Electron transfer patterns of the di-heme protein cytochrome c4 from Pseudomonas stutzeri

Raffalt, Anders Christer; Schmidt, Line Rieck; Christensen, Hans Erik Mølager; Chi, Qijin; Ulstrup, Jens

doi:10.1016/j.jinorgbio.2009.01.004

Cited by 19 publications

(25 citation statements)

References 32 publications

(65 reference statements)

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“…The molecular weights of the electrophoretic bands of P. putida EPS (<35 kDa) were similar to the bands of membrane fractions of spheroplasts from Pseudomonas stutzeri 23. This band interval of 25.6–19.7 kDa may be related to the di-heme protein cytochrome c 4 22, a membrane-bound bacterial electron transfer cytochrome found in Pseudomonas aeruginosa 24, P. stutzeri 25 and Shewanella baltica 26 that is involved in the electron-transport systems associated with both aerobic and anaerobic respiration. It has also been reported that the A 551 /A 522 ratio of cytochromes c 4 from P. aeruginosa and P. stutzeri were 1.36 and 1.21, respectively27, which were similar to the ratio of 1 found in P. putida EPS.…”

Section: Resultsmentioning

confidence: 54%

Redox properties of extracellular polymeric substances (EPS) from electroactive bacteria

Sheng

Cheng

et al. 2016

Sci Rep

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Although the capacity for electroactive bacteria to convert environmental metallic minerals and organic pollutants is well known, the role of the redox properties of microbial extracellular polymeric substances (EPS) in this process is poorly understood. In this work, the redox properties of EPS from two widely present electroactive bacterial strains (Shewanella oneidensis and Pseudomonas putida) were explored. Electrochemical analysis demonstrates that the EPS extracted from the two strains exhibited redox properties. Spectroelectrochemical and protein electrophoresis analyses indicate that the extracted EPS from S. oneidensis and P. putida contained heme-binding proteins, which were identified as the possible redox components in the EPS. The results of heme-mediated behavior of EPS may provide an insight into the important roles of EPS in electroactive bacteria to maximize their redox capability for biogeochemical cycling, environmental bioremediation and wastewater treatment.

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Section: Resultsmentioning

confidence: 54%

Redox properties of extracellular polymeric substances (EPS) from electroactive bacteria

Sheng

Cheng

et al. 2016

Sci Rep

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“…The values are consistent with the negative and positive electrostatic charges of the two domains. 11 The direction of the electrostatic field within the protein gives rise to the distinct heme redox potentials and directs the flow of the electron from the lower- to higher-potential heme. The DHCC from the Heliobacterium cytochrome bc complex, as studied here, however, has only one redox midpotential, 42 indicating similar chemical environments around the two heme-binding pockets.…”

Section: Resultsmentioning

confidence: 99%

“…In general, an electron transfer of one metal center induces conformational changes in the site of the other, and that usually enhances the rates of subsequent steps. 11 Studying the structure, function, and redox properties of this protein is crucial to the understanding of the function of the entire heliobacterial cytochrome bc complex. Furthermore, an understanding of the Heliobacterium electron-transport chain (ETC), which is simpler and smaller than later evolved organisms, can provide clues about how life and photosynthesis evolved on Earth and possibly on other planets.…”

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confidence: 99%

Structural Analysis of Diheme Cytochrome c by Hydrogen–Deuterium Exchange Mass Spectrometry and Homology Modeling

et al. 2014

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A lack of X-ray or nuclear magnetic resonance structures of proteins inhibits their further study and characterization, motivating the development of new ways of analyzing structural information without crystal structures. The combination of hydrogen–deuterium exchange mass spectrometry (HDX-MS) data in conjunction with homology modeling can provide improved structure and mechanistic predictions. Here a unique diheme cytochrome c (DHCC) protein from Heliobacterium modesticaldum is studied with both HDX and homology modeling to bring some definition of the structure of the protein and its role. Specifically, HDX data were used to guide the homology modeling to yield a more functionally relevant structural model of DHCC.

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“…Cytochromes c 4 are periplasmic or membrane-bound members of class I cytochromes c with a molecular mass of ∼20 kDa found in a variety of bacteria [37], [38]. Analysis of the characterized cytochromes c 4 from Vibrio cholerae [39], Pseudoalteromonas haloplanktis [40], Pseudomonas aeruginosa , Azotobacter vinelandii [41], Acidithiobacillus ferrooxidans [42] and Pseudomonas stutzeri [43], [44], and the high resolution X-ray structures of the last two [45], [46] show that, similarly to T. thermophilus c 550 , these di-heme proteins are formed by two domains connected with a flexible, ∼10 aa long linker.…”

Section: Discussionmentioning

confidence: 99%

“…The positively charged C-terminal domain is proposed to interact with the negatively charged pocket of cytochrome c oxidase, while negatively charged N-terminal domain with a reductase [45]. However, despite the extensive characterization of P. stutzeri cytochrome c 4 (see references in [44]), its specific physiological function remains to be established as yet. Conversely, analysis of the cytochrome c 4 from A. ferrooxidans showed the crucial role of a negatively charged residue E121 localized on the overall positively charged C-terminal domain in recognition of its electron donor, rusticyanin, while the Y63 localized in the negatively charged N-terminal domain seems to be responsible for the electron transfer from c 4 to cytochrome c oxidase [51].…”

Section: Discussionmentioning

confidence: 99%

Functional Dissection of the Multi-Domain Di-Heme Cytochrome c550 from Thermus thermophilus

et al. 2013

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In bacteria, oxidation of sulfite to sulfate, the most common strategy for sulfite detoxification, is mainly accomplished by the molybdenum-containing sulfite:acceptor oxidoreductases (SORs). Bacterial SORs are very diverse proteins; they can exist as monomers or homodimers of their core subunit, as well as heterodimers with an additional cytochrome c subunit. We have previously described the homodimeric SOR from Thermus thermophilus HB8 (SORTTHB8), identified its physiological electron acceptor, cytochrome c 550, and demonstrated the key role of the latter in coupling sulfite oxidation to aerobic respiration. Herein, the role of this di-heme cytochrome c was further investigated. The cytochrome was shown to be composed of two conformationally independent domains, each containing one heme moiety. Each domain was separately cloned, expressed in E. coli and purified to homogeneity. Stopped-flow experiments showed that: i) the N-terminal domain is the only one accepting electrons from SORTTHB8; ii) the N- and C-terminal domains are in rapid redox equilibrium and iii) both domains are able to transfer electrons further to cytochrome c 552, the physiological substrate of the ba 3 and caa 3 terminal oxidases. These findings show that cytochrome c 550 functions as a electron shuttle, without working as an electron wire with one heme acting as the electron entry and the other as the electron exit site. Although contribution of the cytochrome c 550 C-terminal domain to T. thermophilus sulfur respiration seems to be dispensable, we suggest that di-heme composition of the cytochrome physiologically enables storage of the two electrons generated from sulfite oxidation, thereof ensuring efficient contribution of sulfite detoxification to the respiratory chain-mediated energy generation.

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Electron transfer patterns of the di-heme protein cytochrome c4 from Pseudomonas stutzeri

Cited by 19 publications

References 32 publications

Redox properties of extracellular polymeric substances (EPS) from electroactive bacteria

Redox properties of extracellular polymeric substances (EPS) from electroactive bacteria

Structural Analysis of Diheme Cytochrome c by Hydrogen–Deuterium Exchange Mass Spectrometry and Homology Modeling

Functional Dissection of the Multi-Domain Di-Heme Cytochrome c550 from Thermus thermophilus

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