Rubrerythrin-catalyzed substrate oxidation by dioxygen and hydrogen peroxide

Coulter, Eric D.; Shenvi, Neeta; Beharry, Zanna; Smith, Jennifer; Prickril, Benet C.; Kurtz, Donald M.

doi:10.1016/s0020-1693(99)00374-6

Cited by 38 publications

(72 citation statements)

References 40 publications

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“…This protection by Rbr and Ngr apparently occurs in competition with at least some of the 30 or more other proteins that are induced in response to peroxide stress in E. coli (34). As is the case for Rbo, the protection against hydrogen peroxide by Rbr and Ngr presumably requires an endogenous electron source, perhaps functioning analogously to the in vitro NADH peroxidase activity (reaction 4) (12,13 (46), the D. vulgaris catalase might complement the intracellular Rbr-catalyzed hydrogen peroxide removal by diminishing high concentrations of extracellular hydrogen peroxide, which is freely diffusible across cell membranes (Fig. 6).…”

Section: Discussionmentioning

confidence: 94%

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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Section: Discussionmentioning

confidence: 94%

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

et al. 2001

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“…§ Engineered substitutions of a serine for a cysteine ligand residue are known to result in stable ferric [Fe(SCys) 3 (OSer)] sites in rubredoxins and rubrerythrin with absorption features in the visible region that are blue-shifted from those of the [Fe(SCys) 4 ] sites (39,40). The absorption spectra of the C13S variant, however, show no evidence of such blue-shifted features.…”

Section: Resultsmentioning

confidence: 99%

An engineered two-iron superoxide reductase lacking the [Fe(SCys) ₄ ] site retains its catalytic properties in vitro and in vivo

Emerson

Cabelli

Kurtz

2003

Proc. Natl. Acad. Sci. U.S.A.

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Superoxide reductases (SORs) contain a characteristic square-pyramidal [Fe(NHis)4(SCys)] active site that catalyzes reduction of superoxide to hydrogen peroxide in several anaerobic bacteria and archaea. Some SORs, referred to as two-iron SORs (2Fe-SORs), also contain a lower-potential [Fe(SCys)4] site that is presumed to have an electron transfer function. However, the intra- and inter-subunit distances between [Fe(SCys)4] and [Fe(NHis)4(SCys)] iron centers within the 2Fe-SOR homodimer seem too long for efficient electron transfer between these sites. The possible role of the [Fe(SCys)4] site in 2Fe-SORs was addressed in this work by examination of an engineered Desulfovibrio vulgaris 2Fe-SOR variant, C13S, in which one ligand residue of the [Fe(SCys)4] site, cysteine 13, was changed to serine. This single amino acid residue change destroyed the native [Fe(SCys)4] site with complete loss of its iron, but left the [Fe(NHis)4(SCys)] site and the protein homodimer intact. The spectroscopic, redox and superoxide reactivity properties of the [Fe(NHis)4(SCys)] site in the C13S variant were nearly indistinguishable from those of the wild-type 2Fe-SOR. Aerobic growth complementation of a superoxide dismutase (SOD)-deficient Escherichia coli strain showed that the presence of the [Fe(NHis)4(SCys)] site in C13S 2Fe-SOR was apparently sufficient to catalyze reduction of the intracellular superoxide to nonlethal levels. As is the case for the wild-type protein, C13S 2Fe-SOR did not show any detectable SOD activity, i.e., destruction of the [Fe(SCys)4] site did not unmask latent SOD activity of the [Fe(NHis)4(SCys)] site. Possible alternative roles for the [Fe(SCys)4] site in 2Fe-SORs are considered

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“…Although D. vulgaris rubrerythrin (4, 7-9, 12, 27, 30, 35, 42) and the rubrerythrins from a variety of other microorganisms (2,3,10,16,28,47) have been extensively studied, its cellular function is still not understood. A number of enzyme activities have been reported for rubrerythrin, including pyrophosphatase (30), ferroxidase (4), and NADH peroxidase (7)(8)(9), but which are of physiological significance and the nature of its redox partner proteins have not been established. Even the true metal content of rubrerythrin is still a matter of controversy.…”

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Rubrerythrin from the Hyperthermophilic Archaeon Pyrococcus furiosus Is a Rubredoxin-Dependent, Iron-Containing Peroxidase

et al. 2004

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Rubrerythrin was purified by multistep chromatography under anaerobic, reducing conditions from the hyperthermophilic archaeon Pyrococcus furiosus. It is a homodimer with a molecular mass of 39.2 kDa and contains 2.9 ؎ 0.2 iron atoms per subunit. The purified protein had peroxidase activity at 85°C using hydrogen peroxide with reduced P. furiosus rubredoxin as the electron donor. The specific activity was 36 mol of rubredoxin oxidized/min/mg with apparent K m values of 35 and 70 M for hydrogen peroxide and rubredoxin, respectively. When rubrerythrin was combined with rubredoxin and P. furiosus NADH:rubredoxin oxidoreductase, the complete system used NADH as the electron donor to reduce hydrogen peroxide with a specific activity of 7.0 mol of H 2 O 2 reduced/min/mg of rubrerythrin at 85°C. Strangely, as-purified (reduced) rubrerythrin precipitated when oxidized by either hydrogen peroxide, air, or ferricyanide. The gene (PF1283) encoding rubrerythrin was expressed in Escherichia coli grown in medium with various metal contents. The purified recombinant proteins each contained approximately three metal atoms/subunit, ranging from 0.4 Fe plus 2.2 Zn to 1.9 Fe plus 1.2 Zn, where the metal content of the protein depended on the metal content of the E. coli growth medium. The peroxidase activities of the recombinant forms were proportional to the iron content. P. furiosus rubrerythrin is the first to be characterized from a hyperthermophile or from an archaeon, and the results are the first demonstration that this protein functions in an NADH-dependent, hydrogen peroxide: rubredoxin oxidoreductase system. Rubrerythrin is proposed to play a role in the recently defined anaerobic detoxification pathway for reactive oxygen species.

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Rubrerythrin-catalyzed substrate oxidation by dioxygen and hydrogen peroxide

Cited by 38 publications

References 40 publications

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

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

An engineered two-iron superoxide reductase lacking the [Fe(SCys) ₄ ] site retains its catalytic properties in vitro and in vivo

Rubrerythrin from the Hyperthermophilic Archaeon Pyrococcus furiosus Is a Rubredoxin-Dependent, Iron-Containing Peroxidase

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Rubrerythrin-catalyzed substrate oxidation by dioxygen and hydrogen peroxide

Cited by 38 publications

References 40 publications

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

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

An engineered two-iron superoxide reductase lacking the [Fe(SCys) 4 ] site retains its catalytic properties in vitro and in vivo

Rubrerythrin from the Hyperthermophilic Archaeon Pyrococcus furiosus Is a Rubredoxin-Dependent, Iron-Containing Peroxidase

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An engineered two-iron superoxide reductase lacking the [Fe(SCys) ₄ ] site retains its catalytic properties in vitro and in vivo