characterization of an operon encoding an nadp-reducing hydrogenase in desulfovibrio fructosovorans.a genomic dna fragment from desulfovibrio fructosovorans, which strongly hybridized with the hydab genes from desulfovibrio vulgaris hildenborough, was cloned and sequenced. this fragment was found to contain four genes, named hnda, hndb, hndc, and hndd. analysis of the sequence homologies indicated that hnda shows 29, 21, and 26% identity with the 24-kda subunit from bos taurus complex i, the 25-kda subunit from paracoccus denitrificans nadh dehydrogenase type i, and the n-terminal domain of ho ...19957751270
1h nuclear-magnetic-resonance investigation of oxidized fe4s4 ferredoxin from thermotoga maritima. hyperfine-shifted resonances, sequence-specific assignments and secondary structure.the oxidized fe4s4 ferredoxin from the hyperthermophilic bacterium thermotoga maritima has been investigated by one- and two-dimensional nmr in order to characterize its hyperfine-shifted resonances originating from the cysteinyl cluster ligands and to assign its resonances in the diamagnetic shift range. the chemical shift and relaxation time pattern of the hyperfine-shifted signals is very similar to other oxidized fe4s4 ferredoxins. a tentative sequence-specific assignment of these resonances ...19957758460
effect of water-miscible organic solvents on the catalytic activity of cytochrome c.the effect of five water-miscible organic solvents (tetrahydrofuran, n,n-dimethylformamide, acetonitrile, 2-propanol, and methanol) on the oxidation of pinacyanol chloride (quinaldine blue) by horse heart cytochrome c was determined. hydrogen peroxide was used as the oxidant, and a change in catalytic property of the dissolved protein was observed after a certain threshold concentration of the organic solvent had been reached. the maximum specific activity was correlated with the dimroth-reichar ...19937764253
microbial reduction of sulfur dioxide with anaerobically digested municipal sewage biosolids as electron donors.a concentrated stream of sulfur dioxide (so2) is produced by regeneration of the sorbent in certain new regenerable processes for the desulfurization of flue gas. we have previously proposed that this so2 can be converted to elemental sulfur for disposal or byproduct recovery using a microbial/claus process. in this process, two-thirds of the so2-reducing gas stream would be contacted with a mixed culture containing sulfate-reducing bacteria (srb), where so2 would act as an electron acceptor wit ...19957766099
epr and redox characterization of ferredoxins i and ii from desulfovibrio vulgaris miyazaki.detailed redox titrations monitored by epr and uv-visible spectroscopies have been carried out on the dimeric ferredoxins i and ii from desulfovibrio vulgaris miyazaki. ferredoxin ii contains a unique [4fe-4s] cluster per subunit characterized by a midpoint potential of -417 mv at 24 degrees c. the enthalpic and entropic contributions to the redox free energy variation of this cluster have been determined from the temperature dependence of the midpoint potential and compared to the data reported ...19957779085
molecular cloning of the isoquinoline 1-oxidoreductase genes from pseudomonas diminuta 7, structural analysis of iora and iorb, and sequence comparisons with other molybdenum-containing hydroxylases.the iora and iorb genes from the isoquinoline-degrading bacterium pseudomonas diminuta 7, encoding the heterodimeric molybdo-iron-sulfur-protein isoquinoline 1-oxidoreductase, were cloned and sequenced. the deduced amino acid sequences iora and iorb showed homologies (i) to the small (gamma) and large (alpha) subunits of complex molybdenum-containing hydroxylases (alpha beta gamma/alpha 2 beta 2 gamma 2) possessing a pterin molybdenum cofactor with a monooxo-monosulfido-type molybdenum center, ( ...19957782304
a gene encoding a cytochrome c oxidase-like protein is located closely to the cytochrome c-553 gene in the anaerobic bacterium, desulfovibrio vulgaris (miyazaki f).the gene encoding cytochrome c-553 from desulfovibrio vulgaris (miyazaki f) was cloned using a synthetic oligodeoxyribonucleotide probe. the nucleotide sequence indicated that cytochrome c-553 was synthesized as a precursor protein with an nh2-terminal signal sequence of 23 residues. in the cloned dna fragment, there are three other open reading frames whose products have 191, 157, 541 amino acid residues, respectively. the putative orf-4 product is highly homologous with the cytochrome c oxidas ...19957783682
genetic diversity of desulfovibrio spp. in environmental samples analyzed by denaturing gradient gel electrophoresis of [nife] hydrogenase gene fragments.the genetic diversity of desulfovibrio species in environmental samples was determined by denaturing gradient gel electrophoresis (dgge) of pcr-amplified [nife] hydrogenase gene fragments. five different pcr primers were designed after comparative analysis of [nife] hydrogenase gene sequences from three desulfovibrio species. these primers were tested in different combinations on the genomic dnas of a variety of hydrogenase-containing and hydrogenase-lacking bacteria. one primer pair was found t ...19957793940
structural changes caused by site-directed mutagenesis of tyrosine-98 in desulfovibrio vulgaris flavodoxin delineated by 1h and 15n nmr spectroscopy: implications for redox potential modulation.flavodoxins mediate electron transfer at low redox potential between the prosthetic groups of other proteins. interactions between the protein and the flavin mononucleotide cofactor shift both the oxidized/semiquinone and semiquinone/hydroquinone redox potentials significantly from their free-in-solution values. in order to investigate the possible role that the tyrosine at position 98 plays in this process, we have used heteronuclear three-dimensional nmr spectroscopy to determine the solution ...19947803393
crystal structure of the ferredoxin i from desulfovibrio africanus at 2.3 a resolution.the crystal structure of the ferredoxin i from the sulfate-reducing bacterium desulfovibrio africanus (dafdi) has been solved and refined by x-ray diffraction. the crystals are orthorhombic with a = 96.6 a, b = 58.1 a, and c = 20.7 a, space group p2(1)2(1)2, and two ferredoxin molecules per asymmetric unit. the initial electron density map has been obtained by combining phasing by molecular replacement methods, anomalous scattering, and noncrystallographic averaging. the final crystallographic r ...19947803404
characterization of the diversity of sulfate-reducing bacteria in soil and mining waste water environments by nucleic acid hybridization techniques.nucleic acid hybridization techniques were used to characterize the sulfate-reducing bacterial communities at seven waste water and two soil sites in canada. genomic dna was obtained from liquid enrichment cultures of samples taken from these nine sites. the liquid enrichment protocol favored growth of the sulfate-reducing bacterial component of the communities at these sites. the genomic dna preparations were analyzed with (i) a specific gene probe aimed at a single genus (desulfovibrio), (ii) ...19947804906
carbon-13 nmr studies of the influence of axial ligand orientation on haem electronic structure.three-quarters of the carbon-13 resonances of nuclei attached to the four haems of desulfovibrio vulgaris ferricytochrome c3 are assigned. preliminary analysis of their fermi contact interactions shows that the shifts are directly related to the orientation of both of the axial histidine ligands in each case and the approach can therefore be used to obtain structural information in other cytochromes with bis-histidinyl coordination. the implications for the control of redox potential in cytochro ...19957811726
1h nmr investigation of the paramagnetic cluster environment in pyrococcus furiosus three-iron ferredoxin: sequence-specific assignment of ligated cysteines independent of tertiary and two-dimensional 1h nmr data tailored to detect paramagnetically relaxed protons near the s = 1/2, three-iron-sulfur cluster of the ferredoxin from the hyperthermophile pyrococcus furiosus are analyzed to sequence specifically assign the hyperfine shifted ligated cysteine signals, to determine the nature of the secondary structural elements on which these cysteines reside, and to define the tertiary contacts of the cluster with the remainder of the previously characterized secondary stru ...19957819255
monoheme cytochromes. 19947830605
tetraheme cytochromes. 19947830606
cytochrome c3 (m(r) 26,000) isolated from sulfate-reducing bacteria and its relationships to other polyhemic cytochromes from desulfovibrio. 19947830607
hexadecaheme cytochrome c. 19947830608
ferredoxins. 19947830609
flavodoxins. 19947830610
rubredoxin in crystalline state. 19947830611
characterization of three proteins containing multiple iron sites: rubrerythrin, desulfoferrodoxin, and a protein containing a six-iron cluster. 19947830612
aldehyde oxidoreductases and other molybdenum containing enzymes. 19947830613
aldehyde oxidoreductases and other molybdenum-containing enzymes. 19947830614
desulforubidin: dissimilatory, high-spin sulfite reductase of desulfomicrobium species. 19947830615
desulfofuscidin: dissimilatory, high-spin sulfite reductase of thermophilic, sulfate-reducing bacteria. 19947830616
nickel-iron-selenium hydrogenase. 19947830621
structure and dynamics of ferrocytochrome c553 from desulfovibrio vulgaris studied by nmr spectroscopy and restrained molecular dynamics.the solution structure of desulfovibrio vulgaris hildenborough (dvh) ferrocytochrome c553 has been determined by nuclear magnetic resonance spectroscopy and combined simulated annealing/high temperature restrained molecular dynamics calculations. this three-stage protocol consists of an initial determination of overall fold from randomised co-ordinates, followed by a 20 picosecond exploratory stage, during which the non-bonded terms are simplified to facilitate as broad a sampling of conformatio ...19957844834
redox enzymes. splitting molecular hydrogen. 19957854404
crystal structure of the nickel-iron hydrogenase from desulfovibrio gigas.the x-ray structure of the heterodimeric ni-fe hydrogenase from desulfovibrio gigas, the enzyme responsible for the metabolism of molecular hydrogen, has been solved at 2.85 a resolution. the active site, which appears to contain, besides nickel, a second metal ion, is buried in the 60k subunit. the 28k subunit, which coordinates one [3fe-4s] and two [4fe-4s] clusters, contains an amino-terminal domain with similarities to the redox protein flavodoxin. the structure suggests plausible electron a ...19957854413
electrostatic effects of surface acidic amino acid residues on the oxidation-reduction potentials of the flavodoxin from desulfovibrio vulgaris (hildenborough).the flavodoxin from desulfovibrio vulgaris (hildenborough) is a member of a family of small, acidic proteins that contain a single noncovalently bound flavin mononucleotide (fmn) cofactor. these proteins function as low-potential one-electron transferases in bacteria. a distinguishing feature of these flavoproteins is the dramatic decrease in the midpoint potential of the semiquinone/hydroquinone couple of the fmn upon binding to the apoprotein (-172 mv for fmn free in solution versus -443 mv wh ...19957880813
recombinant desulfovibrio vulgaris rubrerythrin. isolation and characterization of the diiron domain.the gene encoding desulfovibrio (d.) vulgaris rubrerythrin (prickril, b. c., kurtz, d. m., jr., legall, j., & voordouw, g. (1991) biochemistry 30, 1118), a protein of unknown function containing both fes4 and (mu-oxo)diiron sites, was cloned and overexpressed in escherichia coli. upon cell lysis, the overexpressed protein was found in an insoluble form deficient in iron. iron was incorporated in vitro by dissolving the protein in 3 m guanidinium chloride, adding fe(ii) anaerobically and diluting ...19957880826
involvement of electrostatic interactions in cytochrome c complex formations.structural studies on various electron transfer complexes involving the tetrahemic cytochrome c3 provided evidence that one of the hemes (heme 4) is the interacting site on the molecule. the reactivity of this particular heme is allocated to the positive charges found around the heme group which are strongly involved in the electrostatic interaction processes. electrostatic and hydrophobic effects in complex formation are considered on the basis of two electron transfer complex examples: the sol ...19947880890
individual redox characteristics and kinetic properties of the hemes in cytochromes c3: new methods of investigation.the elucidation of the role of the four hemes in cytochromes c3 requires several complementary approaches. the measurements and the assignment of the redox potentials resort to magnetic spectroscopies, epr and nmr, which are able to discriminate the hemes. the origin of the differences between the redox properties of the hemes can be studied by comparing their thermodynamic parameters delta s and delta h, as measured by the temperature dependence of their individual potentials. lastly, the avail ...19947880891
a detailed comparison of the refined structures of cytochrome c3 molecules from two strains in desulfovibrio vulgaris: the relationship between the heme structures and their redox properties.the refined structures of the cytochrome c3 molecules from desulfovibrio vulgaris miyazaki and hildenborough have been compared in detail. though there are no significant differences of the overall structure and spatial arrangement of four heme groups between two molecules, there are some unique features with regard to the local structures near the heme pockets. two of the heme groups show significant differences including a hydrogen bonding scheme between the imidazole rings and water molecules ...19947880892
molecular and structural basis of electron transfer in tetra- and octa-heme cytochromes.the first three-dimensional structure of a dimeric, octa-heme cytochrome c3 (m(r) 26000) from desulfovibrio desulfuricans norway, established at 2.2 a resolution, is briefly presented and compared to the known 3-d-structures of different c3-type tetraheme cytochromes, in order to contribute to a better understanding of the function of multiheme clusters and of the role of conserved amino acids implicated in possible electron transfer pathways. the dimeric protein crystallizes in the space group ...19947880893
molecular biology of c-type cytochromes from desulfovibrio vulgaris hildenborough.sulfate reducing bacteria of the genus desulfovibrio harbor a wide variety of redox proteins. three different c-type cytochromes, cytochrome c-553, cytochrome c3 and the high molecular mass cytochrome have been isolated from these bacteria. the high molecular mass cytochrome is part of an operon that encodes a transmembrane protein complex that mediates electron transfer across the cytoplasmic membrane. the physiological function of the other two cytochromes is less clear. they are encoded by mo ...19947880894
recent advances in the characterization of the hexadecahemic cytochrome c from desulfovibrio.the biochemical characterization of the high molecular mass cytochromes c (hmc) isolated from desulfovibrio vulgaris has led to some controversy as regards their molecular size and subunit structure as well as their heme content and redox properties. recently developed genetic techniques have made it possible to reach some definite conclusions about the structural and functional properties of the cytochrome. the hexadecahemic hmc comprises four domains which resemble the tetrahemic cytochrome c3 ...19947880895
(h)ncaha and (h)cannh experiments for the determination of the vicinal coupling constants related to the phi-torsion angle.a set of three-dimensional triple-resonance experiments is described which provide 3j(hnhalpha), 3j(hnco), 3j(hncbeta) and 3j(halphaco) coupling constants. the pulse sequences generate e.cosy-like multiplet patterns and comprise a magnetization transfer from the amide proton to the alpha-proton or vice versa via the directly bound heteronuclei. for residues with the 1h(alph) spin resonating close to the h2o signal, a modified hnca experiment can be employed to measure the vicinal 1h(n),1h(alpha) ...19957881271
conservation of the genes for dissimilatory sulfite reductase from desulfovibrio vulgaris and archaeoglobus fulgidus allows their detection by pcr.the structural genes for dissimilatory sulfite reductase (desulfoviridin) from desulfovibrio vulgaris hilden-borough were cloned as a 7.2-kbp sacii dna fragment. nucleotide sequencing indicated the presence of a third gene, encoding a protein of only 78 amino acids, immediately downstream from the genes for the alpha and beta subunits (dsva and dsvb). we designated this protein dsvd and the gene encoding it the dsvd gene. the alpha- and beta-subunit sequences are highly homologous to those of th ...19957887608
localization and specificity of cytochromes and other electron transfer proteins from sulfate-reducing bacteria.recently data have accumulated concerning the electron transfer chains of sulfate-reducing bacteria in general and of the genus desulfovibrio in particular. because of the ever growing number of newly discovered individual redox proteins, it has become essential to try to assign them to physiologically relevant chains. this work presents some new data concerning the localization of these proteins within the bacterial cell and the specificity of electron transfer between the three types of hydrog ...19947893817
axial coordination and reduction potentials of the sixteen hemes in high-molecular-mass cytochrome c from desulfovibrio vulgaris (hildenborough).a spectroelectrochemical study is described of the sixteen hemes in the high-molecular-mass, monomeric cytochrome c (hmc) from the periplasmic space of desulfovibrio vulgaris, strain hildenborough. one of the hemes has special properties. in the oxidized state at ph 7 it is predominantly high-spin, s = 5/2, with a g perpendicular value of less than 6 indicative of quantum-mechanical mixing with a low-lying (800 cm-1) s = 3/2 state; the balance is probably a low-spin derivative. the high-spin hem ...19947925451
community structure of a microbial mat: the phylogenetic dimension.traditional studies of microbial communities are incomplete because of the inability to identify and quantify all contributing populations. in the present study, we directly determine the abundance and distribution of sulfate-reducing bacterial populations in a microbial mat community by using hybridization probes complementary to the 16s-like rrnas of major phylogenetic groups. most of the major groups were found in this single community, distributed for the most part in nonoverlapping depth in ...19947937858
analysis of oxidative titrations of desulfovibrio gigas hydrogenase; implications for the catalytic mechanism.the oxidative titrations of hydrogenase (hase) from desulfovibrio gigas [barondeau, d. p., roberts, l. m., & lindahl, p. a. (1994) j. am. chem. soc. 116, 3442] were simulated using model descriptions of the redox reactions in the enzyme. the data fit best to a model that assumed hase contains one [fe3s4]1+/0 cluster, two [fe4s4]2+/1+ clusters, and a ni center stable in four redox states (ni-b, ni-si, ni-c, and ni-r), each separated by one electron. a model in which ni-si, ni-c, and ni-r correspo ...19947947844
mcd and 1h-nmr spectroscopic studies of desulfovibrio africanus ferredoxin i: revised amino-acid sequence and identification of secondary structure.desulfovibrio africanus ferredoxin i was studied by magnetic circular dichroism and 1h-nmr spectroscopies. these showed the presence of histidine and tryptophan, in contrast to the previously reported amino-acid sequence (bruschi and hatchikian (1982) biochimie 64, 503-507). this was redetermined and the revised sequence shown to contain both histidine and tryptophan, as well as four other corrections (sery et al. (1994) biochemistry, submitted). electrospray mass spectrometry confirmed the mass ...19947947979
crystal structure of cytochrome c3 from desulfovibrio desulfuricans norway at 1.7 a resolution.the crystal structure of cytochrome c3 (m(r) 13,000) from desulfovibrio desulfuricans (118 residues, four heme groups) has been crystallographically refined to 1.7 a resolution using a simulated annealing method, based on the structure-model at 2.5 a resolution, already published. the final r-factor for 10,549 reflections was 0.198 covering the range from 5.5 to 1.7 a resolution. the individual temperature factors were refined for a total of 1059 protein atoms, together with 126 bound solvent mo ...19947966289
two-dimensional nmr studies of the flavin binding site of desulfovibrio vulgaris flavodoxin in its three redox states.the riboflavin 5'-monophosphate (fmn) binding site of desulfovibrio vulgaris flavodoxin in the diamagnetic oxidized and two-electron reduced form was investigated using two-dimensional proton nmr. the nmr results are compared to existing x-ray crystallographic data. in the paramagnetic one-electron reduced redox state resonances of protons which are close to the fmn ring are strongly broadened due to the paramagnetic properties of the flavin ring. from comparison of the nmr spectra of the three ...19947979368
comparative analysis of the 16s rrna gene sequence of the putative agent of proliferative ileitis of hamsters.proliferative ileitis of hamsters is consistently associated with the presence of intracellular bacteria in affected ileal epithelial cells. the 16s rrna gene sequence of the putative etiologic agent of proliferative ileitis was determined by using cell culture-maintained organisms. the highest level of relatedness (98.4%) was observed with a newly described obligately intracellular bacterium obtained from porcine intestines, and the level of homology with desulfovibrio desulfuricans was 87.5%.19947981108
electronic properties of the dissimilatory sulphite reductase from desulfovibrio vulgaris (hildenborough): comparative studies of optical spectra and relative reduction potentials for the [fe4s4]-sirohaem prosthetic centres.the dissimilatory sulphite reductase (desulfoviridin) from the sulphate-reducing bacterium desulfovibrio vulgaris (hildenborough) displays distinct optical and redox characteristics relative to the haem subunit of escherichia coli assimilatory sulphite reductase. for high-spin pentaco-ordinate desulfoviridin there is minimal change in the absorbance of the oxidized chromophores both after reduction or after addition of exogenous ligands. a ligand-metal charge-transfer band approximately 702 nm i ...19947998978
effects of the tyr64 substitution on the stability of cytochrome c553, a low oxidoreduction-potential cytochrome from desulfovibrio vulgaris hildenborough.cytochrome c553 from sulfate-reducing bacteria is a low-oxidoreduction-potential cytochrome. the primary and tertiary structures show notable differences when compared to mitochondrial cytochromes. tyr64 replacement in cytochrome c553 provides evidence that this residue is not directly involved in the potential modulation but is mostly implicated in the hydrogen-bond network around the heme. while the different variants obtained did not induce drastic structural modifications, they did affect th ...19948001560
a blue non-heme iron protein from desulfovibrio gigas.a novel iron-containing blue protein, named neelaredoxin, was isolated from the sulfate-reducing bacterium desulfovibrio gigas. it is a monomeric protein with a molecular mass of 15 kda containing two iron atoms/molecule. the n-terminal sequence of neelaredoxin has similarity to the second domain of desulfoferrodoxin, a protein purified from desulfovibrio vulgaris hildenborough. this finding supports the hypothesis that the gene coding for desulfoferrodoxin (rbo) might have arisen from a gene fu ...19948001576
overproduction of the prismane protein from desulfovibrio desulfuricans atcc 27774 in desulfovibrio vulgaris (hildenborough) and epr spectroscopy of the [6fe-6s] cluster in different redox states.the desulfovibrio desulfuricans atcc 27774 prismane protein was isolated from a desulfovibrio vulgaris (hildenborough) strain that contained the gene for this protein in expression vector psup104. a redox titration demonstrated that the [fe-s] cluster in this protein may attain four different redox states, indicated as +3, +4, +5 and +6, with midpoint potentials for the transitions of approx. -220, +50/-25 and +370 mv, respectively. epr spectra of the protein in the various redox states are remi ...19948003528
aerobic expression of the cyf gene encoding cytochrome c-553 from desulfovibrio vulgaris hildenborough in escherichia coli.monohaem cytochrome c-553 from desulfovibrio vulgaris hildenborough is encoded by the cyf gene which could be expressed in escherichia coli to yield the periplasmic holoform of cytochrome c-553. covalent haem attachment was shown by labelling with 5-amino[4-14c]laevulinic acid, the immediate precursor for haem biosynthesis. visible-absorption spectroscopy demonstrated that the haem environment in the recombinant protein did not differ from the native protein. optimal expression was obtained unde ...19948012605
enzymatic catalysis of mercury methylation by desulfovibrio desulfuricans ls.the recently defined role of methylcobalamin in hg2+ methylation by desulfovibrio desulfuricans ls enabled us to reexamine the question of whether the principal source of methylmercury is spontaneous transmethylation or an enzymatically catalyzed process. in cell extracts of d. desulfuricans ls, over 95% of the 57co label was associated with macromolecules rather than with free cobalamin. both gel filtration and electrophoresis of cell extracts identified a single corrinoid protein of 40 kda in ...19948017921
site-directed mutagenesis of tyrosine-98 in the flavodoxin from desulfovibrio vulgaris (hildenborough): regulation of oxidation-reduction properties of the bound fmn cofactor by aromatic, solvent, and electrostatic interactions.the contributions made by tyrosine-98 in establishing the redox properties of the flavodoxin from desulfovibrio vulgaris were investigated by substituting a number of amino acids at this position using site-directed mutagenesis. tyr98, which makes extensive van der waals contacts with the isoalloxazine ring of the flavin mononucleotide cofactor, is often found in the cofactor binding site of flavodoxins and related flavoproteins. solution studies suggest that tyrosine may assist in the stabiliza ...19948031784
desulfoviridin, a multimeric-dissimilatory sulfite reductase from desulfovibrio vulgaris (hildenborough). purification, characterization, kinetics and epr studies.conditions for the rigorous purification of desulfoviridin, the dissimilatory sulfite reductase from the sulfate-reducing bacterium desulfovibrio vulgaris (hildenborough) have been established. a final purification by fast protein liquid chromatography yields at least three distinct bands that each exhibit the characteristic absorption spectrum of desulfoviridin. two of these have been extensively characterized by amino acid analysis, isoelectric focusing, polyacrylamide gel electrophoresis, and ...19948033912
isolation and characterization of a high molecular weight cytochrome from the sulfate reducing bacterium desulfovibrio gigas.a high molecular weight c-type cytochrome (hmc) was purified and characterized from desulfovibrio gigas. the molecular weight was estimated to be 67 kda by sds-page and its n-terminus is homologous to those of the 16 hemes containing high molecular weight cytochrome c from desulfovibrio vulgaris strains hildenborough and miyazaki. the purified hemoprotein shows c-type cytochrome absorption spectrum with e533 (red) = 368 a band at 640 nm, characteristic of high-spin hemes, was detected ...19948034021
functional expression and characterization of the assimilatory-type sulfite reductase from desulfovibrio vulgaris (hildenborough).by use of a conjugational transfer method, the gene encoding the assimilatory-type sulfite reductase (asir) from desulfovibrio vulgaris (hildenborough) has been functionally expressed in desulfovibrio hosts using the broad-host-range plasmid pdsk519. production is increased greater than 50-fold relative to natural expression levels. recombinant enzyme has been characterized by standard biochemical methods, nuclear magnetic resonance, electron paramagnetic resonance, electronic absorption, and ac ...19948037466
intracellular campylobacter-like organism from ferrets and hamsters with proliferative bowel disease is a desulfovibrio sp.proliferative bowel disease is an intestinal disorder of a variety of domestic animals associated with the presence of an intracellular campylobacter-like organism (iclo). we have identified the iclo obtained from a ferret with proliferative colitis by 16s rrna sequence analysis. in this ferret, proliferative bowel tissue containing the iclo had translocated to the mesenteric lymph nodes, omentum, and liver. the 16s rrna genes of the iclo were amplified from an infected fragment of extraintestin ...19948051249
membrane topology of the methyl-accepting chemotaxis protein dcra from desulfovibrio vulgaris hildenborough.alkaline phosphatase fusions were used to study the membrane topology of dcra, a protein of 668 amino acids from desulfovibrio vulgaris hildenborough, which has two potentially membrane-spanning hydrophobic sequences at residues 11 to 29 and 188 to 207. a fusion at amino acid residue 170 in the proposed periplasmic domain exhibited high alkaline phosphatase activity, while low activity was observed for a fusion at amino acid residue 284 in the proposed cytoplasmic domain. the data support a topo ...19948060126
genetic organization of the region upstream from the campylobacter jejuni flagellar gene flha.campylobacter jejuni (cj) is a gram-bacterium that causes a diarrheal disease in humans. a cj homolog of the lcrd/flha family of proteins was recently described [miller et al., infect. immun. 61 (1993) 2930-2936]. this family includes proteins that are involved in flagellar biogenesis, such as the cj flha protein, but also includes proteins found in invasive pathogens, such as the yersinia pestis lcrd protein, that play a role in the regulation and/or secretion of virulence-related proteins. hyb ...19948063102
kinetic studies on the electron-transfer reaction between cytochrome c3 and flavodoxin from desulfovibrio vulgaris strain hildenborough.the kinetic properties of the electron-transfer process between reduced desulfovibrio vulgaris cytochrome c3 and d. vulgaris flavodoxin have been studied by anaerobic stopped-flow techniques. anaerobic titrations of reduced cytochrome c3 with oxidized flavodoxin show a stoichiometry of 4 mol of flavodoxin required to oxidize the tetraheme cytochrome. flavodoxin neutral semiquinone and oxidized cytochrome c3 are the only observable products of the reaction. at ph 7.5, the four-electron-transfer r ...19948068676
homotropic and heterotropic cooperativity in the tetrahaem cytochrome c3 from desulfovibrio vulgaris.the thermodynamic parameters which govern the homotropic (e-/e-) and heterotropic (e-/h+) cooperativity in the tetrahaem cytochrome c3 isolated from desulfovibrio vulgaris (hildenborough) were determined, using the paramagnetic shifts of haem methyl groups in the nmr spectra of intermediate oxidized states at different ph levels. a model is put forward to explain how the network of positive and negative cooperativities between the four haems and acid/base group(s) enables the protein to achieve ...19948075117
1h, 15n, 13c and 13co resonance assignments and secondary structure of villin 14t, a domain conserved among actin-severing proteins.sequence-specific assignments have been made for the 1h, 15n, 13c and 13co resonances of 14t, the 126-residue amino-terminal domain of the actin-severing protein villin. villin is a member of a family of proteins that regulate cytoskeletal actin by severing, capping and nucleating actin filaments. actin binding is dependent on calcium and disrupted by phosphatidyl inositol 4,5-bisphosphate. actin-severing proteins are built from three or six repeats of a conserved domain, represented by 14t. exp ...19948075541
hncch-tocsy, a triple resonance experiment for the correlation of backbone 13c alpha and 15n resonances with aliphatic side-chain proton resonances and for measuring vicinal 13co,1h beta coupling constants in proteins.a 3d triple resonance experiment has been designed to provide intraresidual and sequential correlations between amide nitrogens and alpha-carbons in uniformly 13c/15n-labeled proteins. in-phase 13c alpha magnetization is transferred to the aliphatic side-chain protons via the side-chain carbons using a cc-tocsy mixing sequence. thus, the experiment alleviates the resonance assignment process by providing information about the amino acid type as well as establishing sequential connectivities. lea ...19948075544
synthesis and characterization of desulfovibrio gigas rubredoxin and rubredoxin fragments.the 52-residue desulfovibrio gigas rubredoxin peptide chain has been synthesized and a procedure for chain folding around iron(ii) developed. the folded, stable synthetic rubredoxin can be subjected to purification, and reversibly oxidized and reduced. ultraviolet/visible absorption and cd spectra of both forms show all the same features as native d. gigas rubredoxin, and the symmetric and asymmetric fe-s stretching bands in the resonance raman spectrum can be identified. in addition, the matrix ...19948076656
cloning, sequencing and overexpression of the desulfovibrio gigas ferredoxin gene in e. coli.we have cloned the gene encoding desulfovibrio gigas ferredoxin using a photodigoxigenin-labelled probe synthesized with the polymerase chain reaction. the dna sequence of the gene predicts a polypeptide of 58 residues after removal of the initial formyl methionine (polypeptide m(r) = 6,276). the ferredoxin gene was expressed in aerobically grown e. coli behind the lac promoter of puc18 resulting in a high level of ferredoxin expression which comprises about 10% of the total cell protein. epr an ...19948082803
purification, characterization and properties of an nadh oxidase from desulfovibrio vulgaris (hildenborough) and its coupling to adenylyl phosphosulfate nadh oxidase was purified from desulfovibrio vulgaris. this fmn-containing enzyme reacts with oxygen forming hydrogen peroxide with a specific activity of 0.21 the molecular weight of the protein was determined to be 65 kda on 12.5% sds/page. it shows very low nadh: rubredoxin oxidoreductase activity specifically towards the rubredoxin from the same organism. however, adenylyl phosphosulfate reductase can be fully reduced by nadh with the purified enzyme, suggesting that n ...19948093065
novel fmn-binding protein from desulfovibrio vulgaris (miyazaki f). cloning and expression of its gene in escherichia coli.a gene encoding a novel fmn-binding protein from desulfovibrio vulgaris (miyazaki f) was cloned, and its expression system was constructed in escherichia coli. the 1.4-kilobase pair dna fragment isolated from d. vulgaris (miyazaki f) by double digestion with kpni and smai was found to express a protein binding fmn as a prosthetic group under control of the lac promoter in e. coli. this dna fragment contained several putative open reading frames. the partial amino acid sequence of the polypeptide ...19948119891
characterization and oxidoreduction properties of cytochrome c3 after heme axial ligand replacements.cytochrome c3 (m(r) 13,000) is a tetrahemic cytochrome in which the four heme iron atoms are coordinated by 2 histidine residues at the axial positions. the presence of several oxidoreduction centers in the same molecule raises the question of their coupling. to investigate this mechanism, four single mutations were introduced in cytochrome c3 by site-directed mutagenesis, leading to the replacement of each histidine, the sixth axial ligand of the heme iron atom, by a methionine residue. charact ...19948119983
characterization and redox properties of high molecular mass cytochrome c3 (hmc) isolated from desulfovibrio vulgaris miyazaki.two kinds of high molecular mass cytochrome c3 (hmc) were isolated from desulfovibrio vulgaris miyazaki, one from the membrane (mhmc), the other from the soluble fraction (shmc). molecular masses of both hmcs determined by sds-page are 65 kda. each hmc molecule is composed of a single polypeptide chain and contains 16 hemes. shmc and mhmc have identical uv-visible absorption spectra of a typical c-type cytochrome (three peaks at 530, 419, and 355 nm in the ferri form, and four peaks at 553, 523, ...19938123705
a purified ferredoxin from giardia duodenalis.a ferredoxin has been purified to homogeneity from the ancient protozoan parasite giardia duodenalis. as far as we know, this is the first electron transport protein to be characterised from the organism. the ferredoxin exhibits absorption maxima at 296 and 406 nm with molar absorption coefficients of epsilon 296 = 16,650 +/- 240 m-1 cm-1 and epsilon 406 = 13,100 +/- 370 m-1 cm-1 respectively. the a406/a296 ratio ranged over 0.78-0.82. the molecular mass of the apoprotein calculated by mass spec ...19948125101
desulfovibrio longreachii sp. nov., a sulfate-reducing bacterium isolated from the great artesian basin of australia.a new mesophilic, thermotolerant sulfate-reducing bacterium, was isolated from the flowing bore waters of a deep aquifer, the great artesian basin, australia. the strain, designated isolate ab16910a, is a curved rod and resembled members of the genus desulfovibrio. however, the isolate can be differentiated from other members of the desulfovibrio species because of the high g+c content of 69 +/- 0.25% the 16s rrna sequence data and other physiological characteristics. the name desulfovibrio long ...19948125244
thiol/disulfide formation associated with the redox activity of the [fe3s4] cluster of desulfovibrio gigas ferredoxin ii. 1h nmr and mössbauer spectroscopic study.desulfovibrio gigas ferredoxin ii (fdii) is a small protein (alpha 4 subunit structure as isolated; m(r) approximately 6400 per subunit; 6 cysteine residues) containing one fe3s4 cluster per alpha-subunit. the x-ray structure of fdii has revealed a disulfide bridge formed by cys-18 and cys-42 approximately 13 a away from the center of the cluster; moreover, the x-ray structure indicates that cys-11 forms a disulfide bridge with a methanethiol. in the oxidized state, fdiioxm the 1h nmr spectra, e ...19948132528
redox properties of desulfovibrio gigas [fe3s4] and [fe4s4] ferredoxins and heterometal cubane-type clusters formed within the [fe3s4] core. square wave voltammetric studies.the same polypeptide chain (58 amino acids, 6 cysteines) is used to build up two ferredoxins in desulfovibrio gigas a sulfate reducing organism. ferredoxin ii (fdii) contains a single [fe3s4] core and ferredoxin i (fdi) mainly a [fe4s4] core. the [fe3s4] core can readily be interconverted into a [fe4s4] complex (j.j.g. moura, i. moura, t.a. kent, j.d. lipscomb, b.h. huynh, j. legall, a.v. xavier, and e. munck, j. biol. chem. 257, 6259 (1982)). this interconversion process suggested that the [fe3 ...19948133257
resonance raman spectroscopic evidence for the fes4 and fe-o-fe sites in rubrerythrin from desulfovibrio vulgaris.resonance raman (rr) spectra of the non-heme iron protein rubrerythrin from desulfovibrio vulgaris unequivocally demonstrate the presence of both a rubredoxin-type fes4 site and a (mu-oxo)diiron(iii) cluster. the rr spectra of rubrerythrin excited at 496.5 and 568.2 nm are dominated by bands similar to those of rubredoxin and conform to the vibrational pattern expected for a distorted fes4 tetrahedron of an fe(s-cys)4 site. numerous overtone and combination bands of the fe-s stretches are also o ...19948142354
amino-acid sequence of the cytochrome c3 (m(r) 26,000) from desulfovibrio desulfuricans norway and a comparison with those of the other polyhemic cytochromes from desulfovibrio.the amino-acid sequence of an octaheme cytochrome c3 isolated from desulfovibrio desulfuricans norway is presented. the protein molecule (m(r) 26,000) comprises two identical subunits of 111 amino acids with the characteristics typical of tetrahemic cytochrome c3 class. comparisons between the amino-acid sequences and physiological properties of cytochrome c3 (m(r) 26,000) and cytochromes c3 (m(r) 13,000) isolated from various species of desulfovibrio showed the existence of considerable differe ...19948142476
molecular cloning and sequence analysis of the gene of the molybdenum-containing aldehyde oxido-reductase of desulfovibrio gigas. the deduced amino acid sequence shows similarity to xanthine this report, we describe the isolation of a 4020-bp genomic psti fragment of desulfovibrio gigas harboring the aldehyde oxido-reductase gene. the aldehyde oxido-reductase gene spans 2718 bp of genomic dna and codes for a protein with 906 residues. the protein sequence shows an average 52% (+/- 1.5%) similarity to xanthine dehydrogenase from different organisms. the codon usage of the aldehyde oxidoreductase is almost identical to a calculated codon usage of the desulfovibrio bacteria.19948143744
primary sequence, oxidation-reduction potentials and tertiary-structure prediction of desulfovibrio desulfuricans atcc 27774 flavodoxin.flavodoxin was isolated and purified from desulfovibrio desulfuricans atcc 27774, a sulfate-reducing organism that can also utilize nitrate as an alternative electron acceptor. mid-point oxidation-reduction potentials of this flavodoxin were determined by ultraviolet/visible and epr methods coupled to potentiometric measurements and their ph dependence studied in detail. the redox potential e2, for the couple oxidized/semiquinone forms at ph 6.7 and 25 degrees c is -40 mv, while the value for th ...19948143752
spectroscopic properties of desulfoferrodoxin from desulfovibrio desulfuricans (atcc 27774).desulfoferrodoxin, a non-heme iron protein, was purified previously from extracts of desulfovibrio desulfuricans (atcc 27774) (moura, i., tavares, p., moura, j. j. g., ravi, n., huynh, b. h., liu, m.-y., and legall, j. (1990) j. biol. chem. 265, 21596-21602). the as-isolated protein displays a pink color (pink form) and contains two mononuclear iron sites in different oxidation states: a ferric site (center i) with a distorted tetrahedral sulfur coordination similar to that found in desulforedox ...19948144635
mineralization of monofluorobenzoate by a diculture under sulfate-reducing conditions.a mesophilic, dehalogenating, sulfate-reducing diculture was isolated from an anaerobic lake sediment. one strain of the diculture is proposed to be an endospore-forming desulfotomaculum species, the second strain was a vibrioid, motile and non-sporeforming species which is tentatively assigned to the genus desulfovibrio. the diculture was able to mineralize 4- and 2-fluorobenzoate both isomers being incompletely oxidized with the release of acetate, which was subsequently used by both sulfate-r ...19948150266
[taxonomic aspects of strains from patagonia and type strains of desulfovibrio].fourteen type strains and 42 indigenous strains of desulfovibrio were studied and taxonomic numeric methods were applied (cluster analysis, principal coordinates analysis, correspondence analysis). the type strains as well as the indigenous ones share a low quantity of carbon and energy sources. type strains have a taxonomic structure which shows net clusters; indigenous strains possess a grading (or "adjustment") in their positive reactions hence the taxonomic structure is not so clear. both cl ...19938153351
further characterization of the spin coupling observed in oxidized hydrogenase from chromatium vinosum. a mössbauer and multifrequency epr study.hydrogenase from chromatium vinosum contains 1 ni, 11-12 fe, and ca. 9 sulfides. epr and mössbauer studies of the enzyme prepared in four different oxidation states show that the enzyme contains two fe4s4 and one fe3s4 cluster. in the oxidized (2+) state, the mössbauer parameters of the two fe4s4 clusters are typical for this cluster type. upon reduction, however, these clusters do not exhibit the familiar g = 1.94 signal. the unusual nature of the reduced clusters is also borne out by the mössb ...19948161560
cytochrome c553 from desulfovibrio vulgaris (hildenborough). electrochemical properties and electron transfer with electrochemical study of the periplasmic cytochrome c553 of desulfovibrio vulgaris (hildenborough) is presented. the dependence of the midpoint potential on temperature and ph was studied with cyclic voltammetry. the voltammograms obtained were reversible and revealed that this cytochrome showed fast electron transfer on a bare glassy carbon electrode. the midpoint potential at ph 7.0 and 25 degrees c was found to be 62 mv versus the normal hydrogen electrode. it was observed that the tempera ...19948174562
on the iron-sulfur cluster of adenosine phosphosulfate reductase from desulfovibrio vulgaris (hildenborough).adenosine phosphosulfate reductase from desulfovibrio vulgaris hildenborough has been purified to homogeneity and was found to consist of two subunits. the alpha and beta subunits have molecular masses of 67.8 kda and 25.6 kda, respectively. the apparent molecular mass of the protein is dependent on the ionic strength of the buffer. at low ionic strength, a high molecular-mass multimer is formed, which reversibly changes into smaller units upon addition of salt. the smallest catalytically active ...19948174563
anaerobic bacteria from hypersaline environments.strictly anaerobic halophiles, namely fermentative, sulfate-reducing, homoacetogenic, phototrophic, and methanogenic bacteria are involved in the oxidation of organic carbon in hypersaline environments. to date, six anaerobic fermentative genera, containing nine species, have been described. two of them are homoacetogens. six species belong to the family haloanaerobiaceae, as indicated by their unique 16s rrna oligonucleotide sequences. desulfohalobium retbaense and desulfovibrio halophilus repr ...19948177169
solution 1h nmr determination of secondary structure for the three-iron form of ferredoxin from the hyperthermophilic archaeon pyrococcus furiosus.two-dimensional 1h nmr data have been used to make sequence-specific assignments and define the secondary structure of the three-iron form of the oxidized ferredoxin, fd, from the hyperthermophilic archaeon pyrococcus furiosus, pf. signals for at least some protons were located for 65 of the 66 amino acids in the sequence, in spite of the paramagnetic (s = 1/2) ground state, but not all could be assigned. unassigned and missing signals could be qualitatively correlated with the expected proximit ...19948193147
involvement of histidine residues in the catalytic mechanism of spite of their structural and amino acid sequence differences, fe-only and ni-containing hydrogenases achieved the same catalytic reactions. a chemical modification of histidine residues using a highly specific reagent (pentaammineruthenium ii) has been carried out on desulfovibrio vulgaris hildenborough fe-hydrogenase and desulfovibrio desulfuricans norway ni-fe-se-hydrogenase. the preliminary results obtained suggest the existence of a general mechanism involving histidine residues in the t ...19948198565
a functional heterologous electron-transfer protein complex: desulfovibrio vulgaris flavodoxin covalently linked to spinach ferredoxin-nadp+ reductase.the water-soluble carbodiimide, n-ethyl-3-(3-dimethylaminopropyl)carbodiimide was found to readily promote formation of cross-links between spinach ferredoxin-nadp+ reductase and bacterial flavodoxins. the covalent complex between ferredoxin-nadp+ reductase and the desulfovibrio vulgaris flavodoxin had a stoichiometry of 1 mol of flavodoxin per mole of the reductase, as assessed by denaturing electrophoresis, gel filtration and spectral analysis. the reductase moiety of the cross-linked complex ...19948203913
evidence for a ternary complex formed between flavodoxin and cytochrome c3: 1h-nmr and molecular modeling studies.small electron-transfer proteins such as flavodoxin (16 kda) and the tetraheme cytochrome c3 (13 kda) have been used to mimic, in vitro, part of the complex electron-transfer chain operating between substrate electron donors and respiratory electron acceptors, in sulfate-reducing bacteria (desulfovibrio species). the nature and properties of the complex formed between these proteins are revealed by 1h-nmr and molecular modeling approaches. our previous study with the desulfovibrio vulgaris prote ...19948204572
modulation of the redox properties of fmn in desulfovibrio vulgaris flavodoxin: an investigation using site-directed mutagenesis. 19948206285
aldehyde oxidoreductase activity in desulfovibrio gigas: in vitro reconstitution of an electron-transfer chain from aldehydes to the production of molecular hydrogen.the molybdenum [iron-sulfur] protein, first isolated from desulfovibrio gigas by moura et al. [moura, j. j. g., xavier, a. v., bruschi, m., le gall, j., hall, d. o., & cammack, r. (1976) biochem. biophys. res. commun. 72, 782-789], was later shown to mediate the electronic flow from salicylaldehyde to a suitable electron acceptor, 2,6-dichlorophenolindophenol (dcpip) [turner, n., barata, b., bray, r. c., deistung, j., legall, j., & moura, j. j. g. (1987) biochem. j. 243, 755-761]. the dcpip-depe ...19938218223
voltammetric studies of the catalytic electron-transfer process between the desulfovibrio gigas hydrogenase and small proteins isolated from the same genus.the kinetics of electron transfer between the desulfovibrio gigas hydrogenase and several electron-transfer proteins from desulfovibrio species were investigated by cyclic voltammetry, square-wave voltammetry and chronoamperometry. the cytochrome c3 from desulfovibrio vulgaris (hildenborough), desulfovibrio desulfuricans (norway 4), desulfovibrio desulfuricans (american type culture collection 27774) and d. gigas (ncib 9332) were used as redox carriers. they differ in their redox potentials and ...19938223656
extensive 1h nmr resonance assignment of proteins using natural abundance gradient-enhanced 13c-1h correlation spectroscopy.the reliability and completeness of 1h nmr resonance assignment can be improved by the use of 13c-1h hsqc correlation spectra on unlabelled protein samples using pulsed field gradients. this technique is illustrated on a 5.2 mm sample of the 79 residue desulfovibrio vulgaris ferrocytochrome c553. protons attached to the same carbon can be unambiguously paired in a hsqc spectrum. contrary to 1h, most amino acids exhibit characteristic 13c chemical shift ranges, which can be used for 13c assignmen ...19938224188
sequence analysis and interposon mutagenesis of the hupt gene, which encodes a sensor protein involved in repression of hydrogenase synthesis in rhodobacter capsulatus.the hupt gene, which represses hydrogenase gene expression in the purple photosynthetic bacterium rhodobacter capsulatus, has been identified and sequenced. the nucleotide sequence of hupt and of the contiguous downstream open reading frame, hupu, is reported. the hupt protein of 456 amino acids (48,414 da) has sequence similarity with the fixl, dctb, ntrb, and arcb proteins and is predicted to be a soluble sensor kinase. insertional inactivation of the hupt gene led to deregulation of transcrip ...19938226687
measurement of the net production of acidity by a sulphate-reducing bacterium: experimental checking of theoretical models of microbially influenced corrosion.the net production and consumption of acidity by desulfovibrio fructosovorans, growing with lactate as the carbon and energy source, were measured in an unbuffered medium in a ph-controlled bioreactor. at alkaline ph (7.2 and 8.5), net acidity production was measured. at ph 6.0, acidity consumption was obtained, although bacterial growth was not observed. these observations are in good agreement with theoretical predictions emphasizing the key role of h+ ions in the relationship between the meta ...19938248626
identification of cysteine ligands in metalloproteins using optical and nmr spectroscopy: cadmium-substituted rubredoxin as a model [cd(cyss)4]2- center.optical and nmr methods are presented for the identification of cysteine ligands in cd-substituted metalloproteins, in particular those containing zinc-fingerlike motifs, using cd-substituted desulfovibrio gigas rubredoxin (cd-rd) as a model [cd(cyss)4]2- complex. the 113cd nmr spectrum of cd-rd contains a single 113cd resonance with a chemical shift position (723.6 ppm) consistent with tetrathiolate metal coordination. the proton chemical shifts of the four cysteine ligands were obtained from o ...19938251947
structure analysis of cytochrome c3 from desulfovibrio vulgaris hildenborough at 1.9 a resolution.the three-dimensional x-ray structure of cytochrome c3 from sulfate-reducing bacteria desulfovibrio vulgaris hildenborough (dvh) (m(r) 13 kda, 107 residues, 4 heme groups) has been determined at 1.9 a resolution, by the method of molecular replacement, using the homologous part of the refined structure of cytochrome c3 from d. vulgaris miyazaki f (dvmf). crystals of c3 dvh were obtained with space group p61, a = 77.0 a, c = 77.2 a, z = 12, corresponding to two independent molecules in the asymme ...19938254667
on the two iron centers of desulfoferrodoxin.desulfoferrodoxin from desulfovibrio vulgaris, strain hildenborough, is a homodimer of 28 kda; it contains two fe atoms per 14.0 kda subunit. the n-terminal amino-acid sequence is homogeneous and corresponds to the previously described rho gene, which encodes a highly charged 14 kda polypeptide without a leader sequence. although one of the two iron centers, fea, has previously been described as a 'strained rubredoxin-like' site, epr of the ferric form proves very similar to that of the pentagon ...19938262195
overexpression of desulfovibrio vulgaris hildenborough cytochrome c553 in desulfovibrio desulfuricans g200. evidence of conformational heterogeneity in the oxidized protein by nmr.plasmid prc41, containing the cyf gene encoding cytochrome c533 from desulfovibrio vulgaris hildenborough, was transferred by conjugation from escherichia coli to desulfovibrio desulfuricans g200. the structural properties of the purified protein were studied by one-dimensional and two-dimensional nmr. a heterogeneity in the folding of the cytochrome isolated from d. vulgaris hildenborough and from d. desulfuricans g200 was observed for the oxidized from. temperature, ph and salt-dependence stud ...19938269917
time-resolved absorption and magnetic circular dichroism spectroscopy of cytochrome c3 from desulfovibrio.the uv-visible absorption and magnetic circular dichroism (mcd) spectra of the ferric, ferrous, co-ligated forms and kinetic photolysis intermediates of the tetraheme electron-transfer protein cytochrome c3 (cc3) are reported. consistent with bis-histidinyl axial coordination of the hemes in this class iii c-type cytochrome, the soret and visible region mcd spectra of ferric and ferrous cc3 are very similar to those of other bis-histidine axially coordinated hemeproteins such as cytochrome b5. t ...19938274660
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