title: Iron and proteins for iron storage and detoxification.
abstract: Iron is required by most organisms, but is potentially toxic due to the low solubility of the stable oxidation state, Fe(III), and to the tendency to potentiate the production of reactive oxygen species, ROS. The reactivity of iron is counteracted by bacteria with the same strategies employed by the host, namely by sequestering the metal into ferritin, the ubiquitous iron storage protein. Ferritins are highly conserved, hollow spheres constructed from 24 subunits that are endowed with ferroxidase activity and can harbour up to 4500 iron atoms as oxy-hydroxide micelles. The release of the metal upon reduction can alter the microorganism-host iron balance and hence permit bacteria to overcome iron limitation. In bacteria, the relevance of the Dps (DNA-binding proteins from starved cells) family in iron storage-detoxification has been recognized recently. The seminal studies on the protein from Listeria innocua demonstrated that Dps proteins have ferritin-like activity and most importantly have the capacity to attenuate the production of ROS. This latter function allows bacterial pathogens that lack catalase, e.g. Porphyromonas gingivalis, to survive in an aerobic environment and resist to peroxide stress.
authors.affiliation: CNR Institute of Molecular Biology and Pathology, Department of Biochemical Sciences, University of Rome La Sapienza, Rome, Italy.
authors.forename: Emilia
authors.initials: E
authors.lastname: Chiancone
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Ceci
authors.forename: Andrea
authors.initials: A
authors.lastname: Ilari
authors.forename: Frederica
authors.initials: F
authors.lastname: Ribacchi
authors.forename: Simonetta
authors.initials: S
authors.lastname: Stefanini
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D005293:Ferritins / Q000737:chemistry / Q000378:metabolism*; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010084:Oxidation-Reduction; D011487:Protein Conformation; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D017382:Reactive Oxygen Species; D005293:Ferritins; D007501:Iron