growth of desulfovibrio in lactate or ethanol media low in sulfate in association with h2-utilizing methanogenic the analysis of an ethanol-co(2) enrichment of bacteria from an anaerobic sewage digestor, a strain tentatively identified as desulfovibrio vulgaris and an h(2)-utilizing methanogen resembling methanobacterium formicicum were isolated, and they were shown to represent a synergistic association of two bacterial species similar to that previously found between s organism and methanobacterium strain moh isolated from methanobacillus omelianskii. in lowsulfate media, the desulfovibrio produced ac ...1977879775
a structural model of rubredoxin from desulfovibrio vulgaris at 2 a resolution. 1977881725
dithionite reduction in the presence of a tetrapyrrole-containing fraction from the desulfoviridin of desulfovibrio gigas.low-molecular-weight fractions obtained from the desulfoviridin of d. gigas and from the growth medium of desulfovibrio sp. 10455 promoted the reduction of sodium dithionite to sulphide in the presence of reduced methylviologen. these fractions contained a tetrapyrrole of the isobacteriochlorin type which was not complexed with iron, nor was it complexed with protein. the observations are discussed in relation to the function of sulphite reductases in the sulphate-reducing bacteria.1977901305
study of two forms of ferredoxin from desulfovibrio gigas by differential pulse polarography. 1977907681
the mass spectrometry of iso and anteiso monoenoic fatty acids. 1977909359
bisulfite reductase of desulfovibrio vulgaris: explanation for product formation.bisulfite reductase, purified from desulfovibrio vulgaris, was coupled with the pyruvate phosphoroclastic reaction. moderate to low reducing conditions resulted in the formation of trithionate; however, when the concentration of reductant was high, a mixture of trithionate and thiosulfate was formed. sulfide was also a detectable product, but only when the concentration of bisulfite was low. flavodoxin mediated native coupling between bisulfite reductase and the phosphoroclastic reaction. a mode ...1977914772
the taxonomy of some new isolates of dissimilatory sulfate-reducing bacteria.the interrelationships between 92 isolates of sporing and non-sporing sulfate-reducing bacteria were determined. of the 116 biochemical and physiological characteristics examined, only 25 were useful for discrimination of groups. responses to most of the test were negative. a similarity coefficient and a principal component factor analysis of these data were made. the deoxyribonucleic acids buoyant densities (dna) from all strains and the electrophoretic properties of adenylylsulfotransferase (a ...1977922597
influence of the concentration of phosphorus, potassium, calcium and iron compounds on the microbial reduction of the reduction process of sulphates by desulfovibrio desulfuricans suitable concentration of mineral salts plays an important role. in particular, different k2hpo4, cacl2 and fe(nh4)2(so4)2 content in the reaction medium has an observable effect on the reduction degree (x'), the induction time (t0) and the reduction rate constant (k). these data were recorded for 9 liquid media characterized by different content of mineral salts. the reaction rate constants were calculated for the reduction pr ...1976937089
the amino acid sequence of rubredoxin from the sulfate reducing bacterium, desulfovibrio gigas. 1976938515
purification and properties of a four iron-four sulfur protein from a pseudomonas species.we have isolated an iron-sulfur proteins from a pseudomonas species grown on glucose. this protein has different properties from the two known iron-sulfur proteins isolated from other pseudomonas species: rubredoxin and putidaredoxin. the iron-sulfur protein was purified to homogeneity by deae-cellulose column chromatography and sephadex g-75 gel filtration. the absorption spectrum of the oxidized iron-sulfur protein shows a peak at 283 nm with shoulders at about 290, 320, and 410 nm. the protei ...1976956144
structural studies of electron transfer proteins from sulfate reducing bacteria: the amino acid sequence of two rubredoxins isolated from desulfovibrio vulgaris and desulfovibrio gigas. 1976961540
purification of a unique bisulfite-reducing enzyme from desulfovibrio vulgaris. 1976971307
bouyant density, conversion formulae, and the mole percent guanosine + cytosine content of desulfovibrio sp.a reevaluation of the original buoyant density conversion formula used to calculate the molar percentage guanosine + cytosine (% g + c) contents of the accepted species of genus desulfovibrio has been undertaken. it would appear that the formula used gives values 4-5% lower than those obtained using formulae more generally cited in modern literature. recalculations of % g + c content values for lesulfovibrio dna are presented using the formulae of three different workers, and are compared with t ...1976974922
desulfovibrio of the sheep rumen.a sulfate-reducing bacterium has been isolated in pure culture from sheep rumen contents. its properties agree in all respects tested with those ascribed to desulfovibrio desulfuricans. the populations observed (about 10(8)/ml) are sufficient to account for published rates of ruminal sulfide production.1976984832
purification, characterization and biological activity of three forms of ferredoxin from the sulfate-reducing bacterium desulfovibrio gigas.three forms of ferredoxin fdi, fdi', and fdii have been isolated from desulfovibrio gigas, a sulfate reducer. they are separated by a combination of deae-cellulose and gel filtration chromatographic procedures. fdi and fdi' present a slight difference in isoelectric point which enables the separation of the two forms over deae-cellulose, while fdii is easily separated from the two other forms by gel filtration. the three forms have the same amino acid composition and are isolated in different ag ...1976990295
amino acid sequence of a four-iron-four-sulphur ferredoxin isolated from bacillus stearothermophilus.1. the primary structure of a 4fe-4s ferredoxin from bacillus stearothermophilus was determined and shown to consist of a single polypeptide chain of 81 amino acid residues. the molecular weight of the holoprotein is about 9120. 2. there are only four cysteine residues in the molecule; three of these are located near the n-terminus as a cys-x-x-cys-x-x-cys segment, and the fourth cysteine residue is followed by a proline and located in the c-terminal half. 3. the fe-s chromophore in b. stearothe ...1976999643
some comparisons between two crystallized anaerobic bacterial ruberdoxins from desulfovibrio gigas and d. vulgaris. 19761003467
[mesophilic rod-like nonsporeforming bacterium reducing sulfates].a pure culture of a new organism, strain x, reducing sulphates is described. according to its morphological, physiological and biochemical properties, the organism is classed as a new species. desulfovibrio baculatus nov. sp. the cells have the shape of short rods, 1.3x0.6 mcm, with a polar flagellum 0.021 mcm thick. it is an obligate anaerobic culture growing on media only in the presence of sulphates at the account of sodium salts of lactic, pyruvic and malic acids and also in the presence of ...19761004270
are thiosulfate and trithionate intermediates in dissimilatory sulfate reduction?the fate of 35-s during anaerobic metabolism of [35-s]sulfate, [35-s]thiosulfate, and [35-s]sulfate plus unlabeled thiosulfate by washed cell suspensions of desulfovibrio spp, and of [35-s]thiosulfate by growing d. desulfuricans was examined. the results appear to be inconsistent with the hypothesis that thiosulfate is an intermediate in sulfate reduction. since thiosulfate was produced from trithionate, the latter is also unlikely to be an intermediate in the reduction pathway. extracts of d. d ...19751141200
isolation and characterization of an ornithine-containing lipid from desulfovibrio gigas.the isolation and characterization of an ornithine-containing lipid obtained from desulfovibrio gigas are reported. the general structure for this aminolipid is represented by nh2-ch2-(ch)2-chnh(co-ch2ch(o-cor2)-r1)-cooh, where r1 represents 3-hydroxy palmitate linked through an amide bond to the alpha-amino group of ornithine, and r2 represents a complex variety of fatty acids esterified to the hydroxyl group of 3-hydroxy palmitate. fatty acids characterized were n-c14:0 (21%), iso-c14:0 (14%) ...19751150624
keto acid metabolism in desulfovibrio.four strains of desulfovibrio each excreted pyruvate to a constant level during growth; it was re-absorbed when the substrate (lactate) was exhausted. malate, succinate, fumarate and malonate also accumulated during growth. one of the strains (hildenborough) excreted alpha-ketoglutarate as well as pyruvate when incubated in nitrogen-free medium; the former was re-absorbed on addition of nh4cl. in a low-lactate nitrogen-free medium, strain hildenborough rapidly re-absorbed the pyruvate initially ...19751194893
fractionation of sulfur isotopes by continuous cultures of desulfovibrio desulfuricans.sulfur isotope effects observed in lactate-limited continuous cultures of desulfovibrio desulfuricans were, in general, similar to those reported for sulfate reduction by washed cells and batch cultures. there was a trend towards higher fractionation at low growth rates.19751201506
effect of the concentration of nitrogen compounds on microbial reduction of sulphates.a change of the n/s ratio in the reaction medium affects the degree of the microbial reduction of sulphates to sulphides (x'). the time interval between the initial and the log phase of the process (t0) also varies, depending on the n/s ratio. it was demonstrated that optimal reduction conditions by the studied strain of desulfovibrio desulphuricans exist in media of n/s=0.33.19751227256
purification and properties of sulfoacetaldehyde sulfo-lyase, a thiamine pyrophosphate-dependent enzyme forming sulfite and acetate.sulfoacetaldehyde sulfo-lyase, which decomposes sulfoacetaldehyde to sulfite and acetate, was extracted from a bacterium grown on taurine, and purified, and characterized. a method for assay of enzyme activity was devised on formation of a bisulfite adduct with benzaldehyde. the enzyme was purified 14-fold from an extract of cells grown on taurine and appeared homogeneous on disc-electrophoresis. the molecular weight of the enzyme was estimated to be 85,000 by gel filtration. the enzyme required ...19751228172
[numerical taxonomy of the genus desulfovibrio by group analysis].the desulfovibrio genus has a particular interest because it includes the microorganisms connected with the corrosion produced microbiologically. the taxonomy of the genus shows disadvantages due to its metabolical and physiological characteristics. in this paper, 14 strains of the desulfovibrio type were studied from the metabolical point of view. numeric taxonomy was carried out according to the group analysis method, using and comparing the change possibilities of the method. the consensus me ...19921302868
[analysis of principal coordinates and factorial correspondence analysis applied to the taxonomy of type strains of desulfovibrio].bacterial taxonomy using mathematical methods can be carried out with different techniques. two techniques are used in this paper: analysis of principal coordinates and factor analysis of correspondences. the first one allows 2 and 3 dimension graphs of bacteria, thus showing their relationship considering proximity. the second one gives new data because it is an analysis which allows to connect bacteria to the reactions which identify them. in order to carry out these analyses 14 strains of the ...19921302869
[the microbiological purification of industrial sulfur-containing sewage]. 19921303100
direct spectroscopic evidence for the presence of a 6fe cluster in an iron-sulfur protein isolated from desulfovibrio desulfuricans (atcc 27774)a novel iron-sulfur protein was purified from the extract of desulfovibrio desulfuricans (atcc 27774) to homogeneity as judged by polyacrylamide gel electrophoresis. the purified protein is a monomer of 57 kda molecular mass. it contains comparable amounts of iron and inorganic labile sulfur atoms and exhibits an optical spectrum typical of iron-sulfur proteins with maxima at 400, 305, and 280 nm. mössbauer data of the as-isolated protein show two spectral components, a paramagnetic and a diamag ...19921311311
mössbauer study of the native, reduced and substrate-reacted desulfovibrio gigas aldehyde oxido-reductase.the desulfovibrio gigas aldehyde-oxido-reductase contains molybdenum and iron-sulfur clusters. mössbauer spectroscopy was used to characterize the iron-sulfur clusters. spectra of the enzyme in its oxidized, partially reduced and benzaldehyde-reacted states were recorded at different temperatures and applied magnetic fields. all the iron atoms in d. gigas aldehyde oxido-reductase are organized as [2fe-2s] clusters. in the oxidized enzyme, the clusters are diamagnetic and exhibit a single quadrup ...19921311679
mössbauer characterization of the tetraheme cytochrome c3 from desulfovibrio baculatus (dsm 1743). spectral deconvolution of the heme components.mössbauer spectroscopy was used to study the tetraheme cytochrome c3 from desulfovibrio baculatus (dsm 1743). samples with different degrees of reduction were prepared using a redoxtitration technique. in the reduced cytochrome c3, all four hemes are reduced and exhibit diamagnetic mössbauer spectra typical for low-spin ferrous hemes (s = 0). in the oxidized protein, the hemes are low-spin ferric (s = 1/2) and exhibit overlapping magnetic mössbauer spectra. a method of differential spectroscopy ...19921311680
biochemical and spectroscopic characterization of the high molecular weight cytochrome c from desulfovibrio vulgaris hildenborough expressed in desulfovibrio desulfuricans g200.the gene of high molecular weight, multiheme cytochrome c (hmc) from the sulfate-reducing bacterium desulfovibrio vulgaris hildenborough has been overexpressed in desulfovibrio desulfuricans g200. the recombinant protein has been purified. its molecular weight (65,600), amino acid composition, and nh2-terminal sequence were found to be identical to those of the wild-type protein. the recombinant protein has been spectroscopically characterized (optical spectrum, epr, circular dichroism) and comp ...19921313289
the nickel site in active desulfovibrio baculatus [nifese] hydrogenase is diamagnetic. multifield saturation magnetization measurement of the spin state of ni(ii).the magnetic properties of the nickel(ii) site in active desulfovibrio baculatus (dsm 1743) [nifese] hydrogenase have been measured using the multifield saturation magnetization technique. the periplasmic [nifese] hydrogenase was isolated from bacteria grown in excess selenium in the presence of 57fe. saturation magnetization data were collected at three fixed fields (1.375, 2.75, 5.5 tesla) over the temperature range from 2 to 100 k. mössbauer and epr spectroscopies were used to characterize th ...19921313795
potentiometric and voltammetric investigations of h2/h+ catalysis by periplasmic hydrogenase from desulfovibrio gigas immobilized at the electrode surface in an amphiphilic bilayer assembly.interactions of an enzyme with an organized amphipilic bilayer are explored as a general means of enzyme immobilization in electroenzymatic systems. immobilization of desulfovibrio gigas hydrogenase at the electrode surface involves hydrophobic interactions of the enzyme with the bilayer assembly consisting of octadecyltrichlorosilane and octadecylviologen (c18mv2+) molecules. due to a hydrophobic character of the enzyme, these interactions direct the enzyme to occupy a central position in the b ...19921316088
partial purification and characterization of the first hydrogenase isolated from a thermophilic sulfate-reducing bacterium.a soluble [nife] hydrogenase has been partially purified from the obligate thermophilic sulfate-reducing bacterium thermodesulfobacterium mobile. a 17% purification yield was obtained after four chromatographic steps and the hydrogenase presents a purity index (a398 nm/a277 nm) equal to 0.21. this protein appears to be 75% pure on sds-gel electrophoresis showing two major bands of molecular mass around 55 and 15 kda. this hydrogenase contains 0.6-0.7 nickel atom and 7-8 iron atoms per mole of en ...19921317168
purification and biochemical characterization of a putative [6fe-6s] prismane-cluster-containing protein from desulfovibrio vulgaris (hildenborough).a novel iron-sulfur protein has been isolated from the sulfate-reducing bacterium desulfovibrio vulgaris (hildenborough). it is a stable monomeric protein, which has a molecular mass of 52 kda, as determined by sedimentation-equilibrium centrifugation. analysis of the metal and acid-labile sulfur content of the protein revealed the presence of 6.3 +/- 0.4 fe/polypeptide and 6.2 +/- 0.7 s2-/polypeptide. non-iron transition metals, heme, flavin and selenium were absent. combining these data with t ...19921318832
multi-frequency epr and high-resolution mössbauer spectroscopy of a putative [6fe-6s] prismane-cluster-containing protein from desulfovibrio vulgaris (hildenborough). characterization of a supercluster and superspin model protein.the putative [6fe-6s] prismane cluster in the 6-fe/s-containing protein from desulfovibrio vulgaris, strain hildenborough, has been enriched to 80% in 57fe, and has been characterized in detail by s-, x-, p- and q-band epr spectroscopy, parallel-mode epr spectroscopy and high-resolution 57fe mössbauer spectroscopy. in epr-monitored redox-equilibrium titrations, the cluster is found to be capable of three one-electron transitions with midpoint potentials at ph 7.5 of +285, +5 and -165 mv. as the ...19921318833
epr and redox properties of desulfovibrio vulgaris miyazaki hydrogenase: comparison with the ni-fe enzyme from desulfovibrio gigas.we have carried out a detailed redox titration monitored by epr on the hydrogenase from desulfovibrio vulgaris miyazaki. typical 3fe and nickel signals have been observed, which are very similar to those given by desulfovibrio gigas hydrogenase in all the characteristic redox states of the enzyme. this confirms that d. vulgaris miyazaki hydrogenase is a ni-fe enzyme closely related to that from d. gigas, as was recently proposed on the basis of sequence comparisons (deckers, h.m., wilson, f.r. a ...19921321673
the ph in reversed micelles as imposed by the dihydrogen/proton redox couple and indicated by viologens and cytochrome c3 using hydrogenase as redox catalyst.the ph values in reversed micelles were measured, making use of the hydrogenase enzyme as redox catalyst short-circuiting the viologen oxidized/semiquinone redox states. the hydrogenases from desulfovibrio vulgaris (hildenborough) and from megasphaera elsdenii were applied. the observed ph values in reversed micelles were not dependent on the type of hydrogenase. two cationic [cetyltrimethylammonium bromide and dodecylammonium propionate (dap)] and two anionic sodiumdodecyl sulphate, sodium di(e ...19921321716
non-equivalent natures of the coordinated imidazole rings of cytochrome c3 from d. vulgaris miyazaki f as studied by 1h nmr.all of the c2 proton signals of the coordinated histidine residues in the 1h nmr spectrum of cytochrome c3 from d. vulgaris miyazaki f were assigned by specific deuteration. they appeared at extremely high fields and scattered in a wide range from -4 to -22 ppm. this clearly shows that the chemical properties of the imidazole groups are quite different from one another. the extremely high-field shift of the c2 signal indicates that some of them must carry the imidazolate-like nature to some exte ...19921324187
site-directed mutagenesis of tetraheme cytochrome c3. modification of oxidoreduction potentials after heme axial ligand replacement.the nature of the axial ligands of a heme group is an important factor in maintaining the oxidation-reduction potential of a c-type cytochrome. cytochrome c3 from desulfovibrio vulgaris hildenborough contains four bis-histidinyl coordinated hemes with low oxidation-reduction potentials. site-directed mutagenesis was used to generate a mutant in which histidine 70, the sixth axial ligand of heme 4, has been replaced by a methionine. the mutant protein was expressed in desulfovibrio desulfuricans ...19921324913
sequential nmr resonance assignment and secondary structure of ferrocytochrome c553 from desulfovibrio vulgaris hildenborough.two-dimensional nuclear magnetic resonance spectroscopy was used to assign the proton resonances of ferrocytochrome c553 from desulfovibrio vulgaris hildenbourough at 37 degrees c and ph = 5.9. only a few side-chain protons were not identified because of degeneracy or overlap. the spin systems of the 79 amino acids were identified by dqf-cosy and hohaha spectra in h2o and d2o. sequential assignments were obtained from noesy connectivities between adjacent amide, c alpha h, and c beta h protons. ...19921326323
revision of the haem-core architecture in the tetraheam cytochrome c3 from desulfovibrio baculatus by two-dimensional 1h nmr.the haem-core architecture in cytochrome c3 isolated from desulfovibrio baculatus (norway 4) was probed using two-dimensional 1h nmr. interhaem connectivities detected in noe spectroscopy experiments performed at short mixing times are incompatible with the structure of the protein determined by x-ray crystallography, but agree instead with the haem arrangement found in cytochrome c3 from desulfovibrio vulgaris (miyazaki). these experiments show unequivocally that the relative orientation of the ...19921327772
further characterization of the [fe]-hydrogenase from desulfovibrio desulfuricans atcc 7757.the properties of the periplasmic hydrogenase from desulfovibrio desulfuricans atcc 7757, previously reported to be a single-subunit protein [glick, b. r., martin, w. g., and martin, s. m. (1980) can. j. microbiol. 26, 1214-1223] were reinvestigated. the pure enzyme exhibited a molecular mass of 53.5 kda as measured by analytical ultracentrifugation and was found to comprise two different subunits of 42.5 kda and 11 kda, with serine and alanine as n-terminal residues, respectively. the n-termina ...19921327776
iron-sulphur clusters with labile metal ions.a study has been carried out of the redox-linked metal ion uptake processes of the iron-sulphur cluster [3fe-4s] in the bacterial ferredoxin, fd iii from desulphovibrio africanus using a combination of electron paramagnetic resonance (epr) and low-temperature magnetic circular dichroism (mcd) spectroscopy and direct, unmediated electrochemistry of the fd in a film deposited at a pyrolytic graphite electrode. reduction of the three-iron cluster is required before a divalent metal ion becomes boun ...19921331321
anaerobic degradation of 1,2-propanediol by a new desulfovibrio strain and d. alcoholovorans.a sulfate-reducing bacterium, strain hdv, was isolated from the anoxic soil of a ricefield using lactate as electron donor. cells were gram-negative, motile, nonsporulating curved rods, with single polar flagella. substrates were incompletely oxidized to acetate and included glycerol, 1,2- and 1,3-propanediol. sulfate, sulfite, thiosulfate, elemental sulfur, fumarate, maleate, and malate were utilized as electron acceptors. pyruvate, fumarate, maleate, malate and dihydroxyacetone were fermented. ...19921332638
reduction kinetics of the four hemes of cytochrome c3 from desulfovibrio vulgaris by flash photolysis.the reduction of the tetraheme cytochrome c3 (from desulfovibrio vulgaris, strains miyazaki f and hildenbourough) by flavin semiquinone and reduced methyl viologen follows a monophasic kinetic profile, even though the four hemes do not have equivalent reduction potentials. rate constants for reduction of the individual hemes are obtained subsequent to incrementally reducing the cytochrome by phototitration. the dependence of each rate constant on the reduction potential difference between the he ...19921332780
assignment of the redox potentials to the four haems in desulfovibrio vulgaris cytochrome c3 by 2d-nmr.using 2d-nmr the four haems of desulfovibrio vulgaris (hildenborough) cytochrome c3 within the x-ray structure were fully cross assigned according to their redox potential. the strategy used was based on a complete network of chemical exchange connectivities between the nmr signals obtained for all oxidation levels to the corresponding ones in the fully reduced spectrum [1992, eur. j. biochem., in press]. this unequivocal cross-assignment disagrees with earlier results obtained for the similar p ...19921333991
crystallization and preliminary crystallographic study of an octa-heme cytochrome c3 from desulfovibrio desulfuricans octa-heme cytochrome c3, isolated as a dimeric molecule of about 30 kda from the anaerobic bacteria desulfovibro desulfuricans norway, has been crystallized in a form suitable for atomic resolution x-ray structural investigations. the crystals are trigonal, space group p3(1)21 (or its enantiomorph p3(2)21), with cell dimensions: a = b = 72.9 a c = 62.7 a. the asymmetric unit contains most probably one monomer and a solvent content of about 60%. under this assumption, the crystallographic 2-fo ...19921335087
reactivity of [fe] and [ni-fe-se] hydrogenases with their oxido-reduction partner: the tetraheme cytochrome order to understand the electron transfer mechanisms for the [fe] and [ni-fe] hydrogenases, a kinetic study of cytochrome c3 reduction has been undertaken. cyclic voltammetry and controlled-potential amperometry techniques have been used to investigate the intermolecular electron-transfer reaction between cytochrome c3 and [fe] hydrogenase from desulfovibrio vulgaris hildenborough. electron-transfer cross-reactions between [fe] or [ni-fe-se] hydrogenase and cytochrome c3 from desulfovibrio vu ...19921335243
structural studies of desulfovibrio vulgaris ferrocytochrome c3 by two-dimensional nmr.two-dimensional nmr has been used to make specific assignments for the four haems in desulfovibrio vulgaris (hildenborough) ferrocytochrome c3 and to determine their haem core architecture. the nmr signals from the haem protons were assigned according to type using two-dimensional nmr experiments which led to four sets of signals, one for each of the haems. specific assignments were obtained by calculating the ring current shifts which arise from other haems and aromatic residues. observation of ...19921336461
overproduction of prismane protein in desulfovibrio vulgaris (hildenborough): evidence for a second s = 1/2-spin system in the one-electron reduced state.the gene encoding the prismane protein from desulfovibrio vulgaris (hildenborough) was inserted into broad-host-range vector psup104. the recombinant plasmid, pjsp104, was transferred to d. vulgaris by conjugal plasmid transfer. in the transconjugant d. vulgaris cells the prismane protein was 25-fold overproduced. the overproduced prismane protein was characterized by molecular mass, isoelectric point, iron content and spectroscopical properties. both the iron content and the ultraviolet/visible ...19921336462
the primary structure of a protein containing a putative [6fe-6s] prismane cluster from desulfovibrio vulgaris (hildenborough).the gene encoding a protein containing a putative [6fe-6s] prismane cluster has been cloned from desulfovibrio vulgaris (hildenborough) and sequenced. the gene encodes a polypeptide composed of 553 amino acids (60,161 da). the dna-derived amino acid sequence was partly confirmed by n-terminal sequencing of the purified protein and of fragments of the protein generated by cnbr cleavage. furthermore, the c-terminal sequence was verified by digestion with carboxypeptidases a and b. the polypeptide ...19921339351
anaerobic degradation of sorbic acid by sulfate-reducing and fermenting bacteria: pentanone-2 and isopentanone-2 as byproducts.strictly anaerobic bacteria were enriched and isolated from freshwater sediment sources in the presence and absence of sulfate with sorbic acid as sole source of carbon and energy. strain woso1, a gram-negative vibrioid sulfate-reducing bacterium which was assigned to the species desulfoarculus (formerly desulfovibrio) baarsii oxidized sorbic acid completely to co2 with concomitant stoichiometric reduction of sulfate to sulfide. this strain also oxidized a wide variety of fatty acids and other o ...19911368475
trinitrotoluene (tnt) as a sole nitrogen source for a sulfate-reducing bacterium desulfovibrio sp. (b strain) isolated from an anaerobic digester.a sulfate-reducing bacterium (srb), desulfovibrio sp. (b strain), isolated from a continuous anaerobic digester (boopathy and daniels, current microbiology, 23:327-332, 1991) was found to use 2,4,6-trinitrotoluene (tnt) as sole nitrogen source. this bacterium also used nitrate, nitrite, and ammonium as nitrogen source. a long lag period was noticed when tnt or nitrite was used as nitrogen source. nitrate, nitrite and tnt also served as electron acceptor in the absence of sulfate for this bacteri ...19921368976
desulfovibrio longus sp. nov., a sulfate-reducing bacterium isolated from an oil-producing well.a novel type of sulfate-reducing bacteria with unusual morphology was isolated from an oil-producing well in the paris basin. the cells of this bacterium, strain sebr 2582t (t = type strain), are long, thin, flexible rods, contain desulfoviridin, and are physiologically similar to members of the genus desulfovibrio. on the basis of 16s rrna sequence data, this strain should be included in the genus desulfovibrio. however, strain sebr 2582t differs from other members of this genus morphologically ...19921380287
redox properties of the iron-sulfur clusters in activated fe-hydrogenase from desulfovibrio vulgaris (hildenborough).the periplasmic fe-hydrogenase from desulfovibrio vulgaris (hildenborough) contains three iron-sulfur prosthetic groups: two putative electron transferring [4fe-4s] ferredoxin-like cubanes (two f-clusters), and one putative fe/s supercluster redox catalyst (one h-cluster). combined elemental analysis by proton-induced x-ray emission, inductively coupled plasma mass spectrometry, instrumental neutron activation analysis, atomic absorption spectroscopy and colorimetry establishes that elements wit ...19921396719
synthesis and characterization of a 25-residue rubredoxin(ii)-like metalloprotein and its valine-leucine iron-sulfur metalloprotein containing the 5-12 and 35-50 residues of desulfovibrio gigas rubredoxin has been synthesized by fmoc solid phase peptide synthesis and subsequent peptide folding. a gly links the two residue chains between val-5 and glu-50. sybyl tripos structure optimization indicates only minor structural changes of the folded synthetic protein compared to the similar residue positions in the native protein. the uv-vis spectrum of the reduced synthetic protein is very similar to ...19921426256
plasmid transfer by conjugation in desulfovibrio desulfuricans.conjugational transfer of several incq plasmids from escherichia coli to the strictly anaerobic, sulfate-reducing bacterium desulfovibrio desulfuricans strain g100a was demonstrated. plasmid dna from exconjugants was visualized on agarose gels and was used to transform e. coli to the appropriate antibiotic resistances. neither transfer of incw and incp plasmids to strain g100a, nor transfer of any plasmid to d. desulfuricans strain atcc 27774 was observed. conjugation of suicide plasmids contain ...19921426989
effect of copper ions on hydrogenase activity of desulfovibrio desulfuricans. 19921441843
site-directed mutagenesis of the hydrogenase signal peptide consensus box prevents export of a beta-lactamase fusion protein.a secretion vector, pvn1, expressing the [nife] hydrogenase signal peptide of desulfovibrio vulgaris hildenborough fused to beta-lactamase from escherichia coli was constructed in order to study the unusual characteristics of hydrogenase signal peptides, which share a strictly conserved sequence, the consensus box: r-r-x-f-x-k. although the hydrogenase signal peptide-beta-lactamase fusion protein was processed much more slowly than the fusion of beta-lactamase with its own signal peptide, the sy ...19921479348
the primary structure of a protein containing a putative [6fe-6s] prismane cluster from desulfovibrio desulfuricans (atcc 27774).the gene encoding a protein containing a novel iron sulfur cluster ([6fe-6s]) has been cloned from desulfovibrio desulfuricans atcc 27774 and sequenced. an open reading frame was found encoding a 545 amino acid protein (m(r) 58,496). the amino acid sequence is highly homologous with that of the corresponding protein from d. vulgaris (hildenborough) and contains a cys-motif that may be involved in coordination of the fe-s cluster.19921511014
molecular characterization of two bacteriophages isolated from desulfovibrio vulgaris ncimb 8303 (hildenborough).a preliminary endonuclease restriction map of a bacteriophage isolated from desulfovibrio vulgaris has been established. bamhi cleaved whole phage dna into four fragments while hindiii cut the same dna into seven fragments. mapping studies succeeded in linking the four bamhi fragments into two dna segments; however, no linkage between the two segments was detected. these data imply that two phages were induced from cultures of d. vulgaris and that the two segments represented the dna from these ...19921512570
distinct redox behaviour of prosthetic groups in ready and unready hydrogenase from chromatium vinosum.the redox behaviour of the ni(iii)/ni(ii) transition in hydrogenase from chromatium vinosum is described and compared with the redox behaviour of the nickel ion in the f420-nonreducing hydrogenase from methanobacterium thermoautotrophicum. analogous to the situation in the oxidised hydrogenase of desulfovibrio gigas (fernandez, v.m., hatchikian, e.c., patil, d.s. and cammack, r. (1986) biochim. biophys. acta 883, 145-154), the c. vinosum enzyme can also exist in two forms: the 'unready' form (ep ...19921540647
nucleotide sequence of dcra, a desulfovibrio vulgaris hildenborough chemoreceptor gene, and its expression in escherichia coli.the amino acid sequence of dcra (mr = 73,000), deduced from the nucleotide sequence of the dcra gene from the anaerobic, sulfate-reducing bacterium desulfovibrio vulgaris hildenborough, indicates a structure similar to the methyl-accepting chemotaxis proteins from escherichia coli, including a periplasmic nh2-terminal domain (mr = 20,700) separated from the cytoplasmic cooh-terminal domain (mr = 50,300) by a hydrophobic, membrane-spanning sequence of 20 amino acid residues. the sequence homology ...19921548224
the third subunit of desulfoviridin-type dissimilatory sulfite addition to the 50-kda (alpha) and 40-kda (beta) subunits, an 11-kda polypeptide has been discovered in highly purified desulfovibrio vulgaris (hildenborough) dissimilatory sulfite reductase. this is in contrast with the hitherto generally accepted alpha 2 beta 2 tetrameric subunit composition. purification, high-ionic-strength gel-filtration, native electrophoresis and isoelectric focussing do not result in dissociation of the 11-kda polypeptide from the complex. densitometric scanning of sd ...19921555572
reduction of uranium by desulfovibrio desulfuricans.the possibility that sulfate-reducing microorganisms contribute to u(vi) reduction in sedimentary environments was investigated. u(vi) was reduced to u(iv) when washed cells of sulfate-grown desulfovibrio desulfuricans were suspended in a bicarbonate buffer with lactate or h2 as the electron donor. there was no u(vi) reduction in the absence of an electron donor or when the cells were killed by heat prior to the incubation. the rates of u(vi) reduction were comparable to those in respiratory fe( ...19921575486
refinement of rubredoxin from desulfovibrio vulgaris at 1.0 a with and without restraints.x-ray data have been recorded from crystals of rubredoxin derived from the bacterium desulfovibrio vulgaris to a resolution of 1.0 a using in part synchrotron radiation and in part x-rays from a sealed-tube mo k alpha source. in both cases an imaging-plate scanner was used as detector. the space group of the crystals is p2(1) with cell dimensions a = 19.97, b = 41.45, c = 24.41 a and beta = 108.3 degrees. the overall merging r(i) factor between symmetry-related reflections was 5.8%. the model wa ...19921616692
the primary structures of the flavodoxins from two strains of desulfovibrio gigas. cloning and nucleotide sequence of the structural genes.the structural genes coding for the flavodoxin proteins from two different strains of the sulfate-reducing bacteria desulfovibrio gigas (atcc 19364/ncib 9332 and atcc 29494/dsm 496) have been identified, cloned and the nucleotide sequence established. the protein sequences derived from the gene from each strain share a sequence identity of 66% with regions directly involved in binding the flavin mononucleotide cofactor being the most homologous. both aromatic residues that flank the flavin isoal ...19921627649
effects of phosphate on the binding of fmn and riboflavin by apoflavodoxin from desulfovibrio vulgaris (hildenborough). 19921634005
structure determination of a novel cyclic phosphocompound isolated from desulfovibrio desulfuricans.the structure of a novel diphosphodiester compound recently detected in desulfovibrio desulfuricans cells [santos, fareleira, pedregal, legall & xavier (1991) eur. j. biochem. 201, 283-287] was fully elucidated using a combination of n.m.r. techniques in aqueous and in methanolic solutions. the novel metabolite was identified as 3-methyl-1,2,3,4-tetrahydroxybutane-1,3-cyclic bisphosphate, and the minimum energy conformation is presented. the two chiral centres have the relative configuration rs.19921637331
sequence variability in bacterial cytochromes c.cytochromes c are proteins that can be defined both phenotypically and by their possession of a characteristic sequence motif. many sequences from bacterial sources are known, and new ones are being reported every year. an analysis can be made as to what fraction of new sequences are members of already known classes or subclasses, and how many map into previously uninhabited regions of sequence space.19911646017
structural and functional approach toward a classification of the complex cytochrome c system found in sulfate-reducing bacteria.following the discovery of the tetraheme cytochrome c3 in the strict anaerobic sulfate-reducing bacteria (postgate, j.r. (1954) biochem. j. 59, xi; ishimoto et al. (1954) bull. chem. soc. japan 27, 564-565), a variety of c-type cytochromes (and others) have been reported, indicating that the array of heme proteins in these bacteria is complex. we are proposing here a tentative classification of sulfate- (and sulfur-) reducing bacteria cytochromes c based on: number of hemes per monomer, heme axi ...19911646022
cooperative ligand reorientations in cytochrome c3: a molecular dynamics simulation.molecular dynamics simulations of a tetraheme cytochrome c3 were performed to investigate dynamic aspects of the motion of the axial heme iron ligands. it was found that persistent transitions between alternate axial imidazole orientations of the histidine incorporated in the cxxch heme binding sequence occurred via correlated motions. the correlated motions involved virtually all of the atoms comprising the polypeptide backbone of the heme binding sequence as well as the histidine imidazole sid ...19911646028
identification of the site of interaction between cytochrome c3 and ferredoxin using peptide mapping of the cross-linked complex.structural studies carried out on a cross-linked complex between cytochrome c3 and ferredoxin i, both isolated from desulfovibrio desulfuricans norway, allowed the identification of the site of interaction between the two redox proteins. staphylococcus aureus proteinase and chymotrypsin digestions led to characterization of peptides containing both cytochrome c3 and ferredoxin sequences. the cytochrome c3 sequences involved in the three isolated cross-linked peptides contained several lysine res ...19911646631
full assignment of heme redox potentials of cytochrome c3 of d. vulgaris miyazaki f by heme assignment of the 1h-nmr spectrum of cytochrome c3 of d. vulgaris miyazaki f, a tetraheme protein, was established. the major reduction of the heme turned out to take place in the order of hemes i, iii, iv and ii (numbering in the crystal structure). the hemes with the smallest and greatest solvent accessibility were reduced at the highest and lowest potentials on average, respectively. a cooperative interheme interaction was attributed to a pair of the closest hemes, namely, ...19911648512
interactions of heavy metals with organisms and proteins.voltammetric techniques [differential pulse polarography (dpp) and differential pulse anodic stripping voltammetry (dpasv)] have been used to determine, at various ph, conditional differential functions and average equilibrium constants of copper, zinc and lead with the bacteria klebsiella pneumoniae and methanosarcine, the alga selenastrum capricornutum printz and the proteins horse-heart cytochrome c and the soluble extract of sulphate-reducing bacteria. the buffer intensity in terms of metal ...19911652791
kinetic studies of the electron exchange reaction between the octaheme cytochrome c3 (mr 26000) and the hydrogenase from desulfovibrio desulfuricans norway.the octaheme cytochrome c3 (mr 26000) from desulfovibrio desulfuricans norway was studied using cyclic voltammetry at the pyrolytic graphite electrode. the kinetics of reduction of the octaheme cytochrome c3 (mr 26000) from d. desulfuricans norway by the ni-fe-se hydrogenase purified from the same organism was investigated by an electrochemical method. from cyclic voltammetry experiments a value of 8.108m-1s-1 was obtained for the second order homogenous rate constant of the electron transfer be ...19911652960
expression of the gene encoding cytochrome c3 from the sulfate-reducing bacterium desulfovibrio vulgaris in the purple photosynthetic bacterium rhodobacter sphaeroides.the gene encoding cytochrome c3 (cyc-gene) from desulfovibrio vulgaris (hildenborough) was cloned by g. voordouw and s. brenner (1986, eur. j. biochem. 159, 347-351). the gene was expressed in escherichia coli but only the apoprotein was observed (w. pollock, p. chemerika, m. forrest, j. beatty, and g. voordouw, 1989, j. gen. microbiol. 135, 2319-2328). in this study, the cyc-gene was cloned into the broad host range vector prk404 and then introduced into the purple photosynthetic bacterium rhod ...19911654796
partial sequences of high-molecular-weight cytochrome c isolated from desulfovibrio vulgaris miyazaki.a polyhemic high-molecular-weight cytochrome c (hmc) of mr 67,000 was purified from desulfovibrio vulgaris miyazaki. this cytochrome is composed of a single peptide chain. unlike other c-type cytochromes, hmc deteriorates slowly in atmospheric oxygen. two peptide fragments of mr 33,100 (l peptide) and mr 19,100 (s peptide) were isolated and their n-terminal sequences determined to be plpgatgeqradlveigvmakftnlelpkv (l peptide) and gtlpavaipefvtigvlk (s peptide). the established sequence of the l ...19911656429
ferredoxin electron transfer site on cytochrome c3. structural hypothesis of an intramolecular electron transfer pathway within a tetra-heme specify electron exchanges involving desulfovibrio desulfuricans norway tetra-heme cytochrome c3, the chemical modification of arginine 73 residue, was performed. biochemical and biophysical studies have shown that the modified cytochrome retains its ability to both interact and act as an electron carrier with its redox partners, ferredoxin and hydrogenase. moreover, the chemical modification effects on the cytochrome c3 1h nmr spectrum were similar to that induced by the presence of ferredox ...19911657066
the primary structure of rubrerythrin, a protein with inorganic pyrophosphatase activity from desulfovibrio vulgaris. comparison with hemerythrin and rubredoxin.the complete polypeptide chain of rubrerythrin from the sulfate reducing bacterium desulfovibrio vulgaris, strain hildenborough ncib 8303, was found by protein chemical techniques to consist of 191 residues and to have the amino acid sequence [sequence: see text] the c-terminal part of the protein (position 153----191) shows the typical sequence features of rubredoxin, a protein with a nonheme iron center also present in the same and other desulfovibrio species. based on the known three-dimensio ...19911657933
molecular dynamics simulations of the cytochrome c3-rubredoxin complex from desulfovibrio vulgaris.molecular dynamics simulations have been carried out on the complex formed between the tetraheme cytochrome c3 and the iron protein rubredoxin from the sulfate-reducing bacterium desulfovibrio vulgaris. these simulations were performed both with explicit solvent water molecules included, and without solvent molecules using a distance-dependent dielectric constant to approximate the screening effects of solvent. the results of both simulations are strikingly different, indicating that the represe ...19911658779
spectroscopic studies on aps reductase isolated from the hyperthermophilic sulfate-reducing archaebacterium archaeglobus fulgidus.adenylyl sulfate (aps) reductase, the key enzyme of the dissimilatory sulfate respiration, catalyzes the reduction of aps (the activated form of sulfate) to sulfite with release of amp. a spectroscopic study was carried out with the aps reductase purified from the extremely thermophilic sulfate-reducing archaebacterium archaeoglobus fulgidus dsm 4304. combined ultraviolet/visible spectroscopy and low temperature electron paramagnetic resonance (epr) studies were used in order to characterize the ...19911659811
simulation of the electrochemical behavior of multi-redox systems. current potential studies on multiheme cytochromes.the direct unmediated electrochemical response of the tetrahemic cytochrome c3 isolated from sulfate reducers desulfovibrio baculatus (dsm 1743) and d. vulgaris (strain hildenborough), was evaluated using different electrode systems [graphite (edge cut), gold, semiconductor (ino2) and mercury)] and different electrochemical methods (cyclic voltammetry and differential pulse voltammetry). a computer program was developed for the theoretical simulation of a complete cyclic voltammetry curve, based ...19911662131
information from e.p.r. spectroscopy on the iron-sulphur centres of the iron-molybdenum protein (aldehyde oxidoreductase) of desulfovibrio gigas.e.p.r. spectra of reduced iron-sulphur centres of the aldehyde oxidoreductase (iron-molybdenum protein) of desulfovibrio gigas were recorded at x-band and q-band frequencies and simulated. results are consistent with the view that only two types of [2fe-2s] clusters are present, as in eukaryotic molybdenum-containing hydroxylases. the data indicate the fe/si centre to be very similar, and the fe/sii centre somewhat similar, to these centres in the eukaryotic enzymes.19911662489
a thermodynamic model for the cooperative functional properties of the tetraheme cytochrome c3 from desulfovibrio gigas.a thermodynamic model is presented to describe the redox behaviour of the tetraheme cytochrome c3 from desulfovibrio gigas. this molecule displays different intrinsic redox potentials for the four hemes and during the redox titration process, interactions among different hemes occur, thus altering the values of redox potentials according to which of the hemes are oxidized [santos, h., moura, j.j.g., moura, i., legall, j. & xavier, a.v. (1984) eur. j. biochem. 141, 283-296]. this complex cooperat ...19911662600
kinetic study of the reduction mechanism for desulfovibrio gigas cytochrome c3.the kinetic aspects of the reduction process in cytochrome c3 from desulfovibrio gigas have been investigated over a wide range of ph values ranging between ph 5.8 and ph 9.8. the data have been analyzed in the framework of an i2h4 interaction network coupled to a proton-linked equilibrium between two tertiary structures (cornish-bowden, a. & koshland, d.e. jr (1970) j. biol. chem. 245, 6241-6250). the kinetic rate constants for the reduction of the four hemes for the two tertiary conformations ...19911662601
effects of amino acid substitution on three-dimensional structure: an x-ray analysis of cytochrome c3 from desulfovibrio vulgaris hildenborough at 2 a resolution.the three-dimensional structure of cytochrome c3 from desulfovibrio vulgaris hildenborough has been determined by use of the molecular replacement method and refined at 2.0 a resolution. a suitable crystal of the cytochrome c3 was obtained from buffer solution (25 mm tris-hcl, ph 7.4), with 75% ethanol as the precipitating reagent. crystallographic data are as follows: a = 43.17 a, b = 62.91 a, c = 41.17 a, orthorhombic, p2(1)2(1)2(1) and z = 4. constrained least-squares refinement and a molecul ...19911663945
spectroscopic studies of cobalt and nickel substituted rubredoxin and desulforedoxin.the single iron site of rubredoxin was replaced by nickel and cobalt. the near-infrared/visible/uv spectra of these metal derivatives show ligand-field transitions and charge-transfer bands which closely resemble those of simple tetrathiolate complexes, indicating a tetrahedral arrangement of the sulfur cysteinyl ligands around the metal core. the 1h nmr spectra of the nickel and cobalt derivatives reveal extremely low-field contact shifted resonances of one proton intensity assigned to beta-ch2 ...19911664851
1h nmr studies on ferricytochrome c3 from desulfovibrio vulgaris miyazaki f and its interaction with ferredoxin i.the 1h nmr signals of the heme methyl, propionate and related chemical groups of cytochrome c3 from desulfovibrio vulgaris miyazaki f (d.v. mf) were site-specifically assigned by means of 1d noe, 2d dqfcosy and 2d tocsy spectra. they were consistent with the site-specific assignments of the hemes with the highest and second-lowest redox potentials reported by fan et al. (biochemistry, 29 (1990) 2257-2263). the site-specific heme assignments were also supported by noe between the methyl groups of ...19911668723
induction and partial purification of bacteriophages from desulfovibrio vulgaris (hildenborough) and desulfovibrio desulfuricans atcc 13541.bacteriophages were induced from cultures of desulfovibrio vulgaris ncimb 8303 and desulfovibrio desulfuricans atcc 13541 by uv light. the optimum time of uv exposure was 1 min and the maximum yield of phage was obtained 9-10 h after uv treatment. the two phage preparations were compared by restriction enzyme analysis and southern blot hybridization. the nucleic acid from both phages was cut by restriction endonucleases specific for double-stranded dna. the phage dnas from d. vulgaris and d. des ...19911683398
localization of membrane-associated (nife) and (nifese) hydrogenases of desulfovibrio vulgaris using immunoelectron microscopic procedures.the intracellular location of membrane-associated (nife) and (nifese) hydrogenases of desulfovibrio vulgaris was determined using pre-embedding and post-embedding immunoelectron microscopic procedures. polyclonal antisera directed against the purified (nife) and (nifese) hydrogenases were raised in rabbits. one-day-old cultures of d. vulgaris, grown on a lactate/sulfate medium, were used for all experiments in these studies. for post-embedding labeling studies cells were fixed with 0.2% glutaral ...19901696542
reduction of the amount of periplasmic hydrogenase in desulfovibrio vulgaris (hildenborough) with antisense rna: direct evidence for an important role of this hydrogenase in lactate establish the function of the periplasmic fe-only hydrogenase in the anaerobic sulfate reducer desulfovibrio vulgaris (hildenborough), derivatives with a reduced content of this enzyme were constructed by introduction of a plasmid that directs the synthesis of antisense rna complementary to hydrogenase mrna. it was demonstrated that the antisense rna technique allowed specific suppression of the synthesis of this hydrogenase in d. vulgaris by decreasing the amount of hydrogenase mrna but did ...19911711025
phylogenetic analysis and evolution of rnase p rna in proteobacteria.the secondary structures of the eubacterial rnase p rnas are being elucidated by a phylogenetic comparative approach. sequences of genes encoding rnase p rna from each of the recognized subgroups (alpha, beta, gamma, and delta) of the proteobacteria have now been determined. these sequences allow the refinement, to nearly the base pair level, of the phylogenetic model for rnase p rna secondary structure. evolutionary change among the rnase p rnas was found to occur primarily in four discrete str ...19911711030
structure and evolution of ribonuclease p rna.eubacterial rnase p contains a catalytic rna that cleaves 5' leader sequences from precursor trnas. we review the current understanding of rnase p rna structure and evolution, from the perspective of phylogenetic comparative analysis.19911722425
redox and flavin-binding properties of recombinant flavodoxin from desulfovibrio vulgaris (hildenborough).flavodoxin from desulfovibrio vulgaris (hildenborough) has been expressed at a high level (3-4% soluble protein) in escherichia coli by subcloning a minimal insert carrying the gene behind the tac promoter of plasmid pdk6. the recombinant protein was readily isolated and its properties were shown to be identical to those of the wild-type protein obtained directly from d. vulgaris, with the exception that the recombinant protein lacks the n-terminal methionine residue. detailed measurements of th ...19911765070
iron-sulphur clusters in electron transfer, catalysis and control. 19911783185
characterization of metabolic performance of methanogenic granules treating brewery wastewater: role of sulfate-reducing bacteria.granules from an upflow anaerobic sludge blanket system treating a brewery wastewater that contained mainly ethanol, propionate, and acetate as carbon sources and sulfate (0.6 to 1.0 mm) were characterized for their physical and chemical properties, metabolic performance on various substrates, and microbial composition. transmission electron microscopic examination showed that at least three types of microcolonies existed inside the granules. one type consisted of methanothrix-like rods with low ...19911785921
cloning, sequencing, and expression of the gene encoding the high-molecular-weight cytochrome c from desulfovibrio vulgaris using a synthetic deoxyoligonucleotide probe designed to recognize the structural gene for cytochrome cc3 from desulfovibrio vulgaris hildenborough, a 3.7-kb xhoi genomic dna fragment containing the cc3 gene was isolated. the gene encodes a precursor polypeptide of 58.9 kda, with an nh2-terminal signal sequence of 31 residues. the mature polypeptide (55.7 kda) has 16 heme binding sites of the form c-x-x-c-h. covalent binding of heme to these 16 sites gives a holoprotein of 65.5 kda with prope ...19911846136
s = 9/2 epr signals are evidence against coupling between the siroheme and the fe/s cluster prosthetic groups in desulfovibrio vulgaris (hildenborough) dissimilatory sulfite reductase.sulfite reductases contain siroheme and iron-sulfur cluster prosthetic groups. the two groups are believed to be structurally linked via a single, common ligand. this chemical model is based on a magnetic model for the oxidized enzyme in which all participating iron ions are exchange coupled. this description leads to two serious discrepancies. although the iron-sulfur cluster is assumed to be a diamagnetic cubane, [4fe-4s]2+, all iron appears to be paramagnetic in mössbauer spectroscopy. on the ...19911847685
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