Direct Identification of a Bacterial Manganese(II) Oxidase, the Multicopper Oxidase MnxG, from Spores of Several Different Marine
            <i>Bacillus</i>
            Species

Dick, Gregory J.; Torpey, Justin W.; Beveridge, Terry J.; Tebo, Bradley M.

doi:10.1128/aem.01240-07

Cited by 145 publications

(131 citation statements)

References 55 publications

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“…Biogeochemical cycling of manganese has important implications for the cycling of carbon, nitrogen, and trace metals (11,40,42). The cycling of manganese is slow abiotically but is vastly increased in the presence of manganese-oxidizing and -reducing organisms (30,39,48).…”

Section: Resultsmentioning

confidence: 99%

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Mn(II) Oxidation Is Catalyzed by Heme Peroxidases in “ Aurantimonas manganoxydans ” Strain SI85-9A1 and Erythrobacter sp. Strain SD-21

Anderson

Johnson

Caputo

et al. 2009

Appl Environ Microbiol

123

128

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A new type of manganese-oxidizing enzyme has been identified in two alphaproteobacteria, "Aurantimonas manganoxydans" strain SI85-9A1 and Erythrobacter sp. strain SD-21. These proteins were identified by tandem mass spectrometry of manganese-oxidizing bands visualized by native polyacrylamide gel electrophoresis in-gel activity assays and fast protein liquid chromatography-purified proteins. Proteins of both alphaproteobacteria contain animal heme peroxidase and hemolysin-type calcium binding domains, with the 350-kDa active Mn-oxidizing protein of A. manganoxydans containing stainable heme. The addition of both Ca 2؉ ions and H 2 O 2 to the enriched protein from Aurantimonas increased manganese oxidation activity 5.9-fold, and the highest activity recorded was 700 M min ؊1 mg ؊1 . Mn(II) is oxidized to Mn(IV) via an Mn(III) intermediate, which is consistent with known manganese peroxidase activity in fungi. The Mn-oxidizing protein in Erythrobacter sp. strain SD-21 is 225 kDa and contains only one peroxidase domain with strong homology to the first 2,000 amino acids of the peroxidase protein from A. manganoxydans. The heme peroxidase has tentatively been named MopA (manganese-oxidizing peroxidase) and sheds new light on the molecular mechanism of Mn oxidation in prokaryotes.

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Section: Resultsmentioning

confidence: 99%

“…None of these MCOs share significant homology except for their copper binding motifs (35), and only in Bacillus sp. (11) have MCOs been directly linked to Mn oxidation.…”

mentioning

confidence: 99%

Mn(II) Oxidation Is Catalyzed by Heme Peroxidases in “ Aurantimonas manganoxydans ” Strain SI85-9A1 and Erythrobacter sp. Strain SD-21

Anderson

Johnson

Caputo

et al. 2009

Appl Environ Microbiol

123

128

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“…However, several genes showed a markedly higher transcript abundance in the plume environment, including an MGI archaea ammonium transporter (8.6 times increase) and SUP05 genes for the sox sulfur oxidation system (10-20 times increase) (Figure 2). Notably absent from the abundant protein-coding transcripts were genes encoding known Mn-oxidizing enzymes such as the multicopper oxidases MnxG, CumA and MofA (for example, Dick et al, 2008b) or the heme peroxidase MopA (for example, Dick et al, 2008a;Anderson et al, 2009). Although expression of novel multicopper oxidases was observed (mRNA transcript abundance ranks 186, 282, 818 and 856; data not shown in Figure 2), this diverse family of enzymes oxidizes a wide range of substrates (Tebo et al, 2004), thus further investigation is required to evaluate their potential link to Mn oxidation.…”

Section: Resultsmentioning

confidence: 99%

The metatranscriptome of a deep-sea hydrothermal plume is dominated by water column methanotrophs and lithotrophs

et al. 2012

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Microorganisms mediate geochemical processes in deep-sea hydrothermal vent plumes, which are a conduit for transfer of elements and energy from the subsurface to the oceans. Despite this important microbial influence on marine geochemistry, the ecology and activity of microbial communities in hydrothermal plumes is largely unexplored. Here, we use a coordinated metagenomic and metatranscriptomic approach to compare microbial communities in Guaymas Basin hydrothermal plumes to background waters above the plume and in the adjacent Carmen Basin. Despite marked increases in plume total RNA concentrations (3-4 times) and microbially mediated manganese oxidation rates (15-125 times), plume and background metatranscriptomes were dominated by the same groups of methanotrophs and chemolithoautotrophs. Abundant community members of Guaymas Basin seafloor environments (hydrothermal sediments and chimneys) were not prevalent in the plume metatranscriptome. De novo metagenomic assembly was used to reconstruct genomes of abundant populations, including Marine Group I archaea, Methylococcaceae, SAR324 Deltaproteobacteria and SUP05 Gammaproteobacteria. Mapping transcripts to these genomes revealed abundant expression of genes involved in the chemolithotrophic oxidation of ammonia (amo), methane (pmo) and sulfur (sox). Whereas amo and pmo gene transcripts were abundant in both plume and background, transcripts of sox genes for sulfur oxidation from SUP05 groups displayed a 10-20-fold increase in plumes. We conclude that the biogeochemistry of Guaymas Basin hydrothermal plumes is mediated by microorganisms that are derived from seawater rather than from seafloor hydrothermal environments such as chimneys or sediments, and that hydrothermal inputs serve as important electron donors for primary production in the deep Gulf of California.

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“…Multicopper oxidases are a structurally and functionally diverse family of enzymes that have the capacity to oxidize a wide range of organic and inorganic substrates [e.g., Fe(II), diphenolics] (13). Multicopper oxidases have also been linked to Mn(II) oxidation in some bacteria, particularly the spores of Gram-positive Bacillus spp., where oxidation occurs on the outermost layer of the proteinaceous spore coat (14). More recent findings, however, indicate that laccase enzymes in some Basidiomycete fungi are responsible for the indirect production of reactive oxygen species (ROS), including superoxide (O 2 − ) in the presence of Mn(II) and organic chelators (e.g., oxalate) (15).…”

mentioning

confidence: 99%

Mn(II) oxidation by an ascomycete fungus is linked to superoxide production during asexual reproduction

Hansel

Zeiner

Santelli

et al. 2012

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

200

161

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Manganese (Mn) oxides are among the most reactive minerals within the environment, where they control the bioavailability of carbon, nutrients, and numerous metals. Although the ability of microorganisms to oxidize Mn(II) to Mn(III/IV) oxides is scattered throughout the bacterial and fungal domains of life, the mechanism and physiological basis for Mn(II) oxidation remains an enigma. Here, we use a combination of compound-specific chemical assays, microspectroscopy, and electron microscopy to show that a common Ascomycete filamentous fungus, Stilbella aciculosa , oxidizes Mn(II) to Mn oxides by producing extracellular superoxide during cell differentiation. The reactive Mn oxide phase birnessite and the reactive oxygen species superoxide and hydrogen peroxide are colocalized at the base of asexual reproductive structures. Mn oxide formation is not observed in the presence of superoxide scavengers (e.g., Cu) and inhibitors of NADPH oxidases (e.g., diphenylene iodonium chloride), enzymes responsible for superoxide production and cell differentiation in fungi. Considering the recent identification of Mn(II) oxidation by NADH oxidase-based superoxide production by a common marine bacterium ( Roseobacter sp.), these results introduce a surprising homology between some prokaryotic and eukaryotic organisms in the mechanisms responsible for Mn(II) oxidation, where oxidation appears to be a side reaction of extracellular superoxide production. Given the versatility of superoxide as a redox reactant and the widespread ability of fungi to produce superoxide, this microbial extracellular superoxide production may play a central role in the cycling and bioavailability of metals (e.g., Hg, Fe, Mn) and carbon in natural systems.

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Direct Identification of a Bacterial Manganese(II) Oxidase, the Multicopper Oxidase MnxG, from Spores of Several Different Marine Bacillus Species

Cited by 145 publications

References 55 publications

Mn(II) Oxidation Is Catalyzed by Heme Peroxidases in “ Aurantimonas manganoxydans ” Strain SI85-9A1 and Erythrobacter sp. Strain SD-21

Mn(II) Oxidation Is Catalyzed by Heme Peroxidases in “ Aurantimonas manganoxydans ” Strain SI85-9A1 and Erythrobacter sp. Strain SD-21

The metatranscriptome of a deep-sea hydrothermal plume is dominated by water column methanotrophs and lithotrophs

Mn(II) oxidation by an ascomycete fungus is linked to superoxide production during asexual reproduction

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