@article {3118,
	title = {Proteome of Geobacter sulfurreducens in the presence of U(VI).},
	journal = {Microbiology (Reading)},
	volume = {160},
	year = {2014},
	month = {2014 Dec},
	pages = {2607-2617},
	abstract = {<p>Geobacter species often play an important role in the in situ bioremediation of uranium-contaminated groundwater, but little is known about how these microbes avoid uranium toxicity. To evaluate this further, the proteome of Geobacter sulfurreducens exposed to 100 {\textmu}M U(VI) acetate was compared to control cells not exposed to U(VI). Of the 1363 proteins detected from these cultures, 203 proteins had higher abundance during exposure to U(VI) compared with the control cells and 148 proteins had lower abundance. U(VI)-exposed cultures expressed lower levels of proteins involved in growth, protein and amino acid biosynthesis, as well as key central metabolism enzymes as a result of the deleterious effect of U(VI) on the growth of G. sulfurreducens. In contrast, proteins involved in detoxification, such as several efflux pumps belonging to the RND (resistance-nodulation-cell division) family, and membrane protection, and other proteins, such as chaperones and proteins involved in secretion systems, were found in higher abundance in cells exposed to U(VI). Exposing G. sulfurreducens to U(VI) resulted in a higher abundance of many proteins associated with the oxidative stress response, such as superoxide dismutase and superoxide reductase. A strain in which the gene for superoxide dismutase was deleted grew more slowly than the WT strain in the presence of U(VI), but not in its absence. The results suggested that there is no specific mechanism for uranium detoxification. Rather, multiple general stress responses are induced, which presumably enable Geobacter species to tolerate high uranium concentrations.</p>},
	keywords = {Bacterial Proteins, Gene Expression Regulation, Bacterial, Geobacter, Organometallic Compounds, Proteome},
	issn = {1465-2080},
	doi = {10.1099/mic.0.081398-0},
	author = {Orellana, Roberto and Hixson, Kim K and Murphy, Sean and Mester, T{\"u}nde and Sharma, Manju L and Lipton, Mary S and Lovley, Derek R}
}
@article {3137,
	title = {U(VI) reduction by diverse outer surface c-type cytochromes of Geobacter sulfurreducens.},
	journal = {Appl Environ Microbiol},
	volume = {79},
	year = {2013},
	month = {2013 Oct},
	pages = {6369-74},
	abstract = {<p>Early studies with Geobacter sulfurreducens suggested that outer-surface c-type cytochromes might play a role in U(VI) reduction, but it has recently been suggested that there is substantial U(VI) reduction at the surface of the electrically conductive pili known as microbial nanowires. This phenomenon was further investigated. A strain of G. sulfurreducens, known as Aro-5, which produces pili with substantially reduced conductivity reduced U(VI) nearly as well as the wild type, as did a strain in which the gene for PilA, the structural pilin protein, was deleted. In order to reduce rates of U(VI) reduction to levels less than 20\% of the wild-type rates, it was necessary to delete the genes for the five most abundant outer surface c-type cytochromes of G. sulfurreducens. X-ray absorption near-edge structure spectroscopy demonstrated that whereas 83\% {\textpm} 10\% of the uranium associated with wild-type cells correspond to U(IV) after 4 h of incubation, with the quintuple mutant, 89\% {\textpm} 10\% of uranium was U(VI). Transmission electron microscopy and X-ray energy dispersion spectroscopy revealed that wild-type cells did not precipitate uranium along pili as previously reported, but U(IV) was precipitated at the outer cell surface. These findings are consistent with those of previous studies, which have suggested that G. sulfurreducens requires outer-surface c-type cytochromes but not pili for the reduction of soluble extracellular electron acceptors.</p>},
	keywords = {Cytochromes, Fimbriae, Bacterial, Gene Deletion, Geobacter, Microscopy, Electron, Transmission, Oxidation-Reduction, Uranium, X-Ray Absorption Spectroscopy},
	issn = {1098-5336},
	doi = {10.1128/AEM.02551-13},
	author = {Orellana, Roberto and Leavitt, Janet J and Comolli, Luis R and Csencsits, Roseann and Janot, Noemie and Flanagan, Kelly A and Gray, Arianna S and Leang, Ching and Izallalen, Mounir and Mester, T{\"u}nde and Lovley, Derek R}
}
@article {414,
	title = {Supercapacitors based on c-type cytochromes using conductive nanostructured networks of living bacteria.},
	journal = {Chemphyschem},
	volume = {13},
	year = {2012},
	month = {2012 Feb},
	pages = {463-8},
	abstract = {Supercapacitors have attracted interest in energy storage because they have the potential to complement or replace batteries. Here, we report that c-type cytochromes, naturally immersed in a living, electrically conductive microbial biofilm, greatly enhance the device capacitance by over two orders of magnitude. We employ genetic engineering, protein unfolding and Nernstian modeling for in vivo demonstration of charge storage capacity of c-type cytochromes and perform electrochemical impedance spectroscopy, cyclic voltammetry and charge-discharge cycling to confirm the pseudocapacitive, redox nature of biofilm capacitance. The biofilms also show low self-discharge and good charge/discharge reversibility. The superior electrochemical performance of the biofilm is related to its high abundance of cytochromes, providing large electron storage capacity, its nanostructured network with metallic-like conductivity, and its porous architecture with hydrous nature, offering prospects for future low cost and environmentally sustainable energy storage devices.},
	keywords = {Bacteria, Biofilms, Cytochrome c Group, Dielectric Spectroscopy, Electric Capacitance, Electrodes, Geobacter, Nanostructures, Oxidation-Reduction},
	issn = {1439-7641},
	doi = {10.1002/cphc.201100865},
	author = {Malvankar, Nikhil S and Mester, T{\"u}nde and Tuominen, Mark T and Lovley, Derek R}
}
@article {427,
	title = {Biochemical characterization of purified OmcS, a c-type cytochrome required for insoluble Fe(III) reduction in Geobacter sulfurreducens.},
	journal = {Biochim Biophys Acta},
	volume = {1807},
	year = {2011},
	month = {2011 Apr},
	pages = {404-12},
	abstract = {Previous studies with Geobacter sulfurreducens have demonstrated that OmcS, an abundant c-type cytochrome that is only loosely bound to the outer surface, plays an important role in electron transfer to Fe(III) oxides as well as other extracellular electron acceptors. In order to further investigate the function of OmcS, it was purified from a strain that overproduces the protein. Purified OmcS had a molecular mass of 47015 Da, and six low-spin bis-histidinyl hexacoordinated heme groups. Its midpoint redox potential was -212 mV. A thermal stability analysis showed that the cooperative melting of purified OmcS occurs in the range of 65-82 {\textdegree}C. Far UV circular dichroism spectroscopy indicated that the secondary structure of purified OmcS consists of about 10\% α-helix and abundant disordered structures. Dithionite-reduced OmcS was able to transfer electrons to a variety of substrates of environmental importance including insoluble Fe(III) oxide, Mn(IV) oxide and humic substances. Stopped flow analysis revealed that the reaction rate of OmcS oxidation has a hyperbolic dependence on the concentration of the studied substrates. A ten-fold faster reaction rate with anthraquinone-2,6-disulfonate (AQDS) (25.2 s$^{-}${\textonesuperior}) was observed as compared to that with Fe(III) citrate (2.9 s$^{-}${\textonesuperior}). The results, coupled with previous localization and gene deletion studies, suggest that OmcS is well-suited to play an important role in extracellular electron transfer.},
	keywords = {Circular Dichroism, Cytochrome c Group, Geobacter, Heme, Iron, Kinetics, Molecular Weight, Oxidation-Reduction, Solubility},
	issn = {0006-3002},
	doi = {10.1016/j.bbabio.2011.01.003},
	author = {Qian, Xinlei and Mester, T{\"u}nde and Morgado, Leonor and Arakawa, Tsutomu and Sharma, Manju L and Inoue, Kengo and Joseph, Crisjoe and Salgueiro, Carlos A and Maroney, Michael J and Lovley, Derek R}
}
@article {418,
	title = {Tunable metallic-like conductivity in microbial nanowire networks.},
	journal = {Nat Nanotechnol},
	volume = {6},
	year = {2011},
	month = {2011 Sep},
	pages = {573-9},
	abstract = {Electronic nanostructures made from natural amino acids are attractive because of their relatively low cost, facile processing and absence of toxicity. However, most materials derived from natural amino acids are electronically insulating. Here, we report metallic-like conductivity in films of the bacterium Geobacter sulfurreducens and also in pilin nanofilaments (known as microbial nanowires) extracted from these bacteria. These materials have electronic conductivities of \~{}5~mS~cm(-1), which are comparable to those of synthetic metallic nanostructures. They can also conduct over distances on the centimetre scale, which is thousands of times the size of a bacterium. Moreover, the conductivity of the biofilm can be tuned by regulating gene expression, and also by varying the gate voltage in a transistor configuration. The conductivity of the nanofilaments has a temperature dependence similar to that of a disordered metal, and the conductivity could be increased by processing.},
	keywords = {Electric Conductivity, Geobacter, Nanowires, Transistors, Electronic},
	issn = {1748-3395},
	doi = {10.1038/nnano.2011.119},
	author = {Malvankar, Nikhil S and Vargas, Madeline and Nevin, Kelly P and Franks, Ashley E and Leang, Ching and Kim, Byoung-Chan and Inoue, Kengo and Mester, T{\"u}nde and Covalla, Sean F and Johnson, Jessica P and Rotello, Vincent M and Tuominen, Mark T and Lovley, Derek R}
}
@article {446,
	title = {Alignment of the c-type cytochrome OmcS along pili of Geobacter sulfurreducens.},
	journal = {Appl Environ Microbiol},
	volume = {76},
	year = {2010},
	month = {2010 Jun},
	pages = {4080-4},
	abstract = {Immunogold localization revealed that OmcS, a cytochrome that is required for Fe(III) oxide reduction by Geobacter sulfurreducens, was localized along the pili. The apparent spacing between OmcS molecules suggests that OmcS facilitates electron transfer from pili to Fe(III) oxides rather than promoting electron conduction along the length of the pili.},
	keywords = {Cytochromes c, Ferric Compounds, Fimbriae, Bacterial, Geobacter, Immunohistochemistry, Microscopy, Immunoelectron},
	issn = {1098-5336},
	doi = {10.1128/AEM.00023-10},
	author = {Leang, Ching and Qian, Xinlei and Mester, T{\"u}nde and Lovley, Derek R}
}
@article {445,
	title = {Purification and characterization of OmcZ, an outer-surface, octaheme c-type cytochrome essential for optimal current production by Geobacter sulfurreducens.},
	journal = {Appl Environ Microbiol},
	volume = {76},
	year = {2010},
	month = {2010 Jun},
	pages = {3999-4007},
	abstract = {Previous studies have demonstrated that Geobacter sulfurreducens requires the c-type cytochrome OmcZ, which is present in large (OmcZ(L); 50-kDa) and small (OmcZ(S); 30-kDa) forms, for optimal current production in microbial fuel cells. This protein was further characterized to aid in understanding its role in current production. Subcellular-localization studies suggested that OmcZ(S) was the predominant extracellular form of OmcZ. N- and C-terminal amino acid sequence analysis of purified OmcZ(S) and molecular weight measurements indicated that OmcZ(S) is a cleaved product of OmcZ(L) retaining all 8 hemes, including 1 heme with the unusual c-type heme-binding motif CX(14)CH. The purified OmcZ(S) was remarkably thermally stable (thermal-denaturing temperature, 94.2 degrees C). Redox titration analysis revealed that the midpoint reduction potential of OmcZ(S) is approximately -220 mV (versus the standard hydrogen electrode [SHE]) with nonequivalent heme groups that cover a large reduction potential range (-420 to -60 mV). OmcZ(S) transferred electrons in vitro to a diversity of potential extracellular electron acceptors, such as Fe(III) citrate, U(VI), Cr(VI), Au(III), Mn(IV) oxide, and the humic substance analogue anthraquinone-2,6-disulfonate, but not Fe(III) oxide. The biochemical properties and extracellular localization of OmcZ suggest that it is well suited for promoting electron transfer in current-producing biofilms of G. sulfurreducens.},
	keywords = {Binding Sites, Bioelectric Energy Sources, Cytochromes c, Electricity, Electron Transport, Geobacter, Heme, Hot Temperature, Molecular Sequence Data, Molecular Weight, Oxidation-Reduction, Protein Binding, Protein Stability, Sequence Alignment, Sequence Analysis, Protein},
	issn = {1098-5336},
	doi = {10.1128/AEM.00027-10},
	author = {Inoue, Kengo and Qian, Xinlei and Morgado, Leonor and Kim, Byoung-Chan and Mester, T{\"u}nde and Izallalen, Mounir and Salgueiro, Carlos A and Lovley, Derek R}
}
@article {483,
	title = {Genes for two multicopper proteins required for Fe(III) oxide reduction in Geobacter sulfurreducens have different expression patterns both in the subsurface and on energy-harvesting electrodes.},
	journal = {Microbiology},
	volume = {154},
	year = {2008},
	month = {2008 May},
	pages = {1422-35},
	abstract = {Previous studies have shown that Geobacter sulfurreducens requires the outer-membrane, multicopper protein OmpB for Fe(III) oxide reduction. A homologue of OmpB, designated OmpC, which is 36 \% similar to OmpB, has been discovered in the G. sulfurreducens genome. Deletion of ompC inhibited reduction of insoluble, but not soluble Fe(III). Analysis of multiple Geobacter and Pelobacter genomes, as well as in situ Geobacter, indicated that genes encoding multicopper proteins are conserved in Geobacter species but are not found in Pelobacter species. Levels of ompB transcripts were similar in G. sulfurreducens at different growth rates in chemostats and during growth on a microbial fuel cell anode. In contrast, ompC transcript levels increased at higher growth rates in chemostats and with increasing current production in fuel cells. Constant levels of Geobacter ompB transcripts were detected in groundwater during a field experiment in which acetate was added to the subsurface to promote in situ uranium bioremediation. In contrast, ompC transcript levels increased during the rapid phase of growth of Geobacter species following addition of acetate to the groundwater and then rapidly declined. These results demonstrate that more than one multicopper protein is required for optimal Fe(III) oxide reduction in G. sulfurreducens and suggest that, in environmental studies, quantifying OmpB/OmpC-related genes could help alleviate the problem that Pelobacter genes may be inadvertently quantified via quantitative analysis of 16S rRNA genes. Furthermore, comparison of differential expression of ompB and ompC may provide insight into the in situ metabolic state of Geobacter species in environments of interest.},
	keywords = {Acetates, Amino Acid Sequence, Bacterial Outer Membrane Proteins, Electrodes, Ferric Compounds, Gene Deletion, Gene Expression Profiling, Geobacter, Molecular Sequence Data, Oxidation-Reduction, Phylogeny, Sequence Alignment, Sequence Homology, Nucleic Acid, Soil Microbiology, Uranium},
	issn = {1350-0872},
	doi = {10.1099/mic.0.2007/014365-0},
	author = {Holmes, Dawn E and Mester, T{\"u}nde and O{\textquoteright}Neil, Regina A and Perpetua, Lorrie A and Larrahondo, M Juliana and Glaven, Richard and Sharma, Manju L and Ward, Joy E and Nevin, Kelly P and Lovley, Derek R}
}
@article {477,
	title = {Proteome of Geobacter sulfurreducens grown with Fe(III) oxide or Fe(III) citrate as the electron acceptor.},
	journal = {Biochim Biophys Acta},
	volume = {1784},
	year = {2008},
	month = {2008 Dec},
	pages = {1935-41},
	abstract = {The mechanisms for Fe(III) oxide reduction in Geobacter species are of interest because Fe(III) oxides are the most abundant form of Fe(III) in many soils and sediments and Geobacter species are prevalent Fe(III)-reducing microorganisms in many of these environments. Protein abundance in G. sulfurreducens grown on poorly crystalline Fe(III) oxide or on soluble Fe(III) citrate was compared with a global accurate mass and time tag proteomic approach in order to identify proteins that might be specifically associated with Fe(III) oxide reduction. A total of 2991 proteins were detected in G. sulfurreducens grown with acetate as the electron donor and either Fe(III) oxide or soluble Fe(III) citrate as the electron acceptor, resulting in 86\% recovery of the genes predicted to encode proteins. Of the total expressed proteins 76\% were less abundant in Fe(III) oxide cultures than in Fe(III) citrate cultures, which is consistent with the overall slower rate of metabolism during growth with an insoluble electron acceptor. A total of 269 proteins were more abundant in Fe(III) oxide-grown cells than in cells grown on Fe(III) citrate. Most of these proteins were in the energy metabolism category: primarily electron transport proteins, including 13 c-type cytochromes and PilA, the structural protein for electrically conductive pili. Several of the cytochromes that were more abundant in Fe(III) oxide-grown cells were previously shown with genetic approaches to be essential for optimal Fe(III) oxide reduction. Other proteins that were more abundant during growth on Fe(III) oxide included transport and binding proteins, proteins involved in regulation and signal transduction, cell envelope proteins, and enzymes for amino acid and protein biosynthesis, among others. There were also a substantial number of proteins of unknown function that were more abundant during growth on Fe(III) oxide. These results indicate that electron transport to Fe(III) oxide requires additional and/or different proteins than electron transfer to soluble, chelated Fe(III) and suggest proteins whose functions should be further investigated in order to better understand the mechanisms of electron transfer to Fe(III) oxide in G. sulfurreducens.},
	keywords = {Bacterial Proteins, Ferric Compounds, Gene Expression Regulation, Bacterial, Geobacter, Oxidation-Reduction, Proteome},
	issn = {0006-3002},
	doi = {10.1016/j.bbapap.2008.06.011},
	author = {Ding, Yan-Huai R and Hixson, Kim K and Aklujkar, Muktak A and Lipton, Mary S and Smith, Richard D and Lovley, Derek R and Mester, T{\"u}nde}
}
@article {496,
	title = {Evidence that OmcB and OmpB of Geobacter sulfurreducens are outer membrane surface proteins.},
	journal = {FEMS Microbiol Lett},
	volume = {277},
	year = {2007},
	month = {2007 Dec},
	pages = {21-7},
	abstract = {The c-type cytochrome (OmcB) and the multicopper protein (OmpB) required for Fe(III) oxide reduction by Geobacter sulfurreducens were predicted previously to be outer membrane proteins, but it is not clear whether they are positioned in a manner that permits the interaction with Fe(III). Treatment of whole cells with proteinase K inhibited Fe(III) reduction, but had no impact on the inner membrane-associated fumarate reduction. OmcB was digested by protease, resulting in a smaller peptide. However, immunogold labeling coupled with transmission electron microscopy did not detect OmcB, suggesting that it is only partially exposed on the cell surface. In contrast, OmpB was completely digested with protease. OmpB was loosely associated with the cell surface as a substantial portion of it was recovered in the culture supernatant. Immunogold labeling demonstrated that OmpB associated with the cell was evenly distributed on the cell surface rather than localized to one side of the cell like the conductive pili. Although several proteins required for Fe(III) oxide reduction are shown to be exposed on the outer surface of G. sulfurreducens, the finding that OmcB is also surface exposed is the first report of a protein required for optimal Fe(III) citrate reduction at least partially accessible on the cell surface.},
	keywords = {Bacterial Outer Membrane Proteins, Cell Membrane, Cytochromes c, Ferric Compounds, Geobacter, Microscopy, Electron, Transmission, Oxidation-Reduction, Peptide Hydrolases},
	issn = {0378-1097},
	doi = {10.1111/j.1574-6968.2007.00915.x},
	author = {Qian, Xinlei and Reguera, Gemma and Mester, T{\"u}nde and Lovley, Derek R}
}
@article {518,
	title = {The proteome of dissimilatory metal-reducing microorganism Geobacter sulfurreducens under various growth conditions.},
	journal = {Biochim Biophys Acta},
	volume = {1764},
	year = {2006},
	month = {2006 Jul},
	pages = {1198-206},
	abstract = {The proteome of Geobacter sulfurreducens, a model for the Geobacter species that predominate in many Fe(III)-reducing subsurface environments, was characterized with ultra high-pressure liquid chromatography and mass spectrometry using accurate mass and time (AMT) tags as well as with more traditional two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Cells were grown under six different growth conditions in order to enhance the potential that a wide range of genes would be expressed. The AMT tag approach was able to identify a much greater number of proteins than could be detected with the 2-D PAGE approach. With the AMT approach over 3,000 gene products were identified, representing about 90\% of the total predicted gene products in the genome. A high proportion of predicted proteins in most protein role categories were detected; the highest number of proteins was identified in the hypothetical protein role category. Furthermore, 91 c-type cytochromes of 111 predicted genes in the G. sulfurreducens genome were identified. Differences in the abundance of cytochromes and other proteins under different growth conditions provided information for future functional analysis of these proteins. These results demonstrate that a high percentage of the predicted proteins in the G. sulfurreducens genome are produced and that the AMT tag approach provides a rapid method for comparing differential expression of proteins under different growth conditions in this organism.},
	keywords = {Bacterial Proteins, Bacteriological Techniques, Chromatography, High Pressure Liquid, Cytochrome c Group, Electrophoresis, Gel, Two-Dimensional, Ferric Compounds, Fumarates, Geobacter, Peptide Fragments, Proteome, Spectrometry, Mass, Electrospray Ionization},
	issn = {0006-3002},
	doi = {10.1016/j.bbapap.2006.04.017},
	author = {Ding, Yan-Huai R and Hixson, Kim K and Giometti, Carol S and Stanley, Ann and Esteve-N{\'u}{\~n}ez, Abraham and Khare, Tripti and Tollaksen, Sandra L and Zhu, Wenhong and Adkins, Joshua N and Lipton, Mary S and Smith, Richard D and Mester, T{\"u}nde and Lovley, Derek R}
}
@article {517,
	title = {A putative multicopper protein secreted by an atypical type II secretion system involved in the reduction of insoluble electron acceptors in Geobacter sulfurreducens.},
	journal = {Microbiology},
	volume = {152},
	year = {2006},
	month = {2006 Aug},
	pages = {2257-64},
	abstract = {Extracellular electron transfer onto Fe(III) oxides in Geobacter sulfurreducens is considered to require proteins that must be exported to the outer surface of the cell. In order to investigate this, the putative gene for OxpG, the pseudopilin involved in a type II general secretion pathway of Gram-negative bacteria, was deleted. The mutant was unable to grow with insoluble Fe(III) oxide as the electron acceptor. Growth on soluble Fe(III) was not affected. An analysis of proteins that accumulated in the periplasm of the oxpG mutant, but not in the wild-type, led to the identification of a secreted protein, OmpB. OmpB is predicted to be a multicopper protein, with highest homology to the manganese oxidase, MofA, from Leptothrix discophora. OmpB contains a potential Fe(III)-binding site and a fibronectin type III domain, suggesting a possible role for this protein in accessing Fe(III) oxides. OmpB was localized to the membrane fraction of G. sulfurreducens and in the supernatant of growing cultures, consistent with the type II secretion system exporting OmpB. A mutant in which ompB was deleted had the same phenotype as the oxpG mutant, suggesting that the failure to export OmpB was responsible for the inability of the oxpG-deficient mutant to reduce Fe(III) oxide. This is the first report that proposes a role for a multicopper oxidase-like protein in an anaerobic organism. These results further emphasize the importance of outer-membrane proteins in Fe(III) oxide reduction and suggest that outer-membrane proteins other than c-type cytochromes are required for Fe(III) oxide reduction in Geobacter species.},
	keywords = {Bacterial Outer Membrane Proteins, Electron Transport, Ferric Compounds, Fimbriae Proteins, Geobacter, Manganese Compounds, Mutation, Oxidation-Reduction, Oxides},
	issn = {1350-0872},
	doi = {10.1099/mic.0.28864-0},
	author = {Mehta, Teena and Childers, Susan E and Glaven, Richard and Lovley, Derek R and Mester, T{\"u}nde}
}
@article {533,
	title = {Characterization of citrate synthase from Geobacter sulfurreducens and evidence for a family of citrate synthases similar to those of eukaryotes throughout the Geobacteraceae.},
	journal = {Appl Environ Microbiol},
	volume = {71},
	year = {2005},
	month = {2005 Jul},
	pages = {3858-65},
	abstract = {Members of the family Geobacteraceae are commonly the predominant Fe(III)-reducing microorganisms in sedimentary environments, as well as on the surface of energy-harvesting electrodes, and are able to effectively couple the oxidation of acetate to the reduction of external electron acceptors. Citrate synthase activity of these organisms is of interest due to its key role in acetate metabolism. Prior sequencing of the genome of Geobacter sulfurreducens revealed a putative citrate synthase sequence related to the citrate synthases of eukaryotes. All citrate synthase activity in G. sulfurreducens could be resolved to a single 49-kDa protein via affinity chromatography. The enzyme was successfully expressed at high levels in Escherichia coli with similar properties as the native enzyme, and kinetic parameters were comparable to related citrate synthases (kcat= 8.3 s(-1); Km= 14.1 and 4.3 microM for acetyl coenzyme A and oxaloacetate, respectively). The enzyme was dimeric and was slightly inhibited by ATP (Ki= 1.9 mM for acetyl coenzyme A), which is a known inhibitor for many eukaryotic, dimeric citrate synthases. NADH, an allosteric inhibitor of prokaryotic hexameric citrate synthases, did not affect enzyme activity. Unlike most prokaryotic dimeric citrate synthases, the enzyme did not have any methylcitrate synthase activity. A unique feature of the enzyme, in contrast to citrate synthases from both eukaryotes and prokaryotes, was a lack of stimulation by K+ ions. Similar citrate synthase sequences were detected in a diversity of other Geobacteraceae members. This first characterization of a eukaryotic-like citrate synthase from a prokaryote provides new insight into acetate metabolism in Geobacteraceae members and suggests a molecular target for tracking the presence and activity of these organisms in the environment.},
	keywords = {Amino Acid Sequence, Citrate (si)-Synthase, Culture Media, Deltaproteobacteria, DNA, Bacterial, Eukaryotic Cells, Geobacter, Kinetics, Molecular Sequence Data, Phylogeny, Sequence Analysis, DNA},
	issn = {0099-2240},
	doi = {10.1128/AEM.71.7.3858-3865.2005},
	author = {Bond, Daniel R and Mester, T{\"u}nde and Nesb{\o}, Camilla L and Izquierdo-Lopez, Andrea V and Collart, Frank L and Lovley, Derek R}
}
