title: Bacterial [Cu,Zn]-superoxide dismutase: phylogenetically distinct from the eukaryotic enzyme, and not so rare after all!
abstract: Copper- and zinc-containing superoxide dismutases ([Cu,Zn]-SODs) are generally considered almost exclusively eukaryotic enzymes, protecting the cytosol and extracellular compartments of higher organisms from damage by oxygen free-radicals. The recent description of a few examples of bacterial forms of the enzyme, located in the periplasm of different Gram-negative micro-organisms, prompted a re-evaluation of this general perception. A PCR-based approach has been developed and used successfully to identify bacterial genes encoding [Cu,Zn]-SOD in a wide range of important human and animal pathogens-members of the Haemophilus, Actinobacillus and Pasteurella (HAP) group, and Neisseria meningitidis. Comparison of [Cu,Zn]-SOD peptide sequences found in Haemophilus ducreyi, Actinobacillus pleuropneumoniae, Actinobacillus actinomycetemcomitans, Pasteurella multocida, and N. meningitidis with previously described bacterial proteins and examples of eukaryotic [Cu,Zn]-SOD has shown that the bacterial proteins constitute a distinct family apparently widely separated in evolutionary terms from the eukaryotic examples. The widespread occurrence of [Cu,Zn]-SOD in the periplasm of bacterial pathogens, appropriately located to dismute exogenously derived superoxide radical anions, suggests that this enzyme may play a role in the interactive biology of organisms with their hosts and so contribute to their capacity to cause disease.
mesh_terms: D000188:Actinobacillus / Q000201:enzymology / Q000235:genetics; D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003300:Copper; D005057:Eukaryotic Cells / Q000201:enzymology*; D019143:Evolution, Molecular; D005798:Genes, Bacterial; D006190:Haemophilus / Q000201:enzymology / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D010325:Pasteurella / Q000201:enzymology / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017385:Sequence Homology; D013045:Species Specificity; D013482:Superoxide Dismutase / Q000235:genetics*; D015032:Zinc
chemical_list: D001426:Bacterial Proteins; D003300:Copper; D013482:Superoxide Dismutase; D015032:Zinc