Tellurite resistance gene trgB confers copper tolerance to Rhodobacter capsulatus

Rademacher, Corinna; Hoffmann, Marie-Christine; Lackmann, Jan-Wilm; Moser, Roman; Pfänder, Yvonne; Leimkühler, Silke; Narberhaus, Franz; Masepohl, Bernd

doi:10.1007/s10534-012-9566-2

Cited by 5 publications

(3 citation statements)

References 72 publications

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“…To determine whether the synergistic effect of Cu(II) and Fe(II) was unique to R. palustris, we tested the effects of Cu(II) and Fe(II) on E. coli MG1655, Shewanella oneidensis MR-1, and Rhodobacter capsulatus SB1003. The physiology of these organisms has been studied extensively, and their copper resistance systems have been at least partially characterized (12,(32)(33)(34). In testing the sensitivities of these organisms to copper and iron, we chose various copper and iron concentrations to reflect the various sensitivities to copper of the different bacterial taxa.…”

Section: Synergistic Effect Of Cu(ii) and Fe(ii)mentioning

confidence: 99%

Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria

Bird

Coleman

Newman

2013

Appl Environ Microbiol

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bTransition metals are known to cause toxic effects through their interaction with oxygen, but toxicity under anoxic conditions is poorly understood. Here we investigated the effects of iron (Fe) and copper (Cu) on the anaerobic growth and gene expression of the purple phototrophic bacterium Rhodopseudomonas palustris TIE-1. We found that Fe(II) and Cu(II) act synergistically to delay anaerobic growth at environmentally relevant metal concentrations. Cu(I) and Cu(II) had similar effects both alone and in the presence of ascorbate, a Cu(II) reductant, indicating that reduction of Cu(II) to Cu(I) by Fe(II) is not sufficient to explain the growth inhibition. Addition of Cu(II) increased the toxicity of Co(II) and Ni(II); in contrast, Ni(II) toxicity was diminished in the presence of Fe(II). The synergistic anaerobic toxicity of Fe(II) and Cu(II) was also observed for Escherichia coli MG1655, Shewanella oneidensis MR-1, and Rhodobacter capsulatus SB1003. Gene expression analyses for R. palustris identified three regulatory genes that respond to Cu(II) and not to Fe(II): homologs of cueR and cusR, two known proteobacterial copper homeostasis regulators, and csoR, a copper regulator recently identified in Mycobacterium tuberculosis. Two P-type ATPase efflux pumps, along with an F o F 1 ATP synthase, were also upregulated by Cu(II) but not by Fe(II). An Escherichia coli mutant deficient in copA, cus, and cueO showed a smaller synergistic effect, indicating that iron might interfere with one or more of the copper homeostasis systems. Our results suggest that interactive effects of transition metals on microbial physiology may be widespread under anoxic conditions, although the molecular mechanisms remain to be more fully elucidated.

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Section: Synergistic Effect Of Cu(ii) and Fe(ii)mentioning

confidence: 99%

Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria

Bird

Coleman

Newman

2013

Appl Environ Microbiol

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“…The α‐proteobacterium Rhodobacter capsulatus has developed into an attractive model organism for studying Cu homeostasis. In this species, multiple proteins were identified that target Cu to cuproproteins like the cbb 3 ‐type cytochrome c oxidase ( cbb 3 ‐Cox), export excess Cu into the periplasm (Ekici et al , ), or mediate Cu resistance (Rademacher et al , ; Rademacher and Masepohl, ). The cbb 3 ‐Cox contains a single Cu atom (Cu B ) within the catalytic center of subunit CcoN, where oxygen is reduced to water (Gray et al , ).…”

Section: Introductionmentioning

confidence: 99%

The Cu chaperone CopZ is required for Cu homeostasis in Rhodobacter capsulatus and influences cytochrome cbb₃ oxidase assembly

Utz

Andrei

Milanov

et al. 2019

Molecular Microbiology

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Summary Cu homeostasis depends on a tightly regulated network of proteins that transport or sequester Cu, preventing the accumulation of this toxic metal while sustaining Cu supply for cuproproteins. In Rhodobacter capsulatus, Cu‐detoxification and Cu delivery for cytochrome c oxidase (cbb3‐Cox) assembly depend on two distinct Cu‐exporting P1B‐type ATPases. The low‐affinity CopA is suggested to export excess Cu and the high‐affinity CcoI feeds Cu into a periplasmic Cu relay system required for cbb3‐Cox biogenesis. In most organisms, CopA‐like ATPases receive Cu for export from small Cu chaperones like CopZ. However, whether these chaperones are also involved in Cu export via CcoI‐like ATPases is unknown. Here we identified a CopZ‐like chaperone in R. capsulatus, determined its cellular concentration and its Cu binding activity. Our data demonstrate that CopZ has a strong propensity to form redox‐sensitive dimers via two conserved cysteine residues. A ΔcopZ strain, like a ΔcopA strain, is Cu‐sensitive and accumulates intracellular Cu. In the absence of CopZ, cbb3‐Cox activity is reduced, suggesting that CopZ not only supplies Cu to P1B‐type ATPases for detoxification but also for cuproprotein assembly via CcoI. This finding was further supported by the identification of a ~150 kDa CcoI‐CopZ protein complex in native R. capsulatus membranes.

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“…21 On the other hand, more recently it was observed that the tellurite resistant determinant trgB, from the trgAB operon, confers copper resistance in Rhodobacter capsulatus by a still undetermined mechanism. 22 In the last century and mainly because of the industrial revolution, it became evident the dramatic increase of heavy metal/metalloid-polluted sites across the Earth surface, including pristine places such as Antarctica. 23,24 The Antarctic continent is constantly exposed to diverse abiotic stresses such as low temperatures, high salinity, and UV radiation, among others, which can cause oxidative stress in living organisms.…”

Section: Introductionmentioning

confidence: 99%

Mercury-mediated cross-resistance to tellurite in Pseudomonas spp. isolated from the Chilean Antarctic territory

et al. 2016

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Mercury salts and tellurite are among the most toxic compounds for microorganisms on Earth. Bacterial mercury resistance is established mainly via mercury reduction by the mer operon system. However, specific mechanisms underlying tellurite resistance are unknown to date. To identify new mechanisms for tellurite detoxification we demonstrate that mercury resistance mechanisms can trigger cross-protection against tellurite to a group of Pseudomonads isolated from the Chilean Antarctic territory. Sequencing of 16S rRNA of four isolated strains resulted in the identification of three Pseudomonads (ATH-5, ATH-41 and ATH-43) and a Psychrobacter (ATH-62) bacteria species. Phylogenetic analysis showed that ATH strains were related to other species previously isolated from cold aquatic and soil environments. Furthermore, the identified merA genes were related to merA sequences belonging to transposons commonly found in isolated bacteria from mercury contaminated sites. Pseudomonas ATH isolates exhibited increased tellurite resistance only in the presence of mercury, especially ATH-43. Determination of the growth curves, minimal inhibitory concentrations and growth inhibition zones showed different tellurite cross-resistance of the ATH strains and suggested a correlation with the presence of a mer operon. On the other hand, reactive oxygen species levels decreased while the thiol content increased when the isolates were grown in the presence of both toxicants. Finally, qPCR determinations of merA, merC and rpoS transcripts from ATH-43 showed a synergic expression pattern upon combined tellurite and mercury treatments. Altogether, the results suggest that mercury could trigger a cell response that confers mercury and tellurite resistance, and that the underlying mechanism participates in protection against oxidative damage.

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Tellurite resistance gene trgB confers copper tolerance to Rhodobacter capsulatus

Cited by 5 publications

References 72 publications

Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria

Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria

The Cu chaperone CopZ is required for Cu homeostasis in Rhodobacter capsulatus and influences cytochrome cbb₃ oxidase assembly

Mercury-mediated cross-resistance to tellurite in Pseudomonas spp. isolated from the Chilean Antarctic territory

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Tellurite resistance gene trgB confers copper tolerance to Rhodobacter capsulatus

Cited by 5 publications

References 72 publications

Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria

Iron and Copper Act Synergistically To Delay Anaerobic Growth of Bacteria

The Cu chaperone CopZ is required for Cu homeostasis in Rhodobacter capsulatus and influences cytochrome cbb3 oxidase assembly

Mercury-mediated cross-resistance to tellurite in Pseudomonas spp. isolated from the Chilean Antarctic territory

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The Cu chaperone CopZ is required for Cu homeostasis in Rhodobacter capsulatus and influences cytochrome cbb₃ oxidase assembly