A. G. McEwan

Trade-off between iron uptake and protection against oxidative stress: Deletion of cueO promotes uropathogenic Escherichia coli virulence in a mouse model of urinary tract infection (2008)

Tree, J.J., Ulett, G.C., Trott, D.J., McEwan, A.G., Schembri, M.A.

A mechanistic and electrochemical study of the interaction between dimethyl sulfide dehydrogenase and its electron transfer partner cytochrome c2 (2008)

Creevey, N., McEwan, A.G., Bernhardt, P.V.

Functional analysis of the multi-copper oxidase from Legionella pneumophila (2008)

Huston, W.M., Naylor, J., Cianciotto, N.P., Jennings, M.P., McEwan, A.G.

Thermodynamic characterization of the redox centers within dimethylsulfide dehydrogenase (2008)

Creevey, N.L., McEwan, A.G., Hanson, G.R., Bernhardt, P.V.

Metal binding specificity of the MntABC permease of Neisseria gonorrhoeae and its influence on bacterial growth and interaction with cervical epithelial cells (2008)

Lim, K.H.L., Jones, C.E., Vanden Hoven, R.N., Edwards, J.L., Falsetta, M.L., Apicella, M.A., ...

Molecular ecology of a facultative swine waste lagoon. (2008)

Goh, S. H. M., Mabbett, A. N., Welch, J. P., Hall, S. J., McEwan, A. G.

Visualisation of pyrite leaching by selected thermophilic archaea: nature of microorganism-ore interactions during bioleaching (2007)

Mikkelsen, D., Kappler, U., Webb, R. I., Rasch, R., McEwan, A. G., Sly, L. I.

In this study, pyrite (FeS2) was leached by Acidianus brierleyi, Metallosphaera sedula and Sulfolobus metallicus during a 60 day experimental period. Leaching occurred over a redox potential range of...

PrrC, a Sco homologue from Rhodobacter sphaeroides, possesses thiol-disulfide oxidoreductase activity (2007)

Badrick, A. C., Hamilton, A. J., Bernhardt, P. V., Jones, C. E., Kappler, U., Jennings, M. P., ...

PrrC is a Sco homologue in Rhodobacter sphaeroides that is associated with PrrBA, a two-component signal transduction system that induces photosynthesis gene expression in response to a decrease in...

Characterization of the OxyR regulon of Neisseria gonorrhoeae (2007)

Seib, K. L., Wu, H. J., Srikhanta, Y. N., Edwards, J. L., Falsetta, M. L., Hamilton, A. J., ...

OxyR regulates the expression of the majority of H2O2 responses in Gram-negative organisms. In a previous study we reported the OxyR-dependent derepression of catalase expression in the human...

Visualisation of pyrite leaching by selected thermophilic archaea: nature of microorganism-ore interactions during bioleaching (2007)

Mikkelsen, D., Kappler, U., Webb, R. I., Rasch, R., McEwan, A. G., Sly, L. I.

In this study, pyrite (FeS2) was leached by Acidianus brierleyi, Metallosphaera sedula and Sulfolobus metallicus during a 60 day experimental period. Leaching occurred over a redox potential range of...

Application of CW and pulsed EPR, MoSophe and DFT calculations in unravelling the electronic structure of the molybdenum(V) centre in dimethylsulfoxide reductase (2007)

Noble, C. J., Drew, S., Lane, I., Benson, S., McEwan, A. G., Young, C. G., ...

Dimethylsulfoxide reductase, a bacterial molybdenum oxotransferase, belongs to the Type-III Clade of the dimethylsulfoxide (DMSO) reductase family of molybdenum enzymes and catalyses the conversion...

Application of CW and Pulsed EPR, MoSophe, and DFT Calculations in Unravelling the Electronic Structure of the Molybdenum(V) Centre in Dimethylsulfoxide Reductase (2007)

Noble, C. J., Drew, S. C., Lane, I., Benson, S., McEwan, A. G., Young, C. G., ...

Cross-talk towards the response regulator NtrC controlling nitrogen metabolism in Rhodobacter capsulatus (2006)

Drepper, T., Wiethaus, J., Giaourakis, D., Gross, S., Schubert, B., Vogt, M., ...

Rhodobacter capsulatus NtrB/NtrC two-component regulatory system controls expression of genes involved in nitrogen metabolism including urease and nitrogen fixation genes. The ntrY-ntrX genes, which...

Defenses against oxidative stress in Neisseria gonorrhoeae: A system tailored for a challenging environment (2006)

Seib, K. L., Wu, H. J., Kidd, S. P., Apicella, M. A., Jennings, M. P., McEwan, A. G.

Neisseria gonorrhoeae is a host-adapted pathogen that colonizes primarily the human genitourinary tract. This bacterium encounters reactive oxygen and reactive nitrogen species as a consequence of...

Direct electrochemically driven catalysis of bovine milk xanthine oxidase (2006)

Bernhardt, P. V., Honeychurch, M. J., McEwan, A. G.

The complex molybdoenzyme xanthine oxidase (XO) catalyses the oxidation of xanthine to uric acid. Here we report the first direct (unmediated) catalytic electrochemistry of the enzyme in the presence...

PerR controls Mn-dependent resistance to oxidative stress in Neisseria gonorrhoeae (2006)

Wu, H. J., Seib, K. L., Srikhanta, Y. N., Kidd, S. P., Edwards, J. L., Maguire, T. L., ...

In previous studies it has been established that resistance to superoxide by Neisseria gonorrhoeae is dependent on the accumulation of Mn(II) ions involving the ABC transporter, MntABC. A mutant...

Spectroscopic characterization of copper(II) binding to the immunosuppressive drug mycophenolic acid (2006)

Jones, C. E., Taylor, P. J., McEwan, A. G., Hanson, G. R.

Mycophenolic acid (MPA) is a drug that has found widespread use as an immunosuppressive agent which limits rejection of transplanted organs. Optimal use of this drug is hampered by gastrointestinal...

A multi-copper oxidase is essential for manganese oxidation and Laccase-like activity in Pedomicrobium sp. ACM 3067 (2006)

Ridge, J. P., Lin, M., Larsen, E., Fegan, M., McEwan, A. G., Sly, L. I.

Heavy metal ions and nanobiotechnology (2006)

Mabbett, A. N., Pioch, K. A., Webb, R. I., McEwan, A. G.

EPR Studies of Sulfur Centered Radicals and the Low-g Type-I Mo(V) Species in Dimtheylsulfoxide reductase Implications for Catalysis and Electron Transfer (2006)

Lane, I., Drew, S. C., Noble, C. J., McEwan, A. G., Pilbrow, J. R., Hanson, G. R.

Application of CW and Pulsed EPR, MoSophe and DFT Calculations in Unravelling the Electron Structure of the Molbdenum(V) Centre in Dimethylsulfoxide Reductase (2006)

Noble, C. J., Drew, S., Lane, I., Benson, S., McEwan, A. G., Hanson, G. R.

EPR Studies of Dimethylsulfoxide Reductase: Mo(V) Species and Sulfur Centered Radicals - their Role in Catalysis (2006)

Lane, I., Noble, C. J., McEwan, A. G., Hanson, G. R.

Microbial dimethylsulfoxide and trimethylamine-N-oxide respiration (2005)

McCrindle, S. L., Kappler, U., McEwan, A. G.

Over the last two decades, the biochemistry and genetics of dimethylsulfoxide (DMSO) and trimethylamine-N-oxide (TMAO) respiration has been characterised, particularly in Escherichia coli, marine...

NmlR of Neisseria gonorrhoeae: a novel redox responsive transcription factor from the MerR family (2005)

Kidd, S. P., Potter, A. J., Apicella, M. A., Jennings, M. P., McEwan, A. G.

A MerR-like regulator (NmlR -Neisseria merR-like Regulator) identified in the Neisseria gonorrhoeae genome lacks the conserved cysteines known to bind metal ions in characterized proteins of this...

Copper sensitivity of cueO mutants of Escherichia coli K-12 and the biochemical suppression of this phenotype (2005)

Tree, J. J., Kidd, S. P., Jennings, M. P., McEwan, A. G.

The cueO gene of Escherichia coli encodes a multi-copper oxidase, which contributes to copper tolerance in this bacterium. It was observed that a cueO mutant was highly sensitive to killing by copper...

Respiratory gene clusters of Metallosphaera sedula - differential expression and transcriptional organization (2005)

Kappler, U., Sly, L. I., McEwan, A. G.

Metallosphaera sedula is a thermoacidophilic Crenarchaeon which is capable of leaching metals from sulfidic ores. The authors have investigated the presence and expression of genes encoding...

Microbial dimethylsulfoxide and trimethylamine-N-oxide respiration (2005)

McCrindle, S. L., Kappler, U., McEwan, A. G.

Over the last two decades, the biochemistry and genetics of dimethylsulfoxide (DMSO) and trimethylamine-N-oxide (TMAO) respiration has been characterised, particularly in Escherichia coli, marine...

Microbial molybdenum-containing enzymes in respiration: Structural and functional aspects (2004)

McEwan, A. G., Kappler, U., Mc Devitt, C.

Survey of ferroxidase expression and siderophore production in clinical isolates of Pseudomonas aeruginosa (2004)

Huston, W. M., Potter, A. J., Jennings, M. P., Rello, J., Hauser, A. R., McEwan, A. G.

Ferroxidase (encoded by the mco gene), a component of a ferrous iron uptake pathway in Pseudomonas aeruginosa, was detected in all of the 35 respiratory clinical isolates surveyed; in contrast,...

Defenses against oxidative stress in Neisseria gonorrhoeae and Neisseria meningitidis: Distinctive systems for different lifestyles (2004)

Seib, K. L., Tseng, H. J., McEwan, A. G., Apicella, M. A., Jennings, M. P.

Defenses against oxidative stress are crucial for the survival of the pathogens Neisseria meningitidis and Neisseria gonorrhoeae. An Mn(II) uptake system is involved in manganese (Mn)-dependent...

Molecular analysis of the psa permease complex of Streptococcus pneumoniae (2004)

McAllister, L. J., Tseng, H. J., Ogunniyi, A. D., Jennings, M. P., McEwan, A. G., Paton, J. C.

The psaBCA locus of Streptococcus pneumoniae encodes a putative ABC Mn2+-permease complex. Downstream of the operon is psaD, which may be co-transcribed and encodes a thiol peroxidase. Previously,...

Cytochrome c(551) from Starkeya novella - Characterization, spectroscopic properties, and phylogeny of a diheme protein of the SoxAX family (2004)

Kappler, U., Aguey, F. K., Hanson, G. R., Bernhardt, P. V., McEwan, A. G.

Cytochromes from the SoxAX family have a major role in thiosulfate oxidation via the thiosulfate-oxidizing multi-enzyme system (TOMES). Previously characterized SoxAX proteins from Rhodovulum...

The critical role of tryptophan-116 in the catalytic cycle of dimethylsulfoxide reductase from Rhodobacter capsulatus (2004)

Ridge, J. P., Aguey, F. K., Bernhardt, P. V., Hanson, G. R., McEwan, A. G.

In dimethylsulfoxide reductase of Rhodobacter capsulatus tryptophan-116 forms a hydrogen bond with a single oxo ligand bound to the molybdenum ion. Mutation of this residue to phenylalanine affected...

Respiratory gene clusters of Metallosphaera sedula (2004)

Kappler, U., Sly, L. I., McEwan, A. G.

Cytochrome c551 from Starkeya novella - characterization, spectroscopic properties and phylogeny of a diheme protein of the SoxAX family (2004)

Kappler, U., Aguey, F.K., Hanson, G. R., Bernhardt, P. V., McEwan, A. G.

Molecular Sophe: An Integrated Approach to the Analysis of CW and Pulsed EPR Spectra of Biomolecules (2004)

Hanson, G. R., Noble, C. J., Mitchell, A., Benson, S., Lane, I., McEwan, A. G., ...

Direct electrochemistry of a bacterial sulfite dehydrogenase (2003)

Aguey-Zinsou, K. F., Bernhardt, P. V., Kappler, U., McEwan, A. G.

Sulfite dehydrogenase from Starkeya novella is an alphabeta heterodimer comprising a 40.6 kDa subunit (containing the Mo cofactor) and a smaller 8.8 kDa heme c subunit. The enzyme catalyses the...

Identification and in vivo characterization of PpaA, a regulator of photosystem formation in Rhodobacter sphaeroides (2003)

Gomelsky, L., Sram, J., Moskvin, O. V., Horne, I. M., Dodd, H. N., Pemberton, J. M., ...

A regulatory protein, PpaA, involved in photosystem formation in the anoxygenic phototrophic proteobacterium Rhodobacter sphaeroides has been identified and characterized in vivo. Based on the...

OxyR acts as a repressor of catalase expression in Neisseria gonorrhoeae (2003)

Tseng, H. J., McEwan, A. G., Apicella, M. A., Jennings, M. P.

It has been reported that Neisseria gonorrhoeae possesses a very high level of catalase activity, but the regulation of catalase expression has not been investigated extensively. In Escherichia coli...

A Sco homologue plays a role in defence against oxidative stress in pathogenic Neisseria (2003)

Seib, K. L., Jennings, M. P., McEwan, A. G.

Sco proteins are found in mitochondria and in a variety of oxidase positive bacteria. Although Sco is required for the formation of the Cu-A centre in a cytochrome oxidase of the aa(3) type, it was...

The Rhodobacter capsulatus dor promoter: A useful tool for the heterologous expression of redox proteins (2003)

Kappler, U., McEwan, A. G.

Probing molecular properties: Direct electrochemistry of sulfite dehydrogenase from Starkeya novella (2003)

Aguey, F.K., Bernhardt, P. V., Kappler, U., McEwan, A. G.

CW and Pulsed EPR Spectroscopy Reveal a New Structural Motif for the Active Site Mo Centre and an Unusual [4Fe-4S]+ Cluster in Dimethylsulfide Dehydrogenase (2003)

Hanson, G R, Noble, C J, McDevitt, C, McEwan, A G

The first non-turnover voltammetric response from a molybdenum enzyme: direct electroscopy of dimethylsulfoxide reductase from Rhodobacter capsulatus (2002)

Aguey, F. K., Bernhardt, P. V., McEwan, A. G., Ridge, J. P.

The first direct voltammetric response from a molybdenum enzyme under non-turnover conditions is reported. Cyclic voltammetry of dimethylsulfoxide reductase from Rhodobacter capsulatus reveals a...

Virulence of Streptococcus pneumoniae: PsaA mutants are hypersensitive to oxidative stress (2002)

Tseng, H. J., McEwan, A. G., Paton, J. C., Jennings, M. P.

psaA encodes a 37-kDa pneumococcal lipoprotein which is part of an ABC Mn(II) transport complex. Streptococcus pneumoniae D39 psaA mutants have previously been shown to be significantly less virulent...

Characterization of redox centers in dimethyl sulfide dehydrogenase from Rhodovulum sulfidophilum (2002)

McDevitt, C. A., Hanson, G. R., Noble, C. J., Cheesman, M. R., McEwan, A. G.

Dimethyl sulfide dehydrogenase from the purple phototrophic bacterium Rhodovulum sulfidophilum catalyzes the oxidation of dimethyl sulfide to dimethyl sulfoxide. Recent DNA sequence analysis of the...

A system for the heterologous expression of complex redox proteins in Rhodobacter capsulatus: characterisation of recombinant sulphite : cytochrome c oxidoreductase from Starkeya novella (2002)

Kappler, U., McEwan, A. G.

The phototrophic purple non-sulfur bacterium Rhodobacter capsulatus expresses a wide variety of complex redox proteins in response to changing environmental conditions. Here we report the...

Control of dimethylsulfoxide reductase expression in Rhodobacter capsulatus: the role of carbon metabolites and the response regulators DorR and RegA (2002)

Kappler, U., Huston, W. M., McEwan, A. G.

Regulation of the expression of dimethylsulfoxide (DMSO) reductase was investigated in the purple phototrophic bacterium Rhodobacter capsulatus. Under phototrophic, anaerobic conditions with malate...

The DMSO reductase family of microbial molybdenum enzymes; Molecular properties and role in the dissimilatory reduction of toxic elements (2002)

McEwan, A. G., Ridge, J. P., McDevitt, C. A., Hugenholtz, P.

The dimethylsulfoxide (DMSO) reductase family of molybdenum enzymes is a large and diverse group that is found in bacteria and archaea. These enzymes are characterised by a bis(molybdopterin guanine...

A comparative study of oxidative stress defence mechanisms in Neisseria meningitidis and Neisseria gonorrhoeae (2002)

Seib, K. L., Tseng, H.H., McEwan, A. G., Jennings, M. P.

Virulence factor expression in Neisseria gonorrhoeae: Regulation by manganese and the Mn(II) binding protein MntC (2002)

Tseng, H.H., Srikhanta, Y. N., McEwan, A. G., Apicella, M., Jennings, M. P.

OxyR acts as a repressor of catalase expression in Neisseria gonorrhoeae (2002)

Tseng, H.H., McEwan, A. G., Apicella, M., Jennings, M. P.

Active site heterogeneity in dimethyl sulfoxide reductase from Rhodobacter capsulatus revealed by raman spectroscopy (2001)

Bell, A. F., He, X., Ridge, J. P., Hanson, G. R., McEwan, A. G., Tonge, P. J.

Raman spectroscopy has been used to investigate the structure of the molybdenum cofactor in DMSO reductase from Rhodobacter capsulatus. Three oxidized forms of the enzyme, designated 'redox cycled',...

A role for manganese and the MntABC primary transporter in the superoxide dismutase-independent protection of Neisseria gonorrhoeae (2001)

Mcewan, A. G., Tseng, H.H., Srikhanta, Y. N., Jennings, M. P.

Xsophe and its application to the analysis of EPR spectra from the molybdoenzymes dimethylsulfoxide reductase and dimethylsulfide dehydrogenase (2001)

Noble, C. J., McDevitt, C. A., Lane, I., Griffin, M. P., Mcewan, A. G., Gates, K. E., ...

An EPR spectroscopic characterisation of dimethylsulfide dehydrogenase from rhodovulum sulfidophilum (2001)

McDevitt, C. A., Hanson, G. R., Mcewan, A. G.

Dimethylsulfide dehydrogenase from rhodovulum sulfidophilum: EPR spectroscopy and biochemical analysis reveal its place in the DMSO reductase family of molybdenum enzymes (2001)

Hanson, G. R., McDevitt, C. A., Mcewan, A. G.

Dimethylsulfide (DMS) dehydrogenase catalyses the oxidation of DMS to dimethylsulfoxide. The purified enzyme has three subunits of Mr = 94, 38 and 32 kDa and has an optical spectrum dominated by a...

Characterization of PpsR the central regulator of photosynthesis gene expression in Rhodobacter sphaeroides in response to oxygen (2000)

Dodd, H. N., Horne, I., Gomelsky, M., Kaplan, S., Pemberton, J. M., McEwan, A. G.

EPR studies of sulfur centered radicals in dimethylsulfoxide reductase (2000)

Lane, I., Hanson, G. R., McEwan, A. G., Noble, C. J., Pilbrow, J.

Sulfite: Cytochrome c oxidoreductase from Thiobacillus novellus (2000)

Kappler, U., Bennett, B., Reithmeier, J., Schwarz, G., Deutzmann, R., McEwan, A. G., ...

Direct oxidation of sulfite to sulfate occurs in various photo- and chemotrophic sulfur oxidizing microorganisms as the final step in the oxidation of reduced sulfur compounds and is catalyzed by...

Aerobic nitrate respiration in a nitrite-oxidising bioreactor (2000)

McDevitt, C., Burrell, P., Blackall, L. L., McEwan, A. G.

The ability of heterotrophic bacteria in a nitrite-oxidising bioreactor to respire with nitrate as an electron acceptor was examined. Approximately 70% of 1000 heterotrophic isolates were able to...

Manganese(II) adsorption and oxidation by whole cells and a membrane fraction of Pedomicrobium sp. ACM 3067 (1999)

Larsen, E. I., Sly, L. I., McEwan, A. G.

Heat treatment of Pedomicrobium sp. ACM 3067 enhanced the adsorption of Mn(II) to whole cells but abolished Mn(II)-oxidising activity. In whole cells, optimal Mn(II)-oxidising activity occurred at pH...

Characterisation of Dimethylsulfoxide reductase and DorC from Rhodobacter capsulatus: implications for electron transfer (1999)

Lane, I., Shaw, A., Ridge, J. P., Hanson, G. R., Mcewan, A. G.

Manganese(II) adsorption and oxidation by whole cells and a membrane fraction of Pedomicrobium sp. ACM 3067 (1999)

Larsen, E. I., Sly, L. I., McEwan, A. G.

Heat treatment of Pedomicrobium sp. ACM 3067 enhanced the adsorption of Mn(II) to whole cells but abolished Mn(II)-oxidising activity. In whole cells, optimal Mn(II)-oxidising activity occurred at pH...

Mutational analysis of the dimethysulfoxide respiratory (dor) operon of Rhodobacter capsulatus (1999)

Shaw, A., Leimkuhler, S., Klipp, W., Hanson, G. R., Mcewan, A. G.

Characterization of a molybdenum cofactor biosynthetic gene cluster in Rhodobacter capsulatus which is specific for the biogenesis of dimethylsulfoxide reductase (1999)

Solomon, P. S., Shaw, A. L., Lane, I., Hanson, G. R., Palmer, T., McEwan, A. G.

The DMSO reductase of Rhodobacter capsulatus contains a pterin molybdenum cofactor (Moco) and is located in the periplasm. DNA sequence analysis identified four genes involved in the biosynthesis of...

Reactions of dimethylsulfoxide reductase from Rhodobacter capsulatus with dimethyl sulfide and dimethyl sulfoxide: Complexities revealed by conventional and stopped-flow spectrophotometry (1999)

Adams, B., Smith, A. T., Bailey, S., McEwan, A. G., Bray, R. C.

Improved assays for the molybdenum enzyme dimethylsulfoxide reductase (DMSOR) with dimethyl sulfoxide (DMSO) and with dimethyl sulfide (DMS) as substrates are described. Maximum activity was observed...