title: New insights into the protective effect of manganese against oxidative stress.
abstract: Manganese has emerged as an important trace element in bacterial physiology. The correlation between manganese accumulation and resistance to oxidative stress has led to the suggestion that, in addition to a role as a prosthetic group in superoxide dismutase, manganese could exert its antioxidant effect via non-enzymatic redox reactions. The article by Anjem et al. in the current issue of Molecular Microbiology investigates the role of manganese ions in the defence against hydrogen peroxide in Escherichia coli. The results indicate that the redox activity of manganese is not linked to its protective effect. Instead, it is suggested that manganese replaces ferrous iron in enzymes that contain divalent cations at their active site. This enables the cell to avoid oxidative stress associated with iron release in the presence of hydrogen peroxide.
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane 4072, Australia. mcewan@uq.edu.au
authors.forename: Alastair G
authors.initials: AG
authors.lastname: McEwan
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D008345:Manganese / Q000378:metabolism*; D018384:Oxidative Stress; D012097:Repressor Proteins / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C499299:oxyR protein, E coli; D008345:Manganese; D006861:Hydrogen Peroxide; D007501:Iron; C095500:SodA protein, Bacteria; D013482:Superoxide Dismutase