A copper(I) protein possibly involved in the assembly of Cu
 A
 center of bacterial cytochrome
 c
 oxidase

Banci, Lucia; Bertini, Ivano; Ciofi‐Baffoni, Simone; Katsari, Efthalia; Katsaros, Nikos; Kubíček, Karel; Mangani, Stefano

doi:10.1073/pnas.0406150102

Cited by 88 publications

(102 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The product of pcuC is predicted to be secreted to the periplasm by the Sec system and is homologous to the bacterial Cu(I) protein PCu A C (periplasmic Cu A chaperone), including the conserved Cu(I)-binding H(M)X 10 MX 21 HXM motif. In other bacterial species, PCu A C directs the insertion of Cu(I) into the Cu A site of cytochrome ba 3 oxidase (18). The product of senC2 is a member of the bacterial homologs of Sco1, involved in the assembly of the Cu A center of cytochrome oxidases in mitochondria.…”

Section: Resultsmentioning

confidence: 99%

Copper control of bacterial nitrous oxide emission and its impact on vitamin B ₁₂ -dependent metabolism

Sullivan

Gates

Appia-Ayme

et al. 2013

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

125

116

View full text Add to dashboard Cite

Global agricultural emissions of the greenhouse gas nitrous oxide (N 2 O) have increased by around 20% over the last 100 y, but regulation of these emissions and their impact on bacterial cellular metabolism are poorly understood. Denitrifying bacteria convert nitrate in soils to inert di-nitrogen gas (N 2 ) via N 2 O and the biochemistry of this process has been studied extensively in Paracoccus denitrificans. Here we demonstrate that expression of the gene encoding the nitrous oxide reductase (NosZ), which converts N 2 O to N 2 , is regulated in response to the extracellular copper concentration. We show that elevated levels of N 2 O released as a consequence of decreased cellular NosZ activity lead to the bacterium switching from vitamin B 12 -dependent to vitamin B 12 -independent biosynthetic pathways, through the transcriptional modulation of genes controlled by vitamin B 12 riboswitches. This inhibitory effect of N 2 O can be rescued by addition of exogenous vitamin B 12 .denitrification | transcription | NosR | NosC G lobal atmospheric loading of the ozone-depleting greenhouse gas, nitrous oxide (N 2 O), is on the increase (1). Molecule for molecule, its radiative potential is ∼300-fold higher than carbon dioxide (2, 3), comprising ∼9% of global radiative forcing by greenhouse gases (4). In addition, atmospheric N 2 O is stable for ∼120 y. Approximately 70% of anthropogenic N 2 O loading arises from agriculture, mainly from the use of nitrogencontaining fertilizers by soil microbes for dissimilatory purposes. Taken together, these features make N 2 O an important target for mitigation strategies (5).N 2 O is an intermediate in the sequential reduction of nitrate (NO 3 − ) to di-nitrogen (N 2 ), via nitrite (NO 2 − ), nitric oxide (NO), and N 2 O, a process known as denitrification (6). Under certain conditions, the final step in denitrification is dispensed with and N 2 O is released into the atmosphere. One limiting factor in this process is copper (Cu) availability, the metal cofactor required by the N 2 O reductase (NosZ) that destroys N 2 O (5, 7, 8). During Cu-limitation the catalytic capacity of the Nos system may be exceeded by the rate of the preceding reactions that generate N 2 O (i.e., NO 3 − , NO 2 − , and NO reduction) and thus, N 2 O is emitted by denitrifying bacteria (7, 9, 10).Much attention has been given to the cytotoxic properties of NO as a free-radical and oxidant, but N 2 O is often described as a relatively inert intermediate of the nitrogen cycle. However, N 2 O exhibits cytotoxicity, as it is known to bind to and inactivate vitamin B 12 (B 12 ), an essential cellular cofactor in B 12 -dependent enzymes involved in methionine and DNA synthesis (11,12). B 12 also acts as a ligand for B 12 riboswitches that modulate gene expression in the absence of this cofactor (13,14). The possible impact of environmental N 2 O emissions on B 12 metabolism in microbiological communities has largely been ignored. As levels of N 2 O increase in the environment, there is a compelling argument for ...

show abstract

Section: Resultsmentioning

confidence: 99%

Copper control of bacterial nitrous oxide emission and its impact on vitamin B ₁₂ -dependent metabolism

Sullivan

Gates

Appia-Ayme

et al. 2013

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

125

116

View full text Add to dashboard Cite

show abstract

“…Accordingly, the highly negative reduction potential values of the two metal-binding Cys residues in apoHSco1 and apoHSco2 (14,15) suggest that a reductant capable of reducing their disulfide bonds is needed for them to be able to bind the copper(I) ion. This feature is even more compelling in Grampositive and Gram-negative bacteria, where a similar pathway for copper transport and incorporation in CcO, involving Sco proteins (22,23), occurs outside of the cell or in the periplasmic space, respectively, where Cys residues in Sco and Cu A sites can presumably be oxidized by the aerobic environment.…”

mentioning

confidence: 99%

Mitochondrial copper(I) transfer from Cox17 to Sco1 is coupled to electron transfer

Banci

Bertini²,

Ciofi‐Baffoni³

et al. 2008

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

Self Cite

168

133

View full text Add to dashboard Cite

The human protein Cox17 contains three pairs of cysteines. In the mitochondrial intermembrane space (IMS) it exists in a partially oxidized form with two S-S bonds and two reduced cysteines (HCox172S-S). HCox172S-S is involved in copper transfer to the human cochaperones Sco1 and Cox11, which are implicated in the assembly of cytochrome c oxidase. We show here that Cu(I)HCox172S-S, i.e., the copper-loaded form of the protein, can transfer simultaneously copper(I) and two electrons to the human cochaperone Sco1 (HSco1) in the oxidized state, i.e., with its metal-binding cysteines forming a disulfide bond. The result is Cu(I)HSco1 and the fully oxidized apoHCox173S-S, which can be then reduced by glutathione to apoHCox172S-S. The HSco1/ HCox172S-S redox reaction is thermodynamically driven by copper transfer. These reactions may occur in vivo because HSco1 can be found in the partially oxidized state within the IMS, consistent with the variable redox properties of the latter compartment. The electron transfer-coupled metallation of HSco1 can be a mechanism within the IMS for an efficient specific transfer of the metal to proteins, where metal-binding thiols are oxidized. The same reaction of copper-electron-coupled transfer does not occur with the human homolog of Sco1, HSco2, for kinetic reasons that may be ascribed to the lack of a specific metal-bridged protein-protein complex, which is instead observed in the Cu(I)HCox172S-S/HSco1 interaction.cytochrome c oxidase assembly ͉ copper chaperone ͉ mitochondrial chemistry ͉ NMR

show abstract

“…Cu(I) is thought to be transferred from Cox17 to Sco1 for insertion of Cu into subunit II [Heaton et al, 2001;Nittis et al, 2001]. Recently a homologous protein for Cox17 has been found in bacteria [Banci et al, 2005]. The Sco1 homologue YmpQ of Bacillus subtilis affects cytochrome c oxidase but not menaquinol oxidase, an observation that supports a role in Cu A synthesis [Mattatall et al, 2000].…”

Section: Scop Candidate Protein For Cu a Assemblymentioning

confidence: 83%

Biogenesis of the Bacterial Respiratory CuA, Cu-S Enzyme Nitrous Oxide Reductase

Zumft¹

2005

Microb Physiol

View full text Add to dashboard Cite

Nitrous oxide reductase (NosZ, EC 1.7.99.6) is the terminal oxidoreductase of a respiratory electron transfer chain that transforms nitrous oxide to dinitrogen. The enzyme carries six Cu atoms. Two are arranged in the mixed-valent binuclear Cu_A site, and four make up the µ₄-sulfide-bridged Cu cluster, Cu_Z. The biogenesis of a catalytically active NosZ requires auxiliary functions for metal center assembly in the periplasm. Both Tat and Sec pathways share the task to transport the various Nos proteins to their functional sites. Biogenesis of NosZ requires an ABC transporter complex and the periplasmic Cu chaperone NosL. Sustaining whole-cell NosZ function depends on the periplasmic, FAD-containing protein NosX, and the membrane-bound iron-sulfur flavoprotein NosR. Most components with a biogenetic function are now amenable to structural studies.

show abstract

A copper(I) protein possibly involved in the assembly of Cu _A center of bacterial cytochrome c oxidase

Cited by 88 publications

References 49 publications

Copper control of bacterial nitrous oxide emission and its impact on vitamin B ₁₂ -dependent metabolism

Copper control of bacterial nitrous oxide emission and its impact on vitamin B ₁₂ -dependent metabolism

Mitochondrial copper(I) transfer from Cox17 to Sco1 is coupled to electron transfer

Biogenesis of the Bacterial Respiratory Cu<sub>A</sub>, Cu-S Enzyme Nitrous Oxide Reductase

Contact Info

Product

Resources

About

A copper(I) protein possibly involved in the assembly of Cu A center of bacterial cytochrome c oxidase

Cited by 88 publications

References 49 publications

Copper control of bacterial nitrous oxide emission and its impact on vitamin B 12 -dependent metabolism

Copper control of bacterial nitrous oxide emission and its impact on vitamin B 12 -dependent metabolism

Mitochondrial copper(I) transfer from Cox17 to Sco1 is coupled to electron transfer

Biogenesis of the Bacterial Respiratory Cu<sub>A</sub>, Cu-S Enzyme Nitrous Oxide Reductase

Contact Info

Product

Resources

About

A copper(I) protein possibly involved in the assembly of Cu _A center of bacterial cytochrome c oxidase

Copper control of bacterial nitrous oxide emission and its impact on vitamin B ₁₂ -dependent metabolism

Copper control of bacterial nitrous oxide emission and its impact on vitamin B ₁₂ -dependent metabolism