Molecular Evolution and Structure–Function Relationships of the Superoxide Dismutase Gene Families in Angiosperms and Their Relationship to Other Eukaryotic and Prokaryotic Superoxide Dismutases

Fink, Ryan C.; Scandalios, John G.

doi:10.1006/abbi.2001.2739

Cited by 195 publications

(140 citation statements)

References 53 publications

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“…Additionally, accumulation of weak acids in the culture medium has been shown to induce the catalase genes in E. coli (50) and to induce both catalase and superoxide dismutase in Listeria monocytogenes (20). Alignment of amino acid sequences of MnSODs from different prokaryotes and eukaryotes shows a high degree of homology, a highly conserved active center (22), and a conserved catalytic function(s) (i.e., to disproportionate O 2 ⅐ Ϫ to H 2 O 2 and O 2 ) (41). The role of MnSOD in protecting cells against oxidative stress is widely understood and accepted (25).…”

Section: Discussionmentioning

confidence: 99%

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Role of Antioxidant Enzymes in Bacterial Resistance to Organic Acids

Bruno-Bárcena

Azcarate‐Peril

Hassan³

2010

Appl Environ Microbiol

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Growth in aerobic environments has been shown to generate reactive oxygen species (ROS) and to cause oxidative stress in most organisms. Antioxidant enzymes (i.e., superoxide dismutases and hydroperoxidases) and DNA repair mechanisms provide protection against ROS. Acid stress has been shown to be associated with the induction of Mn superoxide dismutase (MnSOD) in Lactococcus lactis and Staphylococcus aureus. However, the relationship between acid stress and oxidative stress is not well understood. In the present study, we showed that mutations in the gene coding for MnSOD (sodA) increased the toxicity of lactic acid at pH 3.5 in Streptococcus thermophilus. The inclusion of the iron chelators 2,2-dipyridyl (DIP), diethienetriamine-pentaacetic acid (DTPA), and O-phenanthroline (O-Phe) provided partial protection against 330 mM lactic acid at pH 3.5. The results suggested that acid stress triggers an iron-mediated oxidative stress that can be ameliorated by MnSOD and iron chelators. These findings were further validated in Escherichia coli strains lacking both MnSOD and iron SOD (FeSOD) but expressing a heterologous MnSOD from S. thermophilus. We also found that, in E. coli, FeSOD did not provide the same protection afforded by MnSOD and that hydroperoxidases are equally important in protecting the cells against acid stress. These findings may explain the ability of some microorganisms to survive better in acidified environments, as in acid foods, during fermentation and accumulation of lactic acid or during passage through the low pH of the stomach.

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Section: Discussionmentioning

confidence: 99%

“…The Mn-and Fe-SODs of E. coli are highly homologous, and the levels of coordination of the metals in the active sites are nearly identical (22). Both enzymes are equally important in protecting E. coli against oxygen toxicity (25,30,49).…”

Section: Can Mnsod Protect S Thermophilus Against Acid Stress?mentioning

confidence: 99%

Role of Antioxidant Enzymes in Bacterial Resistance to Organic Acids

Bruno-Bárcena

Azcarate‐Peril

Hassan³

2010

Appl Environ Microbiol

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“…In cyanobacteria, MnSOD is found in the periplasm and is associated with the thylakoid membranes (Herbert et al, 1992;Chen et al, 2001;Li et al, 2002). In contrast, MnSOD is found in the mitochondria of embryophytes, chlorophytes, and dinoflagellates (Kliebenstein et al, 1998;Kitayama et al, 1999;Wu et al, 1999;Okamoto et al, 2001;Okomoto et al, 2001;Fink and Scandalios, 2002). Although some information has been shown regarding SOD in diatoms Ken et al, 2005), no information on the subcellular localization of MnSOD and the associated kinetics in diatoms is available.…”

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confidence: 99%

Localization and Role of Manganese Superoxide Dismutase in a Marine Diatom

et al. 2006

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Superoxide dismutase (SOD) catalyzes the transformation of superoxide to molecular oxygen and hydrogen peroxide. Of the four known SOD isoforms, distinguished by their metal cofactor (iron, manganese [Mn], copper/zinc, nickel), MnSOD is the dominant form in the diatom Thalassiosira pseudonana. We cloned the MnSOD gene, sodA, using the expression vector pBAD, overexpressed the product in Escherichia coli, and purified the mature protein (TpMnSOD). This recombinant enzyme was used to generate a polyclonal antibody in rabbit that recognizes MnSOD in T. pseudonana. Based on quantitative immunoblots, we calculate that in vivo concentrations of TpMnSOD are approximately 0.9 amol cell 21 using the recombinant protein as a standard. Immunogold staining indicates that TpMnSOD is localized in the chloroplasts, which is in contrast to most other eukaryotic algae (including chlorophytes and embryophytes) where MnSOD is localized exclusively in mitochondria. Based on the photosynthetic Mn complex in photosystem II, cellular Mn budgets cannot account for 50% to 80% of measured Mn within diatom cells. Our results reveal that chloroplastic MnSOD accounts for 10% to 20% of cellular Mn, depending on incident light intensity and cellular growth rate. Indeed, our analysis indicates that TpMnSOD accounts for 1.4% (60.2%) of the total protein in the cell. The TpMnSOD has a rapid turnover rate with an apparent half-life of 6 to 8 h when grown under continuous light. TpMnSOD concentrations increase relative to chlorophyll, with an increase in incident light intensity to minimize photosynthetic oxidative stress. The employment of a Mn-based SOD, linked to photosynthetic stress in T. pseudonana, may contribute to the continued success of diatoms in the low iron regions of the modern ocean.

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“…CgSod1 and ScSod1 are 91 % similar (84 % identical plus 7 % similar) and CgSod2 and ScSod2 are 81 % similar (70 % identical plus 11 % similar). In CgSod1 and CgSod2 the amino acid residues involved in metal ion coordination are conserved (Fink & Scandalios, 2002), and the first 24 amino acids of CgSod2 contain a putative targeting signal for mitochondria (Fig. S1).…”

Section: Sod1 Is a Cytoplasmic And Sod2 Is A Mitochondrial Proteinmentioning

confidence: 99%