Pseudoazurin mediates periplasmic electron flow in a mutant strain of Paracoccus denitrificans lacking cytochrome c550

Koutný, Marek; Kučera, Igor; Tesařı́k, Radek; Tuřánek, Jaroslav; Spanning, Rob J.M. van

doi:10.1016/s0014-5793(99)00345-2

Cited by 21 publications

(18 citation statements)

References 14 publications

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“…Thus, either cytochrome c 550 or pseudoazurin is required for one, or most probably the only, step of the electron transfer pathway from the cytochrome bc 1 complex to cytochrome cd 1 . This conclusion is in agreement with the recent report that addition of pseudoazurin stimulated the rate of electron transfer from succinate to nitrite in rightside-out vesicles, which must have retained externally bound cytochrome cd 1 -type nitrite reductase, from cytochrome c 550 -deficient P. denitrificans (23). A previous proposal (28) that one or more additional c-type cytochromes act as alternatives to cytochrome c 550 in electron transfer to nitrite reductase is not supported by the present work.…”

Section: Discussionsupporting

confidence: 93%

A Mutant of Paracoccus denitrificans with Disrupted Genes Coding for Cytochrome c ₅₅₀ and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome cd ₁ Nitrite Reductase

et al. 2003

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In Paracoccus denitrificans, electrons pass from the membrane-bound cytochrome bc 1 complex to the periplasmic nitrite reductase, cytochrome cd 1 . The periplasmic protein cytochrome c 550 has often been implicated in this electron transfer, but its absence, as a consequence of mutation, has previously been shown to result in almost no attenuation in the ability of the nitrite reductase to function in intact cells. Here, the hypothesis that cytochrome c 550 and pseudoazurin are alternative electron carriers from the cytochrome bc 1 complex to the nitrite reductase was tested by construction of mutants of P. denitrificans that are deficient in either pseudoazurin or both pseudoazurin and cytochrome c 550 . The latter organism, but not the former (which is almost indistinguishable in this respect from the wild type), grows poorly under anaerobic conditions with nitrate as an added electron acceptor and accumulates nitrite in the medium. Growth under aerobic conditions with either succinate or methanol as the carbon source is not significantly affected in mutants lacking either pseudoazurin or cytochrome c 550 or both these proteins. We concluded that pseudoazurin and cytochrome c 550 are the alternative electron mediator proteins between the cytochrome bc 1 complex and the cytochrome cd 1 -type nitrite reductase. We also concluded that expression of pseudoazurin is mainly controlled by the transcriptional activator FnrP.

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Section: Discussionsupporting

confidence: 93%

A Mutant of Paracoccus denitrificans with Disrupted Genes Coding for Cytochrome c ₅₅₀ and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome cd ₁ Nitrite Reductase

et al. 2003

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“…In the presence of copper, however, the mutation in the gene encoding cytochrome c 550 had hardly any effect on the denitrifying potential of that mutant strain, indicating that a copper-dependent electron carrier substituted for cytochrome c 550 (51). A likely candidate is pseudoazurin, which is a type I blue copper protein and able to mediate electron transfer between the cytochrome bc 1 complex and the nitrite, nitric oxide, and nitrous oxide reductases in vitro (21,25,26). Indeed, it has been shown that a mutant strain deficient in cytochrome c 550 and pseudoazurin failed to reduce nitrite (30;Stuart Ferguson,unpublished data).…”

Section: Discussionmentioning

confidence: 99%

Cytochromes c ₅₅₀ , c ₅₅₂ , and c ₁ in the Electron Transport Network of Paracoccus denitrificans : Redundant or Subtly Different in Function?

Otten

Oost²,

Reijnders³

et al. 2001

J Bacteriol

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Paracoccus denitrificans strains with mutations in the genes encoding the cytochrome c 550 , c 552 , or c 1 and in combinations of these genes were constructed, and their growth characteristics were determined. Each mutant was able to grow heterotrophically with succinate as the carbon and free-energy source, although their specific growth rates and maximum cell numbers fell variably behind those of the wild type. Maximum cell numbers and rates of growth were also reduced when these strains were grown with methylamine as the sole free-energy source, with the triple cytochrome c mutant failing to grow on this substrate. Under anaerobic conditions in the presence of nitrate, none of the mutant strains lacking the cytochrome bc 1 complex reduced nitrite, which is cytotoxic and accumulated in the medium. The cytochrome c 550 -deficient mutant did denitrify provided copper was present. The cytochrome c 552 mutation had no apparent effect on the denitrifying potential of the mutant cells. The studies show that the cytochromes c have multiple tasks in electron transfer. The cytochrome bc 1 complex is the electron acceptor of the Q-pool and of amicyanin. It is also the electron donor to cytochromes c 550 and c 552 and to the cbb 3 -type oxidase. Cytochrome c 552 is an electron acceptor both of the cytochrome bc 1 complex and of amicyanin, as well as a dedicated electron donor to the aa 3 -type oxidase. Cytochrome c 550 can accept electrons from the cytochrome bc 1 complex and from amicyanin, whereas it is also the electron donor to both cytochrome c oxidases and to at least the nitrite reductase during denitrification. Deletion of the c-type cytochromes also affected the concentrations of remaining cytochromes c, suggesting that the organism is plastic in that it adjusts its infrastructure in response to signals derived from changed electron transfer routes.

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“…The physiological electron donors of P. denitrificans N 2 OR have long been established to be cytochrome c-550 and pseudoazurin [20,21]. In the first case, the docking simulation gave several solutions in the top 200 of each ranking with a favorable orientation for electron transfer ( Fig.…”

Section: General Analysismentioning

confidence: 99%

“…A steady-state kinetic study demonstrated that the interaction between the two proteins is mainly hydrophobic in nature and that mitochondrial cytochrome c is not a competent electron donor to this enzyme [18]. On the other hand, N 2 OR isolated from Paracoccus pantotrophus, an organism closely related to P. denitrificans, can accept electrons from cytochrome c-550 and pseudoazurin [19][20][21], and also from the mitochondrial cytochrome c [22]. A structural model for the electron transfer complex between P. denitrificans N 2 OR and either P. panthotropus cytochrome c-550 or P. panthotropus pseudoazurin has been proposed on the basis of a theoretical docking study [23].…”

Section: Introductionmentioning

confidence: 99%

The electron transfer complex between nitrous oxide reductase and its electron donors

Dell’Acqua

Moura

et al. 2011

J Biol Inorg Chem

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Identifying redox partners and the interaction surfaces is crucial for fully understanding electron flow in a respiratory chain. In this study, we focused on the interaction of nitrous oxide reductase (N 2 OR), which catalyzes the final step in bacterial denitrification, with its physiological electron donor, either a c-type cytochrome or a type 1 copper protein. The comparison between the interaction of N 2 OR from three different microorganisms, Pseudomonas nautica, Paracoccus denitrificans, and Achromobacter cycloclastes, with their physiological electron donors was performed through the analysis of the primary sequence alignment, electrostatic surface, and molecular docking simulations, using the bimolecular complex generation with global evaluation and ranking algorithm. The docking results were analyzed taking into account the experimental data, since the interaction is suggested to have either a hydrophobic nature, in the case of P. nautica N 2 OR, or an electrostatic nature, in the case of P. denitrificans N 2 OR and A. cycloclastes N 2 OR. A set of well-conserved residues on the N 2 OR surface were identified as being part of the electron transfer pathway from the redox partner to N 2 OR (Ala495, Asp519, Val524, His566 and Leu568 numbered according to the P. nautica N 2 OR sequence). Moreover, we built a model for Wolinella succinogenes N 2 OR, an enzyme that has an additional c-type-heme-containing domain. The structures of the N 2 OR domain and the c-type-heme-containing domain were modeled and the full-length structure was obtained by molecular docking simulation of these two domains. The orientation of the c-type-heme-containing domain relative to the N 2 OR domain is similar to that found in the other electron transfer complexes.

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Pseudoazurin mediates periplasmic electron flow in a mutant strain of Paracoccus denitrificans lacking cytochrome c₅₅₀

Cited by 21 publications

References 14 publications

A Mutant of Paracoccus denitrificans with Disrupted Genes Coding for Cytochrome c ₅₅₀ and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome cd ₁ Nitrite Reductase

A Mutant of Paracoccus denitrificans with Disrupted Genes Coding for Cytochrome c ₅₅₀ and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome cd ₁ Nitrite Reductase

Cytochromes c ₅₅₀ , c ₅₅₂ , and c ₁ in the Electron Transport Network of Paracoccus denitrificans : Redundant or Subtly Different in Function?

The electron transfer complex between nitrous oxide reductase and its electron donors

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Pseudoazurin mediates periplasmic electron flow in a mutant strain of Paracoccus denitrificans lacking cytochrome c550

Cited by 21 publications

References 14 publications

A Mutant of Paracoccus denitrificans with Disrupted Genes Coding for Cytochrome c 550 and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome cd 1 Nitrite Reductase

A Mutant of Paracoccus denitrificans with Disrupted Genes Coding for Cytochrome c 550 and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome cd 1 Nitrite Reductase

Cytochromes c 550 , c 552 , and c 1 in the Electron Transport Network of Paracoccus denitrificans : Redundant or Subtly Different in Function?

The electron transfer complex between nitrous oxide reductase and its electron donors

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Pseudoazurin mediates periplasmic electron flow in a mutant strain of Paracoccus denitrificans lacking cytochrome c₅₅₀

A Mutant of Paracoccus denitrificans with Disrupted Genes Coding for Cytochrome c ₅₅₀ and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome cd ₁ Nitrite Reductase

A Mutant of Paracoccus denitrificans with Disrupted Genes Coding for Cytochrome c ₅₅₀ and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome cd ₁ Nitrite Reductase

Cytochromes c ₅₅₀ , c ₅₅₂ , and c ₁ in the Electron Transport Network of Paracoccus denitrificans : Redundant or Subtly Different in Function?