Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| vertical distribution of archaea and bacteria in a meromictic lake as determined by fluorescent in situ hybridization. | the prokaryotic cells distribution in the water column of the coastal saline meromictic lake faro (messina, italy) was investigated by microscopic counting techniques. water samples were collected at a central station from the surface to the bottom, when waters were characterized by a marked stratification. a "red-water" layer, caused by a dense growth of photosynthetic sulfur bacteria, was present at a depth of 15 m, defining a transition area between oxic (mixolimnion) and anoxic (monimolimnio ... | 2012 | 22006072 |
| sodium dodecyl sulfate-polyacrylamide gel protein electrophoresis of freshwater photosynthetic sulfur bacteria. | sodium dodecyl sulfate-polyacrylamide gel protein electrophoresis (sds-page) was carried out using different bacterial strains of the photosynthetic sulfur bacteria chlorobium, thiocapsa, thiocystis, and chromatium cultured in the laboratory, and the natural blooms in two karstic lakes (lake cisó and lake vilar, ne spain) where planktonic photosynthetic bacteria (purple and green sulfur bacteria) massively developed accounting for most of the microbial biomass. several extraction, solubilization ... | 2011 | 20524118 |
| investigation of the redox interaction between mn-bicarbonate complexes and reaction centers from rhodobacter sphaeroides r-26, chromatium minutissimum, and chloroflexus aurantiacus. | the change in the dark reduction rate of photooxidized reaction centers (rc) of type ii from three anoxygenic bacteria (rhodobacter sphaeroides r-26, chromatium minutissimum, and chloroflexus aurantiacus) having different redox potentials of the p(+)/p pair and availability of rc for exogenous electron donors was investigated upon the addition of mn(2+) and hco(3)(-). it was found that the dark reduction of p(870)(+) from rb. sphaeroides r-26 is considerably accelerated upon the combined additio ... | 2011 | 22150281 |
| [physilogical and biochemical properties of bacteria of chromatium genus, isolated from water bodies enriched with hydrogen sulfide]. | pure cultures of purple sulfur bacteria, which were attributed to genus chromatium, were isolated from water bodies of the yavoriv sulfur deposit. both cultures perform anoxygenic photosynthesis and contain bacteriochlorophyll a and carotenoids of spirilloxanthin group. isolated bacteria grow photolithoauthotrophically, photolithoheterotrophically and photoorganoheterotrophically. hydrogen sulphide, sulfur and thiosulfate were used as inorganic electron donors. bacteria were resistant to high hy ... | 2009 | 20455432 |
| co-occurrence of denitrification and nitrogen fixation in a meromictic lake, lake cadagno (switzerland). | the nitrogen cycling of lake cadagno was investigated by using a combination of biogeochemical and molecular ecological techniques. in the upper oxic freshwater zone inorganic nitrogen concentrations were low (up to approximately 3.4 microm nitrate at the base of the oxic zone), while in the lower anoxic zone there were high concentrations of ammonium (up to 40 microm). between these zones, a narrow zone was characterized by no measurable inorganic nitrogen, but high microbial biomass (up to 4 x ... | 2009 | 19397681 |
| unexpected extracellular and intracellular sulfur species during growth of allochromatium vinosum with reduced sulfur compounds. | before its uptake and oxidation by purple sulfur bacteria, elemental sulfur probably first has to be mobilized. to obtain more insight into this mobilization process in the phototrophic purple sulfur bacterium allochromatium vinosum, we used hplc analysis and x-ray absorption near-edge structure (xanes) spectroscopy for the detection and identification of sulfur compounds in culture supernatants and bacterial cells. we intended to identify soluble sulfur compounds that specifically occur during ... | 2009 | 19423634 |
| chromatium species: an emerging bioindicator of crude oil pollution of tidal mud flats in the niger delta mangrove ecosystem, nigeria. | establishing microbiological indices for the monitoring of environmental decay by crude oil pollution in the niger delta region has been a major concern of our current researches. chromatium species, a purple, gram positive pleomorphic, motile, microaerophlic sulfur bacterium offers a good potential for use in the assessment of the short term effects of oil pollution of tidal mud flats in the niger delta mangrove ecosystem. its response to the november 22, 2003 spillage at the qua iboe estuary a ... | 2009 | 18600468 |
| epigenetics in acute myeloid leukemia. | acute myeloid leukemia (aml) is a disease characterized by uncontrolled proliferation of clonal neoplastic hematopoietic precursor cells. this leads to the disruption of normal hematopoiesis and bone marrow failure. major breakthroughs in the past have contributed to our understanding of the genetic failures and the changed biology in aml cells that underlie the initiation and progression of the disease. it is now recognized that not only genetic but also epigenetic alterations are similarly imp ... | 2008 | 18692688 |
| thiophaeococcus mangrovi gen. nov., sp. nov., a photosynthetic, marine gammaproteobacterium isolated from the bhitarkanika mangrove forest of india. | a coccoid, phototrophic purple sulfur bacterium was isolated in pure culture from a mud sample collected from brackish water in the bhitarkanika mangrove forest of orissa, india, in a medium containing 2 % nacl (w/v). this bacterium, strain ja304(t), was gram-negative and had a requirement for nacl. intracellular photosynthetic membranes were of the vesicular type. the colour of the phototrophically grown culture was saddle-brown. bacteriochlorophyll a and the carotenoid lycopene were present as ... | 2008 | 18984710 |
| a single-cell view on the ecophysiology of anaerobic phototrophic bacteria. | quantitative information on the ecophysiology of individual microorganisms is generally limited because it is difficult to assign specific metabolic activities to identified single cells. here, we develop and apply a method, halogen in situ hybridization-secondary ion mass spectroscopy (hish-sims), and show that it allows simultaneous phylogenetic identification and quantitation of metabolic activities of single microbial cells in the environment. using hish-sims, individual cells of the anaerob ... | 2008 | 19004766 |
| dynamics of electron transfer from high-potential cytochrome c to bacteriochlorophyll dimer in photosynthetic reaction centers as probed using laser-induced temperature jump. | laser-induced temperature jump experiments were used for testing the rates of thermoinduced conformational transitions of reaction center (rc) complexes in chromatophores of chromatium minutissimum. the thermoinduced transition of the macromolecular rc complex to a state providing effective electron transport from the multiheme cytochrome c to the photoactive bacteriochlorophyll dimer within the temperature range 220-280 k accounts for tens of seconds with activation energy 0.166 ev/molecule. th ... | 2007 | 17262223 |
| utilization of solid "elemental" sulfur by the phototrophic purple sulfur bacterium allochromatium vinosum: a sulfur k-edge x-ray absorption spectroscopy study. | the purple sulfur bacterium allochromatium vinosum can use elemental sulfur as an electron donor for anoxygenic photosynthesis. the elemental sulfur is taken up, transformed into intracellular sulfur globules and oxidized to sulfate. commercially available "elemental" sulfur usually consists of the two species cyclo-octasulfur and polymeric sulfur. the authors investigated whether only one sulfur species is used or at least preferred when alc. vinosum takes up elemental sulfur and forms globules ... | 2007 | 17379736 |
| [purple sulfur bacteria isolated from reservoirs of the yavoriv sulfur deposit]. | three pure cultures of purple sulfur bacteria were isolated from reservoirs of the yavoriv sulfur deposit. the studying of their morphology, cytology and physiology has confirmed the belonging of these bacteria to chromatiaceae family and has allowed identifying them as thiocapsa sp., lamprocystis sp. and chromatium sp. | 2007 | 17427405 |
| understanding nicotinamide dinucleotide cofactor and substrate specificity in class i flavoprotein disulfide oxidoreductases: crystallographic analysis of a glutathione amide reductase. | glutathione reductase (gr) plays a vital role in maintaining the antioxidant levels of the cytoplasm by catalyzing the reduction of glutathione disulfide to reduced glutathione, thereby using nadph and flavin adenine dinucleotide as cofactors. chromatiaceae have evolved an unusual homolog that prefers both a modified substrate (glutathione amide disulfide [gassag]) and a different cofactor (nadh). herein, we present the crystal structure of the chromatium gracile glutathione amide reductase (gar ... | 2007 | 17977556 |
| granulosicoccaceae fam. nov., to include granulosicoccus antarcticus gen. nov., sp. nov., a non-phototrophic, obligately aerobic chemoheterotroph in the order chromatiales, isolated from antarctic seawater. | a gram-negative, motile by tuft flagella, obligately aerobic chemoorganoheterotrophic, sphere-form bacterium, designated imcc3135(t), was isolated from the antarctic surface seawater of king george island, west antarctica. the strain was mesophilic, neutrophilic, and requiring nacl for growth, but neither halophilic nor halotolerant. the 16s rrna gene sequence analysis indicated that the strain was most closely related to genera of the order chromatiales in the class gammaproteobacteria. the mos ... | 2007 | 18062226 |
| [ni(xbsms)ru(co)2cl2]: a bioinspired nickel-ruthenium functional model of [nife] hydrogenase. | as a model of the active site of [nife] hydrogenases, a dinuclear nickel-ruthenium complex [ni(xbsms)ru(co)2cl2] was synthesized and fully characterized. the three-dimensional structure reveals a nickel center in a square-planar dithioether-dithiolate environment connected to a ruthenium moiety via a ni(mu-sr)2ru bridge. this complex catalyzes hydrogen evolution by electroreduction of the weakly acidic et3nh+ ions in n,n-dimethylformamide and is therefore the first functional bioinspired model o ... | 2006 | 16711679 |
| reducing red color intensity of seafood wastewater in facultative pond. | studies were carried out on the growth of chromatium sp. on seafood wastewater (sfww), which under facultative conditions and light exposure produced red pigment. the strain grew and utilized organic matter in both dark and light exposure conditions, but it produced red pigment when exposed to light. the growth was repressed by aerobic condition. the red color intensity was reduced by about 32.5+/-1.5 and 70.8+/-2.8% when kept under dark and static conditions, or aerobic and light exposure condi ... | 2006 | 16154743 |
| carotenoid-bacteriochlorophyll energy transfer in lh2 complexes studied with 10-fs time resolution. | in this report, we present a study of carotenoid-bacteriochlorophyll energy transfer processes in two peripheral light-harvesting complexes (known as lh2) from purple bacteria. we use transient absorption spectroscopy with approximately 10 fs temporal resolution, which is necessary to observe the very fast energy relaxation processes. by comparing excited-state dynamics of the carotenoids in organic solvents and inside the lh2 complexes, it has been possible to directly evaluate their energy tra ... | 2006 | 16428274 |
| successful recombinant production of allochromatium vinosum cytochrome c' requires coexpression of cmm genes in heme-rich escherichia coli jcb712. | cytochrome c' from the purple photosynthetic bacterium allochromatium vinosum (ccp) displays a unique, reversible dimer-to-monomer transition upon binding of no, co, and cn(-). this small, four helix bundle protein represents an attractive model for the study of other heme protein biosensors, provided a recombinant expression system is available. here we report the development of an efficient expression system for ccp that makes use of a maltose binding protein fusion strategy to enhance peripla ... | 2005 | 15649399 |
| [ecophysiological properties of photosynthesizing bacteria from the black sea chemocline zone]. | in may 1998, during the fifty-first voyage on board the research vessel professor vodyanitskii, a comparative study was conducted of the species diversity of green and purple sulfur bacteria in the water column of the chemocline zone at deep-sea stations and on the bottom surface of the black sea shallow regions. at three deep-sea stations, the accumulation of photosynthesizing bacteria in the chemocline zone at a depth of 85-115 m was revealed on the basis of the distribution of potential value ... | 2005 | 15938401 |
| long-term population dynamics of phototrophic sulfur bacteria in the chemocline of lake cadagno, switzerland. | population analyses in water samples obtained from the chemocline of crenogenic, meromictic lake cadagno, switzerland, in october for the years 1994 to 2003 were studied using in situ hybridization with specific probes. during this 10-year period, large shifts in abundance between purple and green sulfur bacteria and among different populations were obtained. purple sulfur bacteria were the numerically most prominent phototrophic sulfur bacteria in samples obtained from 1994 to 2001, when they r ... | 2005 | 16000760 |
| phototrophic purple bacterium chromatium minutissimum does not synthesize cytokinins under optimal growth conditions. | 2003 | 15255204 | |
| effect of duckweed cover on greenhouse gas emissions and odour release from waste stabilisation ponds. | treatment of wastewater in stabilisation pond systems prevents the negative environmental impact of uncontrolled disposal of sewage. however, even a natural treatment system may generate secondary negative environmental impacts in terms of energy consumption, emission of greenhouse gases and emission of odorous compounds. whereas natural systems have an advantage over electro-mechanical systems in that they use less hardware and less energy, it is not yet known whether secondary environmental ef ... | 2003 | 14510229 |
| investigation of the reduced high-potential iron-sulfur protein from chromatium vinosum and relevant model compounds: a unified picture of the electronic structure of [fe(4)s(4)](2+) systems through magnetic and optical studies. | magnetization measurements and variable temperature optical spectroscopy have been used to investigate, within the 4-300 k temperature range, the electronic structure of the reduced high-potential iron protein (hipip) from chromatium vinosum and the model compounds (cat)(2)[fe(4)s(4)(sr)(4)], where rs(-) = 2,4,6-triisopropylphenylthiolate (1), 2,6-diphenylphenylthiolate (2), diphenylmethylthiolate (3), 2,4,6-triisopropylbenzylthiolate (4, 4'), 2,4,6-triphenylbenzylthiolate (5, 5'), 2,4,6-tri-ter ... | 2003 | 14552635 |
| selective staining of proteins with hydrophobic surface sites on a native electrophoretic gel. | chemical proteomics aims to characterize all of the proteins in the proteome with respect to their function, which is associated with their interaction with other molecules. we propose the identification of a subproteomic library of expressed proteins whose native structures are typified by the presence of hydrophobic surface sites, which are often involved in interactions with small molecules, membrane lipids, and other proteins, pertaining to their functions. we demonstrate that soluble globul ... | 2003 | 14582643 |
| spatio-temporal distribution of phototrophic sulfur bacteria in the chemocline of meromictic lake cadagno (switzerland). | abstract in situ hybridization was used to study the spatio-temporal distribution of phototrophic sulfur bacteria in the permanent chemocline of meromictic lake cadagno, switzerland. at all four sampling times during the year the numerically most important phototrophic sulfur bacteria in the chemocline were small-celled purple sulfur bacteria of two yet uncultured populations designated d and f. other small-celled purple sulfur bacteria (amoebobacter purpureus and lamprocystis roseopersicina) we ... | 2003 | 19719699 |
| the crystal structure of a 26-nucleotide rna containing a hook-turn. | a crystal structure has been obtained for a 26-nucleotide rna that contains the loop e sequence from chromatium minutissimum. rather than having a loop e-like conformation, it consists of an a-form helix that splits into two separate strands following a sheared a-g base pair. the backbone of the strand containing the g of the a-g pair makes a turn of almost 180 degrees in the space of two nucleotides, and then interacts with the minor groove of the helix from which it originates. similar structu ... | 2003 | 12554875 |
| reconstitution of carotenoids into the light-harvesting complex b800-850 of chromatium minutissimum. | chromatophores and peripheral light-harvesting complexes b800-850 with a trace of carotenoids were isolated from chromatium minutissimum cells in which carotenoid biosynthesis was inhibited by diphenylamine. three methods previously used for the reconstitution of carotenoids into either the light-harvesting (lh1) type complexes or reaction centers (rc) of carotenoidless mutants were examined for the possibility of carotenoid reconstitution into the carotenoid depleted chromatophores. all these m ... | 2003 | 12948391 |
| azotobacter vinelandii ferredoxin i: a sequence and structure comparison approach to alteration of [4fe-4s]2+/+ reduction potential. | the reduction potential (e(0)') of the [4fe-4s](2+/+) cluster of azotobacter vinelandii ferredoxin i (avfdi) and related ferredoxins is approximately 200 mv more negative than the corresponding clusters of peptostreptococcus asaccharolyticus ferredoxin and related ferredoxins. previous studies have shown that these differences in e(0)' do not result from the presence or absence of negatively charged surface residues or in differences in the types of hydrophobic residues found close to the [4fe-4 ... | 2002 | 11704670 |
| crystal structure and stability studies of c77s hipip: a serine ligated [4fe-4s] cluster. | the crystal structure of chromatium vinosum c77s hipip has been determined and is compared with that of wild type. this is the first reported crystal structure of a ser ligated [4fe-4s] cluster and reveals a 0.11 a shortening of the fe-o bond (relative to fe-s), but only minor structural alterations of the overall tertiary structure. coordination changes are corroborated by resonance raman spectroscopy. comparison of the crystal and solution structures for hipips identifies phe48 as the main con ... | 2002 | 11802718 |
| crystallization and preliminary x-ray crystallographic analysis of glutathione amide reductase from chromatium gracile. | the chromatiaceae-specific glutathione amide reductase (gar) belongs to the well known family of the glutathione reductases, even though differences in both substrate (glutathione amide instead of glutathione) and coenzyme (nadh instead of nadph) specificities are reported. crystals of the gar enzyme from chromatium gracile have been grown at 294 k by the hanging-drop vapour-diffusion method using lithium sulfate as a precipitant in the presence of nickel ions. the crystals belong to space group ... | 2002 | 11807270 |
| redox-related chemical shift perturbations on backbone nuclei of high-potential iron-sulfur proteins. | 2002 | 11896740 | |
| n-terminal methylation of the core light-harvesting complex in purple photosynthetic bacteria. | several core light-harvesting complexes from both sulfur and non-sulfur purple photosynthetic bacteria have been identified to be methylated at the n-terminal alpha-amino group of beta-polypeptides by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nuclear magnetic resonance. monomethylation has been confirmed for the n-terminal alanine residues of the beta-polypeptides from rhodospirillum rubrum, thermochromatium tepidum and chromatium vinosum, but not for ... | 2002 | 12023037 |
| the role of high-potential iron protein and cytochrome c(8) as alternative electron donors to the reaction center of chromatium vinosum. | under anaerobic conditions, intact cells of the purple sulfur bacterium chromatium vinosum exhibit rapid photooxidation of the two low-potential hemes of the c-type cytochrome associated with the reaction center, after exposure to two short light flashes separated by a dark interval. reduction of the photooxidized low-potential hemes is very slow under these conditions. on subsequent flashes, rapid photooxidation of a high-potential reaction center heme occurs and is followed by its rereduction ... | 2002 | 12102629 |
| genetic construction of truncated and chimeric metalloproteins derived from the alpha subunit of acetyl-coa synthase from clostridium thermoaceticum. | in this study, a genetics-based method is used to truncate acetyl-coenzyme a synthase from clostridium thermoaceticum (acs), an alpha(2)beta(2) tetrameric 310 kda bifunctional enzyme. acs catalyzes the reversible reduction of co(2) to co and the synthesis of acetyl-coa from co (or co(2) in the presence of low-potential reductants), coa, and a methyl group bound to a corrinoid-iron sulfur protein (cofesp). acs contains seven metal-sulfur clusters of four different types called a, b, c, and d. the ... | 2002 | 12121109 |
| direct comparison of the electrocatalytic oxidation of hydrogen by an enzyme and a platinum catalyst. | it is shown that for molecules of allochromatium vinosum [nife]-hydrogenase adsorbed on a pyrolytic graphite electrode the nickel-iron active site catalyzes hydrogen oxidation at a diffusion-controlled rate matching that achieved by platinum. | 2002 | 12123018 |
| dynamics of wild-type hipips: a cys77ser mutant and a partially unfolded hipip. | the temperature dependence of the mean square displacement of the (57)fe nuclei due to motion faster than 100 ns are measured by temperature-dependent mössbauer spectroscopy for oxidized and reduced hipips from ectothiorhodospira halophila, chromatium vinosum wt and a cys77ser mutant. the behaviour is interpretable in the frame of the general model of protein dynamics distinguishing two temperature intervals. the character of harmonic and quasi-diffusional modes in hipips is discussed. dynamic i ... | 2002 | 12203006 |
| cloning a gene encoding a light-harvesting i polypeptide from ectothiorhodospira sp. | trying to detect the genes coding for light harvesting ii polypeptides of the purple bacteria ectothiorhodospira sp. a gene corresponding to a light harvesting i polypeptide was cloned. this paper discusses the probable reasons of this result. the sequence of this polypeptide underlines the strong similarity with light harvesting complexes from bacteria such as rhodospirillum molischianum and chromatium vinosum. | 2002 | 12240998 |
| mechanism and biological role of nitric oxide binding to cytochrome c'. | the binding of nitric oxide to ferric and ferrous chromatium vinosum cytochrome c' was studied. the extinction coefficients for the ferric and ferrous nitric oxide complexes were measured. a binding model that included both a conformational change and dissociation of the dimer into subunits provided the best fit for the ferric cytochrome c' data. the no (nitric oxide) binding affinity of the wt ferric form was found to be comparable to the affinities displayed by the ferric myoglobins and hemogl ... | 2002 | 12269801 |
| fluorescence of native and carotenoid-depleted lh2 from chromatium minutissimum, originating from simultaneous two-photon absorption in the spectral range of the presumed (optically 'dark') s(1) state of carotenoids. | native and carotenoid-depleted peripheral purple bacterial light-harvesting complex (lh2) were investigated by simultaneous two-photon excited (between 1300-1500 nm) fluorescence (tpf). tpf results from direct bacteriochlorophyll excitation in both samples. the spectral position of the 2a(g)(-) state of rhodopin [corrected] is indicated by a diminuition of the bacteriochlorophyll tpf in native lh2. in conclusion, comparison to carotenoid-depleted samples is a conditio sine qua non for unambiguou ... | 2002 | 12297310 |
| predatory prokaryotes: an emerging research opportunity. | predatory prokaryotes have evolved a unique strategy of obtaining energy and biosynthetic materials from their surroundings: acquiring them from other living bacterial cells. these types of microbes have been found in a diverse variety of environments, and may play an important role in modulating microbial population structure and dynamics, as has been hypothesized for marine viruses and possibly protists. only one genus of predatory bacterium, bdellovibrio, has been extensively described and st ... | 2002 | 12432957 |
| [two-photon excitation fluorescence spectrum of the light-harvesting complex lh2 from chromatium minutissimum within 650-745 nm range is determined by two-photon absorption of bacteriochlorophyll rather than of carotenoids]. | two-photon fluorescence excitation spectra of the peripheral light-harvesting complex lh2 from the purple photosynthetic bacterium chromatium minutissimum were examined within the expected spectral range of the optically forbidden s1 singlet state of carotenoids. lh2 preparations isolated from wild-type and carotenoid-depleted cells were used. 100-fs laser pulses in the range of 1300-1490 nm with an energy of 7-9 mw (corresponding to one-photon absorption between 650 and 745 nm) were used for tw ... | 2002 | 12500564 |
| transcription of three sets of genes coding for the core light-harvesting proteins in the purple sulfur bacterium, allochromatium vinosum. | the nucleotide sequence of the puf operon coding for the subunits of the photosynthetic reaction center and the core light-harvesting complex (lh1) of the purple sulfur bacterium, allochromatium (a.) vinosum (formally chromatium vinosum), was completely determined. unlike other known puf operons, which contain only one set of genes coding for the lh1 apoproteins, pufb and pufa, the a. vinosum puf operon included three sets of pufb and pufa genes with a gene order of pufb (1) a (1) lmcb (2) a (2) ... | 2002 | 16245138 |
| effect of carotenoids on the interaction between pigment-protein complexes in membranes of the sulfur photosynthetic bacterium chromatium minutissimum. | 2001 | 11813560 | |
| the [nife] hydrogenase from allochromatium vinosum studied in epr-detectable states: h/d exchange experiments that yield new information about the structure of the active site. | in this study we report on thus-far unobserved proton hyperfine couplings in the well-known epr signals of [nife] hydrogenases. the preparation of the enzyme in several highly homogeneous states allowed us to carefully re-examine the ni(u)*, ni(r)*, ni(a)-c* and ni(a)-l* epr signals which are present in most [nife] hydrogenases. at high resolution (modulation amplitude 0.57 g), clear indications for hyperfine interactions were observed in the g(z) line of the ni(r)* epr signal. the hyperfine pat ... | 2001 | 11713683 |
| steady-state and time-resolved fluorescence studies on wild type and mutant chromatium vinosum high potential iron proteins: holo- and apo-forms. | detailed circular dichroism (cd), steady-state and time-resolved tryptophan fluorescence studies on the holo- and apo- forms of high potential iron protein (hipip) from chromatium vinosum and its mutant protein have been carried out to investigate conformational properties of the protein. cd studies showed that the protein does not have any significant secondary structure elements in the holo- or apo- hipip, indicating that the metal cluster does not have any effect on formation of secondary str ... | 2001 | 11566801 |
| spectroscopic and functional properties of novel 2[4fe-4s] cluster-containing ferredoxins from the green sulfur bacterium chlorobium tepidum. | two distinct ferredoxins, fd i and fd ii, were isolated and purified to homogeneity from photoautotrophically grown chlorobium tepidum, a moderately thermophilic green sulfur bacterium that assimilates carbon dioxide by the reductive tricarboxylic acid cycle. both ferredoxins serve a crucial role as electron donors for reductive carboxylation, catalyzed by a key enzyme of this pathway, pyruvate synthase/pyruvate ferredoxin oxidoreductase. the reduction potentials of fd i and fd ii were determine ... | 2001 | 11568186 |
| comparison and characterization of the [fe4s4]2+/3+ centre in the wild-type and c77s mutated hipips from chromatium vinosum monitored by mössbauer, 57fe endor and epr spectroscopies. | mössbauer, 57fe endor, cw and pulsed epr experiments were performed on the reduced and the oxidized high-potential iron proteins (hipips) of the wild type (wt) and the c77s mutant from chromatium vinosum. the epr spectra of the oxidized wt and mutant show three species respectively having nearly the same g-values but strongly changed spectral contributions. relaxation times were estimated for oxidized wt and mutant at t = 5 k with pulsed epr. a-tensor components of both iron pairs were obtained ... | 2001 | 11315559 |
| elucidation of a [4fe-4s] cluster degradation pathway: rapid kinetic studies of the degradation of chromatium vinosum hipip. | irreversible disassembly of the 4fe-4s cluster in chromatium vinosum high-potential iron protein (hipip) has been investigated in the presence of a low concentration of guanidinium hydrochloride. from the dependence of degradation rate on [h+], it is deduced that at least three protons are required to trigger efficient cluster degradation. under these conditions the protonated cluster shows broadened mössbauer signals, but delta eq (1.1 mm/s) and delta (0.44 mm/s) are similar to the native form. ... | 2001 | 11315562 |
| intramolecular electron transfer in [4fe-4s] proteins: estimates of the reorganization energy and electronic coupling in chromatium vinosum ferredoxin. | the semi-classical electron transfer theory has been very successful in describing reactions occurring in biological systems, but the relevant parameters in the case of iron-sulfur proteins remain unknown. the recent discovery that 2[4fe-4s] proteins homologous to chromatium vinosum ferredoxin contain clusters with different reduction potentials now gives the opportunity to study the dependence of the intramolecular electron transfer rate between these clusters as a function of the driving force ... | 2001 | 11372203 |
| characterization of clutathione amide reductase from chromatium gracile. identification of a novel thiol peroxidase (prx/grx) fueled by glutathione amide redox cycling. | among the chromatiaceae, the glutathione derivative gamma-l-glutamyl-l-cysteinylglycine amide, or glutathione amide, was reported to be present in facultative aerobic as well as in strictly anaerobic species. the gene (garb) encoding the central enzyme in glutathione amide cycling, glutathione amide reductase (gar), has been isolated from chromatium gracile, and its genomic organization has been examined. the garb gene is immediately preceded by an open reading frame encoding a novel 27.5-kda ch ... | 2001 | 11399772 |
| first observation by mass spectrometry of a 3+ oxidation state for a [4fe-4s] metalloprotein: an esi-fticr mass spectrometry study of the high potential iron-sulfur protein from chromatium vinosum. | electrospray ionization (esi) fourier transform ion cyclotron resonance mass spectrometry (fticr) is used to measure the molecular weight of the high potential iron-sulfur protein (hipip) from chromatium vinosum (c. vinosum) and its corresponding apoprotein. by accurate mass measurement of the metalloprotein, the oxidation state of the [4fe-4s] metal center is assigned as 3+. this is the highest oxidation state yet observed by mass spectrometry for a [4fe-4s] cluster, which usually appears in th ... | 2001 | 11444604 |
| uv-induced destruction of light-harvesting complexes from purple bacterium chromatium minutissimum. | we studied uv-induced photodestruction of the native forms of bacteriochlorophyll a (bchl a) from chromatophores and light harvesting complexes (lhc) of the sulphur photosynthetic bacterium chromatium minutissimum. irradiation of chromato- phores with 365-nm light (soret band) or 280-nm light (absorption region of aromatic amino acids) led to the destruction of all long-wavelength forms of bchl a. the quantum yields of photodestruction produced by the 280-nm light was higher than that produced b ... | 2001 | 11497101 |
| mechanistic studies on class i polyhydroxybutyrate (phb) synthase from ralstonia eutropha: class i and iii synthases share a similar catalytic mechanism. | the class i and iii polyhydroxybutyrate (phb) synthases from ralstonia eutropha and chromatium vinosum, respectively, catalyze the polymerization of beta-hydroxybutyryl-coenzyme a (hbcoa) to generate phb. these synthases have different molecular weights, subunit composition, and kinetic properties. recent studies with the c. vinosum synthase suggested that it is structurally homologous to bacterial lipases and allowed identification of active site residues important for catalysis [jia, y., kappo ... | 2001 | 11170423 |
| model of detergent-induced spectral changes of the b800-850 complex from chromatium minutissimum. | the absorption and circular dichroism spectra of the b800-850 complex from chromatium minutissimum before and after the triton x-100 treatment were simulated by means of standard exciton theory, taking into account inhomogeneous broadening. to explain the spectral changes of the b800-850 complex treated with triton x-100, we have assumed that all bacteriochlorophyll pigments absorbing at 850 nm exhibit the same additional rotation of approximately 20 degrees around the axis perpendicular to the ... | 2000 | 11185955 |
| lipases provide a new mechanistic model for polyhydroxybutyrate (phb) synthases: characterization of the functional residues in chromatium vinosum phb synthase. | polyhydroxybutyrate (phb) synthases catalyze the conversion of beta-hydroxybutyryl coenzyme a (hbcoa) to phb. these enzymes require an active site cysteine nucleophile for covalent catalysis. a protein blastp search using the class iii chromatium vinosum synthase sequence reveals high homology to prokaryotic lipases whose crystal structures are known. the homology is very convincing in the alpha-beta-elbow (with the active site nucleophile)-alpha-beta structure, residues 131-175 of the synthase. ... | 2000 | 10747780 |
| unusual spectroscopic and electrochemical properties of the 2[4fe-4s] ferredoxin of thauera aromatica. | a reduced ferredoxin serves as the natural electron donor for key enzymes of the anaerobic aromatic metabolism in the denitrifying bacterium thauera aromatica. it contains two [4fe-4s] clusters and belongs to the chromatium vinosum type of ferredoxins (cvfd) which differ from the "clostridial" type by a six-amino acid insertion between two successive cysteines and a c-terminal alpha-helical amino acid extension. the electrochemical and electron paramagnetic resonance (epr) spectroscopic properti ... | 2000 | 10769152 |
| crystallization and preliminary crystallographic analysis of the high-potential iron-sulfur protein from thermochromatium tepidum. | the high-potential iron-sulfur protein (hipip) is an electron carrier between the photosynthetic reaction centre and the cytochrome bc(1) complex in the electron-transfer chain of photosynthesis. the purified hipip from thermochromatium tepidum (formerly chromatium tepidum) was crystallized in a solution of 1.4 m ammonium sulfate and 0.1 m sodium citrate ph 3.5. the crystals diffract x-rays beyond 1.4 a resolution and belong to the orthorhombic space group p2(1)2(1)2(1), with unit-cell parameter ... | 2000 | 10771441 |
| a membrane-bound flavocytochrome c-sulfide dehydrogenase from the purple phototrophic sulfur bacterium ectothiorhodospira vacuolata. | the amino acid sequence of ectothiorhodospira vacuolata cytochrome c-552, isolated from membranes with n-butanol, shows that it is a protein of 77 amino acid residues with a molecular mass of 9,041 da. it is closely related to the cytochrome subunit of chlorobium limicola f. sp. thiosulfatophilum flavocytochrome c-sulfide dehydrogenase (fcsd), having 49% identity. these data allowed isolation of a 5.5-kb subgenomic clone which contains the cytochrome gene and an adjacent flavoprotein gene as in ... | 2000 | 10809687 |
| exploitation of butyrate kinase and phosphotransbutyrylase from clostridium acetobutylicum for the in vitro biosynthesis of poly(hydroxyalkanoic acid). | active butyrate kinase (buk) and phosphotransbutyrylase (ptb) were purified in three steps: ammonium sulfate precipitation, hydrophobic chromatography on phenyl-sepharose and affinity chromatography on matrex red a from recombinant escherichia coli k2006 (pjc7). they were then successfully exploited for in vitro synthesis of 3-hydroxybutyryl-coa (3hbcoa), 4-hydroxybutyryl-coa (4hbcoa), 4-hydroxyvaleryl-coa (4hvcoa) and poly(hydroxyalkanoic acid) (pha). in addition, the ability of the pha synthas ... | 2000 | 10855714 |
| structural examination of the nickel site in chromatium vinosum hydrogenase: redox state oscillations and structural changes accompanying reductive activation and co binding. | an x-ray absorption spectroscopic study of structural changes occurring at the ni site of chromatium vinosum hydrogenase during reductive activation, co binding, and photolysis is presented. structural details of the ni sites for the ready silent intermediate state, si(r), and the carbon monoxide complex, si-co, are presented for the first time in any hydrogenase. analysis of nickel k-edge energy shifts in redox-related samples reveals that reductive activation is accompanied by an oscillation i ... | 2000 | 10858296 |
| complex formation between chromatium vinosum ferric cytochrome c' and bromophenol blue. | an unusual complex has been observed between the common electrophoresis tracer bromophenol blue (bpb) and the cytochrome c' from chromatium vinosum during polyacrylamide gel electrophoresis. complex formation results in a shift and increase in the intensity of the visible absorption band of bpb. differential spectrophotometric titration of bpb with cytochrome c' indicates that one bpb binds to each of the two subunits of cytochrome c' with a binding constant of 4.2(0.5) x 10(5). the absence of a ... | 2000 | 10871042 |
| [the activity of the carbon metabolism enzymes in chromatium minutissimum after long-term preservation]. | the activity of the enzymes of the tricarboxylic acid cycle and glyoxylate shunt, as well as of some enzymes involved in carbohydrate metabolism, were determined in the purple sulfur bacterium chromatium minutissimum, either maintained by subculturing in liquid medium or stored in the lyophilized state for 36 years. in cultures stored in the lyophilized state, the activities of the key enzymes of the tricarboxylic acid cycle, glyoxylate shunt, and embden-meyerhof-parnas pathway were higher, wher ... | 2000 | 10920800 |
| characterization of the cys gene locus from allochromatium vinosum indicates an unusual sulfate assimilation pathway. | homologues of the genes cysb, cysi, cysh, cysd, cysn, and seld were identified in the genome of the phototrophic purple sulfur bacterium allochromatium vinosum (formerly chromatium vinosum). on the basis of amino acid comparisons these genes encode a ferredoxin-dependent siroheme-sulfite reductase (cysi), a plant-type assimilatory aps reductase without thioredoxin domain (cysh), the two different subunits of heterodimeric atp sulfurylase (cysdn), a transcriptional regulator (cysb) and a selenoph ... | 2000 | 10939523 |
| model-free analysis of a thermophilic fe(7)s(8) protein compared with a mesophilic fe(4)s(4) protein. | 15n t(1), t(2) and (1)h-(15)n noe were measured for the thermophilic fe(7)s(8) protein from bacillus schlegelii and for the fe(4)s(4) hipip protein from chromatium vinosum, which is a mesophilic protein. the investigation was performed at 276, 300, and 330 k at 11.7 t for the former, whereas only the 298 k data at 14.1 t for the latter were acquired. the data were analyzed with the model-free protocol after correcting the measured parameters for the effect of paramagnetism, because both proteins ... | 2000 | 10944395 |
| analysis of the thiocapsa pfennigii polyhydroxyalkanoate synthase: subcloning, molecular characterization and generation of hybrid synthases with the corresponding chromatium vinosum enzyme. | the pha synthase structural gene of thiocapsa pfennigii was identified and subcloned on a 2.8-kbp bamhi restriction fragment, which was cloned recently from a genomic 15.6-kbp ecori restriction fragment. nucleotide sequence analysis of this fragment revealed three open reading frames (orfs), representing coding regions. two orfs encoded for the phae (mr 40,950) and phac (mr 40,190) subunits of the pha synthase from t. pfennigii and exhibited high homology with the corresponding proteins of the c ... | 2000 | 10968631 |
| the role of structural intersubunit microheterogeneity in the regulation of the activity in hysteresis of ribulose 1, 5-bisphosphate carboxylase/oxygenase. | many enzymes are composed of subunits with the identical primary structure. it has been believed that the protein structure of these subunits is the same. ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) comprises eight large subunits with the identical amino acid sequence and eight small subunits. rotation of the side chains of the lysine residues, lys-21 and lys-305, in each of the eight large subunits in spinach rubisco in two ways produces microheterogeneity among the subunits. thes ... | 2000 | 11011141 |
| energy transfer and charge separation in the purple non-sulfur bacterium roseospirillum parvum. | the antenna reaction centre system of the recently described purple non-sulfur bacterium roseospirillum parvum strain 930i was studied with various spectroscopic techniques. the bacterium contains bacteriochlorophyll (bchl) a, 20% of which was esterified with tetrahydrogeranylgeraniol. in the near-infrared, the antenna showed absorption bands at 805 and 909 nm (929 nm at 6 k). fluorescence bands were located at 925 and 954 nm, at 300 and 6 k, respectively. fluorescence excitation spectra and tim ... | 2000 | 11106774 |
| pha synthase from chromatium vinosum: cysteine 149 is involved in covalent catalysis. | polyhydroxyalkanoate synthase (pha) from chromatium vinosum catalyzes the conversion of 3-hydroxybutyryl-coa (hb-coa) to polyhydroxybutyrate (phb) and coa. the synthase is composed of a approximately 1:1 mixture of two subunits, phac and phae. size-exclusion chromatography indicates that in solution phac and phae exist as large molecular weight aggregates. the holo-enzyme, phaec, has a specific activity of 150 units/mg. each subunit was cloned, expressed, and purified as a (his)6-tagged construc ... | 1999 | 9888824 |
| carbon monoxide and cyanide as intrinsic ligands to iron in the active site of [nife]-hydrogenases. nife(cn)2co, biology's way to activate h2. | infrared-spectroscopic studies on the [nife]-hydrogenase of chromatium vinosum-enriched in 15n or 13c, as well as chemical analyses, show that this enzyme contains three non-exchangeable, intrinsic, diatomic molecules as ligands to the active site, one carbon monoxide molecule and two cyanide groups. the results form an explanation for the three non-protein ligands to iron detected in the crystal structure of the desulfovibrio gigas hydrogenase (volbeda, a., garcin, e., piras, c., de lacey, a. i ... | 1999 | 9920874 |
| taxon-specific content of oligonucleotide triplets in 16s rrnas of anoxygenic phototrophic and nitrifying bacteria. | theoretical evaluation of the content of oligonucleotide triplets aaa, ccc, and uau in 16s rrnas of anoxygenic phototrophic bacteria (genera chlorobium; chloroflexus; chromatium: rhodopseudomonas) and nitrifying bacteria (genera nitrosococcus, nitrosomonas, nitrosolobus, nitrosovibrio, nitrospira, nitrospina, nitrobacter) showed that the number of the aaa, ccc or uau triplets in 16s rrnas specifically corresponds to the genus and species of bacteria. the ratio of aaa and ccc triplet numbers in t ... | 1999 | 10049622 |
| diversity of dissimilatory bisulfite reductase genes of bacteria associated with the deep-sea hydrothermal vent polychaete annelid alvinella pompejana. | a unique community of bacteria colonizes the dorsal integument of the polychaete annelid alvinella pompejana, which inhabits the high-temperature environments of active deep-sea hydrothermal vents along the east pacific rise. the composition of this bacterial community was characterized in previous studies by using a 16s rrna gene clone library and in situ hybridization with oligonucleotide probes. in the present study, a pair of pcr primers (p94-f and p93-r) were used to amplify a segment of th ... | 1999 | 10049872 |
| in situ analysis of phototrophic sulfur bacteria in the chemocline of meromictic lake cadagno (switzerland). | comparative sequence analysis of a 16s rrna gene clone library from the chemocline of the meromictic lake cadagno (switzerland) revealed the presence of a diverse number of phototrophic sulfur bacteria. sequences resembled those of rrna of type strains chromatium okenii dsm169 and amoebobacter purpureus dsm4197, as well as those of four bacteria forming a tight cluster with a. purpureus dsm4197 and lamprocystis roseopersicina dsm229. in situ hybridization with fluorescent (cy3 labeled) oligonucl ... | 1999 | 10049902 |
| pre-steady-state kinetics of the reactions of [nife]-hydrogenase from chromatium vinosum with h2 and co. | results are presented of the first rapid-mixing/rapid-freezing studies with a [nife]-hydrogenase. the enzyme from chromatium vinosum was used. in particular the reactions of active enzyme with h2 and co were monitored. the conversion from fully reduced, active hydrogenase (nia-sr state) to the nia-c* state was completed in less than 8 ms, a rate consistent with the h2-evolution activity of the enzyme. the reaction of co with fully reduced enzyme was followed from 8 to 200 ms. the nia-sr state di ... | 1999 | 10092843 |
| phylogeny and diversity of achromatium oxaliferum. | achromatium oxaliferum was first described in 1893 by schewiakoff as an unusually large bacterium living in freshwater sediments. up to now no pure culture is available. physical enrichments of achromatia collected from the acidic lake fuchskuhle, which houses a peculiar, smaller variety, and the neutral lake stechlin were investigated by the cultivation-independent rrna approach. pcr in combination with cloning and sequencing was used for the retrieval of 24 partial and 4 nearly full-length 16s ... | 1999 | 10188276 |
| structural and dynamical properties of a partially unfolded fe4s4 protein: role of the cofactor in protein folding. | heteronuclear multidimensional nmr spectroscopy was used to investigate in detail the structural and dynamical properties of a partially unfolded intermediate of the reduced high-potential iron-sulfur protein (hipip) from chromatium vinosum present in 4 m guanidinium chloride solution. after an extensive assignment of 15n and 1h resonances, noe data, proton longitudinal relaxation times, and 3jhnhalpha coupling constants as well as 15n relaxation parameters (t1, t2, t1rho, and 1h-15n noe) were o ... | 1999 | 10200154 |
| kinetics of photoacclimation in cultures of chromatium vinosum dsm 185 during shifts in light irradiance. | continuous cultures of chromatium vinosum dsm 185 were shifted from a high to a low irradiance (67 to 4 microe m(-2) s(-1)) and vice versa (4 to 67 microe m(-2) s(-1)). the kinetics of photoacclimation of the cultures were analysed during these transitions until steady state was reached. when irradiance was shifted from 4 to 67 microe m(-2) s(-1), bacteriochlorophyll synthesis halted for 4 h. during this period, pigments were progressively diluted in the newly formed biomass, resulting in a lowe ... | 1999 | 10220162 |
| unusual nmr, epr, and mössbauer properties of chromatium vinosum 2[4fe-4s] ferredoxin. | the ferredoxin from chromatium vinosum (cvfd) exhibits sequence and structure peculiarities. its two fe4s4(scys)4 clusters have unusually low potential transitions that have been unambiguously assigned here through nmr, epr, and mössbauer spectroscopy in combination with site-directed mutagenesis. the [4fe-4s]2+/1+ cluster (cluster ii) whose coordination sphere includes a two-turn loop between cysteines 40 and 49 was reduced by dithionite with an e degrees ' of -460 mv. its s = 1/2 epr signal wa ... | 1999 | 10320364 |
| mad structure of pseudomonas nautica dimeric cytochrome c552 mimicks the c4 dihemic cytochrome domain association. | the monohemic cytochrome c552from pseudomonas nautica (c552-pn) is thought to be the electron donor to cytochrome cd1, the so-called nitrite reductase (nir). it shows as high levels of activity and affinity for the p. nautica nir (nir-pn), as the pseudomonas aeruginosa enzyme (nir-pa). since cytochrome c552is by far the most abundant electron carrier in the periplasm, it is probably involved in numerous other reactions. its sequence is related to that of the c type cytochromes, but resembles tha ... | 1999 | 10369779 |
| uphill energy transfer in lh2-containing purple bacteria at room temperature | uphill energy transfer in the lh2-containing purple bacteria rhodopseudomonas acidophila, rhodopseudomonas palustris, rhodobacter sphaeroides, chromatium vinosum and chromatium purpuratum was studied by stationary fluorescence spectroscopy at room temperature upon selective excitation of the b800 pigments of lh2 and the b880 pigments of lh1 at 803 nm and 900 nm, respectively. the resulting fluorescence spectra differed significantly at wavelengths shorter than the fluorescence maximum but agreed ... | 1999 | 10393258 |
| catalytic electron transport in chromatium vinosum [nife]-hydrogenase: application of voltammetry in detecting redox-active centers and establishing that hydrogen oxidation is very fast even at potentials close to the reversible h+/h2 value. | the nickel-iron hydrogenase from chromatium vinosum adsorbs at a pyrolytic graphite edge-plane (pge) electrode and catalyzes rapid interconversion of h(+)((aq)) and h(2) at potentials expected for the half-cell reaction 2h(+) right arrow over left arrow h(2), i.e., without the need for overpotentials. the voltammetry mirrors characteristics determined by conventional methods, while affording the capabilities for exquisite control and measurement of potential-dependent activities and substrate-pr ... | 1999 | 10413472 |
| investigation of the role of a surface patch in the self-association of chromatium vinosum high potential iron-sulfur protein. | the role of a flattened, relatively hydrophobic surface patch in the self-association of chromatium vinosum hipip was assessed by substituting phenylalanine 48 with lysine. the reduction potential of the f48k variant was 26 mv higher than that of the wild-type (wt) recombinant (rc) hipip, consistent with the introduction of a positive charge close to the cluster. nuclear magnetic resonance spectroscopy (nmr) revealed that the electronic structure of the oxidized cluster in these two proteins is ... | 1999 | 10446369 |
| amino acid sequences of two high-potential iron-sulfur proteins (hipips) from the moderately halophilic purple phototrophic bacterium, rhodospirillum salinarum. | the amino acid sequences of two very different high-potential iron-sulfur protein (hipip) isozymes have been determined from the moderately halophilic purple phototrophic bacterium, rhodospirillum salinarum. iso-1 hipip, which is monomeric and contains 57 amino acid residues, is most similar to the thiobacillus ferrooxidans iron-oxidizing enzyme (45% identity and a 6-residue deletion). on the other hand, iso-2 hipip, which is isolated as an oligomer, contains a peptide chain with 54 amino acid r ... | 1999 | 10462450 |
| ab initio solution and refinement of two high-potential iron protein structures at atomic resolution. | the crystal structure of the reduced high-potential iron protein (hipip) from chromatium vinosum has been redetermined in a new orthorhombic crystal modification, and the structure of its h42q mutant has been determined in orthorhombic (h42q-1) and cubic (h42q-2) modifications. the first two were solved by ab initio direct methods using data collected to atomic resolution (1.20 and 0. 93 a, respectively). the recombinant wild type (rc-wt) with two hipip molecules in the asymmetric unit has 1264 ... | 1999 | 10531472 |
| an unusual arrangement of pur and lpx genes in the photosynthetic purple sulfur bacterium allochromatium vinosum. | the nucleotide sequence of a 1634 bp dna fragment from the photosynthetic purple sulfur bacterium allochromatium vinosum contains one complete and two partial open reading frames. sequence comparisons to genes from other organisms suggest that this a. vinosum dna fragment contains, starting from the 5' end, the following: (1) 234 bp at the 3' end of the a. vinosum purh gene, coding for 78 amino acids at the c-terminus of the bi-functional 5'-phosphoribosyl-5-aminoimidazole-4-carboxamide formyltr ... | 1999 | 10532315 |
| orientation-selected endor of the active center in chromatium vinosum [nife] hydrogenase in the oxidized "ready" state. | electron nuclear double resonance (endor) was applied to study the active site of the oxidized "ready" state, ni(r), in the [nife] hydrogenase of chromatium vinosum. the magnetic field dependence of the epr was used to select specific subsets of molecules contributing to the endor response by stepping through the epr envelope. three hyperfine couplings could be clearly followed over the complete field range. two protons, h1 and h2, display a very similar large isotropic coupling of 12.5 and 12.6 ... | 1999 | 10555572 |
| certain species of the proteobacteria possess unusual bacteriochlorophyll a environments in their light-harvesting proteins. | in this work, we have examined, using fourier-transform raman (ft-r) spectroscopy, the bacteriochlorophyll a (bchl a) binding sites in light-harvesting (lh) antennae from different species of the proteobacteria that exhibit unusal absorption properties. while the lh1 complexes from erythromicrobium (e.) ramosum (rc-b871) and rhodospirillum centenum (b875) present classic ft-r spectra in the carbonyl high-frequency region, we show that in the blue-shifted lh1 complex, absorbing at 856 nm, from ro ... | 1999 | 10604286 |
| experimental evidence for the role of buried polar groups in determining the reduction potential of metalloproteins: the s79p variant of chromatium vinosum hipip. | the amide group between residues 78 and 79 of chromatium vinosum high-potential iron-sulfur protein (hipip) is in close proximity to the fe4s4 cluster of this protein and interacts via a hydrogen bond with s gamma of cys77, one of the cluster ligands. the reduction potential of the s79p variant was 104 +/- 3 mv lower than that of the recombinant wild-type (rcwt) hipip (5 mm phosphate, 100 mm nacl, ph 7, 293 k), principally due to a decrease in the enthalpic term which favors the reduction of the ... | 1999 | 10631600 |
| [light-dependent incorporation of selenite into selenocysteine by isolated chromatophore of chromatium vinosum]. | illiminated intact chromatophore of chromatium vinosum in the presence of o-acetylserine(oas) catalysed incorporation of seo3(2-) into selenocysteine at rate of 359 nmol.mgbchl-1.h-1. sonicated chromatophore catalysed seo3(2-) incorporation at 1.1% of the rate of intact chromatophore. addition of gsh and nadph increased the rate to 88.3% of intact rate, but seo3(2-) incorporation under these conditions was essentially light dependent. the purified gsh reductase from chromatium vinosum in the pre ... | 1999 | 12555543 |
| discovery of a novel ferredoxin from azotobacter vinelandii containing two [4fe-4s] clusters with widely differing and very negative reduction potentials. | ferredoxins that contain 2[4fe-4s]2+/+ clusters can be divided into two classes. the "clostridial-type" ferredoxins have two cys-xaa-xaa-cys-xaa-xaa-cys-xaa-xaa-xaa-cys-pro motifs. the "chromatium-type" ferredoxins have one motif of that type and one more unusual cys-xaa-xaa-cys-xaa7-9-cys-xaa-xaa-xaa-cys-pro motif. here we report the purification of a novel ferredoxin (fdiii) from azotobacter vinelandii which brings to 12 the number of small [fe-s] proteins that have now been reported from this ... | 1998 | 9488675 |
| the cytochrome subunit structure in the photosynthetic reaction center of chromatium minutissimum. | gel-electrophoretic assay revealed that the photosynthetic reaction center (rc) of chromatium minutissimum, in contrast to the well-known rc rhodopseudomonas viridis, consists of five rather than four subunits with molecular masses of 37, 34, 25, 19, and 17 kda. the 37- and 19-kda subunits are stained with tetramethylbenzidine for the cytochrome c hemes. absorption spectra show that the concentration of reduced cytochromes in the c. minutissimum rc poised at redox potential of -150 mv (fully red ... | 1998 | 9490013 |
| phylogenetic position of an obligately chemoautotrophic, marine hydrogen-oxidizing bacterium, hydrogenovibrio marinus, on the basis of 16s rrna gene sequences and two form i rubisco gene sequences. | two form ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) genes from the obligately autotrophic, marine hydrogen oxidizer hydrogenovibrio marinus were sequenced. the deduced amino acid sequences of both rubiscos revealed that they are similar to those of sulfur oxidizers (thiobacillus) and a purple sulfur bacterium (chromatium vinosum). according to the 16s rrna gene sequences, h. marinus is also affiliated with these microorganisms, members of thiomicrospira being the closest relatives ... | 1998 | 9531639 |
| chaperonin 60(14) and co-chaperonin 10(7) from chromatium vinosum. | 1998 | 9534158 | |
| molecular genetic evidence for extracytoplasmic localization of sulfur globules in chromatium vinosum. | purple sulfur bacteria store sulfur as intracellular globules enclosed by a protein envelope. we cloned the genes sgpa, sgpb, and sgpc, which encode the three different proteins that constitute the sulfur globule envelope of chromatium vinosum d (dsmz 180(t)). southern hybridization analyses and nucleotide sequencing showed that these three genes are not clustered in the same operon. all three genes are preceded by sequences resembling sigma70-dependent promoters, and hairpin structures typical ... | 1998 | 9560425 |
| in vitro biosynthesis of poly(3-hydroxybutyric acid) by using purified poly(hydroxyalkanoic acid) synthase of chromatium vinosum. | purified recombinant poly(hydroxyalkanoic acid) (pha) synthase from chromatium vinosum (phaeccv) was used to examine in vitro the specific synthase activity, turnover of r-(-)-3-hydroxybutyryl coenzyme a (3hb-coa) and poly(3-hydroxybutyric acid) formation under various conditions. the 3hb-coa consumption was terminated by a reaction-dependent inactivation of the pha synthase. salts (mgcl2, cacl2, nacl), proteins (bovine serum albumin, lysozyme, phasine) or detergent (tween 20) increased the 3hb- ... | 1998 | 9581289 |
| the two [4fe-4s] clusters in chromatium vinosum ferredoxin have largely different reduction potentials. structural origin and functional consequences. | the 2[4fe-4s] ferredoxin from chromatium vinosum arises as one prominent member of a recently defined family of proteins found in very diverse bacteria. the potentiometric circular dichroism titrations of the protein and of several molecular variants generated by site-directed mutagenesis have established that the reduction potentials of the two clusters differ widely by almost 200 mv. this large difference has been confirmed by electrochemical methods, and each redox transition has been assigne ... | 1998 | 9624123 |
| sulfide oxidation in the phototrophic sulfur bacterium chromatium vinosum. | sulfide oxidation in the phototrophic purple sulfur bacterium chromatium vinosum d (dsmz 180(t)) was studied by insertional inactivation of the fccab genes, which encode flavocytochrome c, a protein that exhibits sulfide dehydrogenase activity in vitro. flavocytochrome c is located in the periplasmic space as shown by a phoa fusion to the signal peptide of the hemoprotein subunit. the genotype of the flavocytochrome-c-deficient chr. vinosum strain fd1 was verified by southern hybridization and p ... | 1998 | 9639604 |
| evidence against the double-arginine motif as the only determinant for protein translocation by a novel sec-independent pathway in escherichia coli. | proteins which are synthesized with a signal peptide containing a 'double-arginine' motif may be translocated across the bacterial cytoplasmic membrane by a mechanism that is different from the known sec and signal recognition particle pathways. the function of the double-arginine motif as a determinant for this novel pathway was studied by expressions of gene constructs coding for the high potential iron-sulfur protein (hipip) from chromatium vinosum d in escherichia coli. when the protein was ... | 1998 | 9682482 |
| synechocystis sp. pcc6803 possesses a two-component polyhydroxyalkanoic acid synthase similar to that of anoxygenic purple sulfur bacteria. | during cultivation under storage conditions with bg11 medium containing acetate as a carbon source, synechocystis sp. pcc6803 accumulated poly(3-hydroxybutyrate) up to 10% (w/w) of the cell dry weight. our analysis of the complete synechocystis sp. pcc6803 genome sequence, which had recently become available, revealed that not only the open reading frame slr1830 (which was designated as phac) but also the open reading frame slr1829, which is located colinear and upstream of phac, most probably r ... | 1998 | 9683655 |
| sirohaem sulfite reductase and other proteins encoded by genes at the dsr locus of chromatium vinosum are involved in the oxidation of intracellular sulfur. | the sequence of the dsr gene region of the phototrophic sulfur bacterium chromatium vinosum d (dsmz 180) was determined to clarify the in vivo role of 'reverse' sirohaem sulfite reductase. the dsrab genes encoding dissimilatory sulfite reductase are part of a gene cluster, dsrabefhcmk, that encodes four small, soluble proteins (dsre, dsrf, dsrh and dsrc), a transmembrane protein (dsrm) with similarity to haem-b-binding polypeptides and a soluble protein (dsrk) resembling [4fe-4s]-cluster-contain ... | 1998 | 9695921 |