Nucleotide sequence of a putative periplasmic Mn superoxide dismutase from Acinetobacter calcoaceticus ADP1

Geißdörfer, Walter; Ratajczak, Andreas; Hillen, Wolfgang

doi:10.1016/s0378-1119(96)00728-7

Cited by 12 publications

(11 citation statements)

References 13 publications

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“…Mn-SODs tend to be exported via Sec as unfolded proteins and hence acquire their metal outside the cell, where competition with iron may not be an issue (Fig. 1, B and C) (22)(23)(24)(25)(26). Such a model for metal ion selectivity by cell compartmentalization has previously been described by Robinson and colleagues (28) for other periplasmic metalloproteins.…”

Section: Mishaps In Metal Insertion Into Mn-sodmentioning

confidence: 57%

“…Although bacterial Mn/Fe-SODs are generally cytosolic, there are rare exceptions in which the enzyme is secreted into the periplasmic or extracellular space (22)(23)(24)(25)(26). Bacteria can export unfolded proteins through the Sec system or will use the twin-arginine translocation (TAT) system for exporting prefolded mature polypeptides (27).…”

Section: Mishaps In Metal Insertion Into Mn-sodmentioning

confidence: 99%

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Battles with Iron: Manganese in Oxidative Stress Protection

Aguirre

Culotta

2012

Journal of Biological Chemistry

262

204

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The redox-active metal manganese plays a key role in cellular adaptation to oxidative stress. As a cofactor for manganese superoxide dismutase or through formation of non-proteinaceous manganese antioxidants, this metal can combat oxidative damage without deleterious side effects of Fenton chemistry. In either case, the antioxidant properties of manganese are vulnerable to iron. Cellular pools of iron can outcompete manganese for binding to manganese superoxide dismutase, and through Fenton chemistry, iron may counteract the benefits of non-proteinaceous manganese antioxidants. In this minireview, we highlight ways in which cells maximize the efficacy of manganese as an antioxidant in the midst of pro-oxidant iron.In biology, iron and manganese play important roles in oxygen chemistry. Both metals are used in oxygen evolution through photosynthesis and can also serve as cofactors for enzymes that remove harmful byproducts of O 2 metabolism such as superoxide (O 2 . ) and hydrogen peroxide, yet a major difference lies in the propensity of these metals to cause oxidative damage. Iron is well known for its reactivity with peroxide, generating the highly reactive hydroxyl radical through so-called Fenton chemistry. Manganese is less prone to such chemistry due to a higher reduction potential. Iron is often considered a pro-oxidant in biology under situations in which manganese is an antioxidant. Without the deleterious side effects of Fenton chemistry, manganese can safely operate as a cofactor for superoxide dismutase (SOD) 2 enzymes and also provide oxidative stress resistance through formation of nonproteinaceous manganese-based antioxidants. Herein, we focus on these two biological roles of manganese in oxidative stress protection and the potential challenges faced by competing pools of iron. Manganese Versus Iron as Cofactors for SODSOD enzymes fall into three distinct families that are unrelated in sequence but have converged in evolution to utilize a redox-active metal to disproportionate O 2 . into hydrogen peroxide and oxygen. These families are classified according to metal cofactor and include Cu,Zn-SODs, which use copper for catalysis and also bind a structural zinc atom; a rarer family of nickel-containing SODs (1); and an extensive Mn/Fe-SOD family that uses either manganese or iron. Members of the Mn/Fe-SOD family are widespread in biology and are thought to have evolved from a common ancestor prior to the divergence of eubacteria, archaebacteria, and eukaryotes over 3 billion years ago (2, 3). The active sites of Mnand Fe-SODs are virtually indistinguishable. The manganese or iron cofactor is coordinated to three histidines, one aspartate, and one solvent molecule in a distorted trigonal bipyramidal geometry. Outside the active site, the overall primary sequence and tertiary folds of Mn-and Fe-SODs are remarkably similar. Despite this striking conservation, these SODs are exquisitely metal-specific; for example, a Mn-SOD is active only with manganese and not iron. Rare exceptions include so-called ...

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Section: Mishaps In Metal Insertion Into Mn-sodmentioning

confidence: 57%

Section: Mishaps In Metal Insertion Into Mn-sodmentioning

confidence: 99%

Battles with Iron: Manganese in Oxidative Stress Protection

Aguirre

Culotta

2012

Journal of Biological Chemistry

262

204

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“…Nevertheless, although 9 out of the 12 first residues were conserved (MSHTLPLALYAY for A. hydrophila vs MSYTLPSLPYAY for E. coli), the A. hydrophila MnSOD contained a potential signal sequence lacking in E. coli Fe-and MnSODs (Nielsen et al, 1997). A similar potential sequence suggesting a periplasmic location of the enzyme has been described in Acinetobacter calcoaceticus MnSOD (23 amino-terminal residues) (Geißdo$ rfer et al, 1997). In the fish pathogen Aeromonas salmonicida a periplasmic MnSOD has also been detected (Barnes et al, 1996) and a role in the pathogenicity was proposed by the authors.…”

Section: Discussionmentioning

confidence: 72%

Occurrence of two superoxide dismutases in Aeromonas hydrophila: molecular cloning and differential expression of the sodA and sodB genes

et al. 2001

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“…We have found no data addressing the localizations of SODs in other sulfate-reducing bacteria. A few other periplasmic Fe/Mn-SODs have been reported, but only from aerobes (4,16,37).…”

Section: Discussionmentioning

confidence: 99%

Rubrerythrin and Rubredoxin Oxidoreductase inDesulfovibrio vulgaris: a Novel Oxidative Stress Protection System

et al. 2001

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Evidence is presented for an alternative to the superoxide dismutase (SOD)-catalase oxidative stress defense system in Desulfovibrio vulgaris (strain Hildenborough). This alternative system consists of the nonheme iron proteins, rubrerythrin (Rbr) and rubredoxin oxidoreductase (Rbo), the product of the rbo gene (also called desulfoferrodoxin). A ⌬rbo strain of D. vulgaris was found to be more sensitive to internal superoxide exposure than was the wild type. Unlike Rbo, expression of plasmid-borne Rbr failed to restore the aerobic growth of a SOD-deficient strain of Escherichia coli. Conversely, plasmid-borne expression of two different Rbrs from D. vulgaris increased the viability of a catalase-deficient strain of E. coli that had been exposed to hydrogen peroxide whereas Rbo actually decreased the viability. A previously undescribed D. vulgaris gene was found to encode a protein having 50% sequence identity to that of E. coli Fe-SOD. This gene also encoded an extended N-terminal sequence with high homologies to export signal peptides of periplasmic redox proteins. The SOD activity of D. vulgaris is not affected by the absence of Rbo and is concentrated in the periplasmic fraction of cell extracts. These results are consistent with a superoxide reductase rather than SOD activity of Rbo and with a peroxidase activity of Rbr. A joint role for Rbo and Rbr as a novel cytoplasmic oxidative stress protection system in D. vulgaris and other anaerobic microorganisms is proposed.

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Nucleotide sequence of a putative periplasmic Mn superoxide dismutase from Acinetobacter calcoaceticus ADP1

Cited by 12 publications

References 13 publications

Battles with Iron: Manganese in Oxidative Stress Protection

Battles with Iron: Manganese in Oxidative Stress Protection

Occurrence of two superoxide dismutases in Aeromonas hydrophila: molecular cloning and differential expression of the sodA and sodB genes

Rubrerythrin and Rubredoxin Oxidoreductase inDesulfovibrio vulgaris: a Novel Oxidative Stress Protection System

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