Table of Contents
Journal of Signal Transduction
Volume 2012, Article ID 605905, 9 pages
http://dx.doi.org/10.1155/2012/605905
Review Article

ROS-Mediated Signalling in Bacteria: Zinc-Containing Cys-X-X-Cys Redox Centres and Iron-Based Oxidative Stress

1Department of Applied Genetics of Microorganisms, Faculty of Biology and Chemistry, University of Osnabrueck, Barbarastr. 13, 49069 Osnabrueck, Germany
2European Molecular Biology Laboratory (EMBL), EMBL Hamburg Outstation, c/o DESY, Building 25A, Notkestrasse 85, 22603 Hamburg, Germany

Received 12 May 2011; Revised 15 July 2011; Accepted 20 July 2011

Academic Editor: Lorenza Trabalzini

Copyright © 2012 Darío Ortiz de Orué Lucana et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Bacteria are permanently in contact with reactive oxygen species (ROS), both over the course of their life cycle as well that present in their environment. These species cause damage to proteins, lipids, and nucleotides, negatively impacting the organism. To detect these ROS molecules and to stimulate the expression of proteins involved in antioxidative stress response, bacteria use a number of different protein-based regulatory and sensory systems. ROS-based stress detection mechanisms induce posttranslational modifications, resulting in overall conformational and structural changes within sensory proteins. The subsequent structural rearrangements result in changes of protein activity, which lead to regulated and appropriate response on the transcriptional level. Many bacterial enzymes and regulatory proteins possess a conserved signature, the zinc-containing redox centre Cys-X-X-Cys in which a disulfide bridge is formed upon oxidative stress. Other metal-dependent oxidative modifications of amino acid side-chains (dityrosines, 2-oxo-histidines, or carbonylation) also modulate the activity of redox-sensitive proteins. Using molecular biology, biochemistry, biophysical, and structure biology tools, molecular mechanisms involved in sensing and response to oxidative stress have been elucidated in detail. In this review, we analyze some examples of bacterial redox-sensing proteins involved in antioxidative stress response and focus further on the currently known molecular mechanism of function.