNase I footprinting, was located directly upstream of the sodB gene at positions -5 to -47 from the transcription start site. The direct role of Fur in regulation of the H. pylori sodB gene contrasts with the small-RNA-mediated sodB regulation observed in Escherichia coli. In conclusion, H. pylori Fur is a versatile regulator involved in many pathways essential for gastric colonization, including superoxide stress defense. Copyright © 2005, American Society for Microbiology. All Rights Reserved.


Publication metadata

Author(s): Ernst FD, Homuth G, Stoof J, Mader U, Waidner B, Kuipers EJ, Kist M, Kusters JG, Bereswill S, Van Vliet AHM

Publication type: Article

Publication status: Published

Journal: Journal of Bacteriology

Year: 2005

Volume: 187

Issue: 11

Pages: 3687-3692

ISSN (print): 0021-9193

ISSN (electronic): 1098-5530

Publisher: American Society for Microbiology

URL: http://dx.doi.org/10.1128/JB.187.11.3687-3692.2005

DOI: 10.1128/JB.187.11.3687-3692.2005

PubMed id: 15901691


Altmetrics

Altmetrics provided by Altmetric


Actions

Find at Newcastle University icon    Link to this publication


Share