Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| cytochrome c(2) is not essential for photosynthetic growth of rhodopseudomonas capsulata. | the structural gene for cytochrome c(2) (cyca) of the photosynthetic bacterium rhodopseudomonas capsulata has been cloned, and the nucleotide and deduced polypeptide sequences have been determined. compared with the known amino acid sequence of the purified cytochrome c(2), the nucleotide sequence corresponding to the n-terminal part of the cyca gene product indicates the presence of a putative 21 amino acid signal sequence. thus, cytochrome c(2) may be synthesized as a precursor which is proces ... | 1986 | 16593675 |
| femtosecond spectroscopy of excitation energy transfer and initial charge separation in the reaction center of the photosynthetic bacterium rhodopseudomonas viridis. | reaction centers from the photosynthetic bacterium rhodopseudomonas viridis have been excited within the near-infrared absorption bands of the dimeric primary donor (p), of the "accessory" bacteriochlorophylls (b), and of the bacteriopheophytins (h) by using laser pulses of 150-fsec duration. the transfer of excitation energy between h, b, and p occurs in slightly less than 100 fsec and leads to the ultrafast formation of an excited state of p. this state is characterized by a broad absorption s ... | 1986 | 16593728 |
| primary photochemistry of iron-depleted and zinc-reconstituted reaction centers from rhodopseudomonas sphaeroides. | the primary photochemistry of fe-depleted and zn-reconstituted reaction centers from rhodopseudomonas sphaeroides r-26.1 was studied by transient absorption spectroscopy and compared with native, fe(2+)-containing reaction centers. excitation of metal-free reaction centers with 30-ps flashes produced the initial charge-separated state p(+)i(-) (p(+)bph(-), where p is the primary donor and bph is bacteriopheophytin) with a yield and visible/near-infrared absorption difference spectrum indistingui ... | 1986 | 16593750 |
| isotope effect on electron transfer in reaction centers from rhodopseudomonas sphaeroides. | previous endor studies on reaction centers from rhodopseudomonas sphaeroides have shown the presence of two hydrogen-bonded protons associated with the primary, ubiquinone, acceptor q(a). these protons exchange with deuterons from solvent (2)h(2)o. the effect of this deuterium substitution on the charge-recombination kinetics (bchl)(2) (+)q(a) (-) --> (bchl)(2)q(a) has been studied with a sensitive kinetic difference technique. the electron-transfer rate was found to increase with deuterium exch ... | 1986 | 16593776 |
| role of charge-transfer states in bacterial photosynthesis. | photon echo, photon-echo excitation, and "hole-burning" data recorded in the 800-990 nm region of rhodobacter sphaeroides r26 and rhodopseudomonas viridis reaction centers are reported. the primary process in these reaction centers, following excitation, was found to occur in approximately 25 fsec; the long-wavelength band of the primary electron donor (p) was largely homogeneously broadened. in accordance with our previous explanation of hole-burning and photon-echo measurements on rb. sphaeroi ... | 1986 | 16593787 |
| nucleotide sequence and transcription of the fbc operon from rhodopseudomonas sphaeroides. evaluation of the deduced amino acid sequences of the fes protein, cytochrome b and cytochrome c1. | the fbc operon from rhodopseudomonas sphaeroides encodes the three redox carriers of the ubiquinol-cytochrome-c reductase (b/c1 complex): fes protein, cytochrome b and cytochrome c1 [gabellini, n. et al. (1985) embo j.2, 549-553]. the nucleotide sequence of 3874 bp of cloned r. sphaeroides chromosomal dna, including the three structural genes fbcf, fbcb and fbcc has been determined. the reading frames of the fbc genes could be identified readily since the encoded amino acid sequences are highly ... | 1986 | 3004982 |
| electron-transfer processes in photosynthetic reaction centres. | 1986 | 3007234 | |
| purification and properties of a soluble inorganic pyrophosphatase from rhodopseudomonas palustris. | a soluble inorganic pyrophosphatase from photolithoautotrophically grown rhodopseudomonas palustris was purified to a state of apparent homogeneity applying high resolving liquid chromatography steps. values of 65 500 and 64 500 were calculated for the relative molecular mass under non-dissociating conditions employing gel filtration and high-performance liquid chromatography, respectively. dissociation sodium dodecyl sulfate gel electrophoresis resulted in a value of 32 000, indicating that the ... | 1986 | 3008782 |
| kinetic characterization and partial purification of the membrane-bound inorganic pyrophosphatase from rhodopseudomonas palustris. | a membrane-bound inorganic pyrophosphatase from rhodopseudomonas palustris has been studied by kinetic analysis. the enzymatic activity was stimulated by mg2+, and the (mg-ppi) complex is regarded to be the functional substrate. free mg2+ revealed a significant influence on the membrane-bound ppiase activity. kinetic data were determined at various fixed concentrations of free mg2+. mg2+ is proposed to act as an activator in two ways. it may interact with the enzyme directly, and may combine wit ... | 1986 | 3008783 |
| the epr spectra of the cytochrome b-c1 complex of rhodopseudomonas sphaeroides. | the purified cytochrome b-c1 complex of rhodopseudomonas sphaeroides has two b cytochromes distinguishable by optical, thermodynamic and electron paramagnetic resonance criteria (gz values are approximately equal to 3.75 and approximately equal to 3.4). epr features typical of a rieske iron sulfur cluster (g values of 2.03 1.90 and 1.81) and a c1 type cytochrome (g approximately equal to 3.4) were also observed. the b and c1 cytochromes were individually purified from the complex. the cytochrome ... | 1986 | 3010986 |
| iron-depleted reaction centers from rhodopseudomonas sphaeroides r-26.1: characterization and reconstitution with fe2+, mn2+, co2+, ni2+, cu2+, and zn2+. | reaction centers (rcs) from the photosynthetic bacterium rhodopseudomonas sphaeroides r-26.1 were depleted of fe by a simple procedure involving reversible dissociation of the h subunit. the resulting intact fe-depleted rcs contained 0.1-0.2 fe per rc as determined from atomic absorption and electron paramagnetic resonance (epr) spectroscopy. fe-depleted rcs that have no metal ion occupying the fe site differed from native rcs in the following respects: (1) the rate of electron transfer from qa- ... | 1986 | 3011083 |
| energy and signal transduction by transmembrane protein complexes. | 1986 | 3012365 | |
| cloning of dna fragments carrying hydrogenase genes of rhodopseudomonas capsulata. | a cosmid library of rhodopseudomonas capsulata dna was constructed in escherichia coli hb101 using the broad-host-range cosmid vector plafr1. more than ninety per cent of the clones in the bank contained cosmids with dna inserts averaging 20 kilobase pairs in length. mutants deficient in uptake hydrogenase (hup-) were obtained from r. capsulata strain b10 by ethylmethylsulfonate (ems) mutagenesis. the content of hydrogenase protein in hup- mutant cells was tested by rocket immunoelectrophoresis. ... | 1986 | 3015242 |
| anaerobic regulation of nitrogen-fixation genes in rhodopseudomonas capsulata. | a rhodopseudomonas capsulata nifh::lacz gene fusion was used to isolate constitutive mutants of r. capsulata, unable to repress nif gene transcription anaerobically with every fixed-nitrogen source tested. when these nifc strains were grown aerobically, nif gene transcription was repressed. these results indicate that the regulation of nif gene transcription by fixed nitrogen is different from the regulation by oxygen. under anaerobic conditions, nif gene transcription in both r. capsulata and k ... | 1986 | 3018747 |
| demonstration of a collisional interaction of ubiquinol with the ubiquinol-cytochrome c2 oxidoreductase complex in chromatophores from rhodobacter sphaeroides. | ubiquinone-10 can be extracted from lyophilized chromatophores of rhodobacter sphaeroides (previously called rhodopseudomonas sphaeroides) without significant losses in other components of the electron-transfer chain or irreversible damages in the membrane structure. the pool of ubiquinone can be restored with exogenous uq-10 to sizes larger than the ones in unextracted membranes. the decrease in the pool size has marked effects on the kinetics of reduction of cytochrome b-561 induced by a singl ... | 1986 | 3019393 |
| development of a gene cloning system for the hydrogen-producing marine photosynthetic bacterium rhodopseudomonas sp. | seventy-six strains of marine photosynthetic bacteria were analyzed by agarose gel electrophoresis for plasmid dna content. among these strains, 12 carried two to four different plasmids with sizes ranging from 3.1 to 11.0 megadaltons. the marine photosynthetic bacterium rhodopseudomonas sp. nkpb002106 had two plasmids, prd06s and prd06l. the smaller plasmid, prd06s, had a molecular weight of 3.8 megadaltons and was cut at a single site by restriction endonucleases sali, smai, psti, xhoi, and bg ... | 1986 | 3020006 |
| the gene crti mediates the conversion of phytoene into colored carotenoids in rhodopseudomonas capsulata. | carotenoids are membrane pigments present in all photosynthetic organisms, providing essential photoprotective functions. the first carotenoid formed in the pathway is phytoene, a colorless compound which is then converted into colored carotenoids by a series of dehydrogenation reactions. in the photosynthetic bacterium rhodopseudomonas capsulata mutations that affect carotenoid biosynthesis before colored carotenoids are formed have a "blue-green" phenotype as opposed to the "red" of wild type ... | 1986 | 3020015 |
| immunological comparison of the b and c1 cytochromes from bovine heart mitochondria and the photosynthetic bacterium rhodopseudomonas sphaeroides r-26. | antibodies against cytochromes b and c1 of bovine heart mitochondria and the photosynthetic bacterium, rhodopseudomonas sphaeroides r-26, were raised in rabbits. the purified antibodies showed high titers against their respective antigens in enzyme-linked immunosorbent assays. less than 15% cross-reactivity between the mitochondrial and bacterial cytochromes was detected. although antibodies against mitochondrial cytochrome b did not inhibit the mitochondrial cytochrome b-c1 complex, a 70% inhib ... | 1986 | 3021746 |
| structural homology of reaction centers from rhodopseudomonas sphaeroides and rhodopseudomonas viridis as determined by x-ray diffraction. | crystals of the reaction center (rc) from rhodopseudomonas sphaeroides with the space group p2(1)2(1)2(1), have been studied by x-ray diffraction. the patterson search (molecular replacement) technique was used to analyze the data, with the structure of the reaction center from rhodopseudomonas viridis as a model system. a preliminary electron density map of the reaction center from r. sphaeroides has been obtained. comparison of the structure of the rc from r. sphaeroides with that from r. viri ... | 1986 | 3022298 |
| the phosphoenolpyruvate-dependent fructose-specific phosphotransferase system in rhodopseudomonas sphaeroides. distribution of eiifru over the membranes of phototrophically grown rps. sphaeroides. | the distribution of the fructose carrier over the membranes of rhodopseudomonas sphaeroides was studied in cells grown under light saturation and light limitation. three types of membranes were isolated after disruption of the cells in a french press. all three types were present in the cells grown either under the high or low light intensity, but they were present in different quantities. the cytoplasmic membrane could be separated from the photosynthetic membranes by sephacryl s-1000 chromatog ... | 1986 | 3023083 |
| isolation of the rhodopseudomonas sphaeroides form i ribulose 1,5-bisphosphate carboxylase/oxygenase large and small subunit genes and expression of the active hexadecameric enzyme in escherichia coli. | a library of cloned rhodopseudomonas sphaeroides dna was screened by colony hybridization for form i ribulose 1,5-bisphosphate carboxylase/oxygenase (rubpc/o) sequences using heterologous rubpc/o probes. a recombinant plasmid was identified that hybridized to both the anacystis nidulans and the r. sphaeroides form ii rubpc/o genes. subcloning of a hybridizing 4-kb smai fragment allowed expression of active enzyme in escherichia coli that was identical to form i rubpc/o based on polyacrylamide ge ... | 1986 | 3023189 |
| purification and properties of an acetate kinase from rhodopseudomonas palustris. | an acetate kinase from the photolithoautotrophically grown purple bacterium rhodopseudomonas palustris was purified to apparent homogeneity by use of high resolving liquid chromatography steps. the monomeric enzyme was characterized by a relative molecular mass of 46,500 and an isoelectric point of 4.9. there was an absolute requirement for divalent metal ions in the enzymatic reaction. mg2+ and mn2+ were the most activating cations. the acetate kinase used pyrimidine and purine nucleotides almo ... | 1986 | 3024667 |
| independent regulation of synthesis of form i and form ii ribulose bisphosphate carboxylase-oxygenase in rhodopseudomonas sphaeroides. | ribulose 1,5-bisphosphate carboxylase-oxygenase (rubpc-o) activity was greatly enhanced when rhodopseudomonas sphaeroides was grown in a mineral salts medium supplied with 1.5% co2 in hydrogen. analysis of cell extracts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that cells growing on 1.5% co2 in h2 specifically accumulated rubpc-o polypeptides. quantitative immunological determinations revealed that accumulation of form i and form ii rubpc-o closely correlates with th ... | 1986 | 3080410 |
| purple-bacterial light-harvesting complexes. | 1986 | 3082693 | |
| the metabolism of carbaryl by three bacterial isolates, pseudomonas spp. (ncib 12042 & 12043) and rhodococcus sp. (ncib 12038) from garden soil. | at an alkaline ph and in aqueous solution, carbaryl hydrolyses to form 1-naphthol, methylamine and carbon dioxide, but it is much more stable at an acid ph. two bacterial isolated from garden soil, pseudomonas sp. (ncib 12042) and rhodococcus sp. (ncib 12038), could grow on carbaryl as sole carbon and nitrogen source at ph 6.8 but failed to metabolize carbaryl rapidly. both could use 1-naphthol as sole carbon source and ncib 12042 metabolized 1-naphthol via salicylic acid which induced higher ex ... | 1986 | 3086270 |
| nanosecond fluorescence from chromatophores of rhodopseudomonas sphaeroides and rhodospirillum rubrum. | single-photon counting techniques were used to measure the fluorescence decay from rhodopseudomonas sphaeroides and rhodospirillum rubrum chromatophores after excitation with a 25-ps, 600-nm laser pulse. electron transfer was blocked beyond the initial radical-pair state (pf) by chemical reduction of the quinone that serves as the next electron acceptor. under these conditions, the fluorescence decays with multiphasic kinetics and at least three exponential decay components are required to descr ... | 1986 | 3087422 |
| some important concepts in the current theories of electron transfer in biological systems. | the main concepts pertinent to the current theories of electron transfer in biological systems are briefly presented. the different models used to evaluate the purely electronic factors of the transfer are reviewed. | 1986 | 3089326 |
| expression of cellulase genes in rhodobacter capsulatus by use of plasmid expression vectors. | broad-host-range plasmid vectors were constructed for expression of heterologous genes in the photosynthetic bacterium rhodobacter capsulatus. these plasmids utilize an rk2-derived replicon for maintenance and conjugative transfer and the r. capsulatus rxca promoter to obtain transcription of genes within appropriately positioned dna fragments. the expression vectors were used to obtain synthesis of endoglucanase and exoglucanase in r. capsulatus from cellulase genes present on exogenously deriv ... | 1986 | 3090019 |
| organization of the genes for nitrogen fixation in photosynthetic bacteria and cyanobacteria. | 1986 | 3096194 | |
| molecular cloning and sequence of the b880 holochrome gene from rhodospirillum rubrum. | restriction fragments of genomic rhodospirillum rubrum dna were selected according to size by electrophoresis followed by hybridization with [32p]mrna encoding the two b880 holochrome polypeptides. the fragments were cloned into escherchia coli c600 with plasmid pbr327 as a vector. the clones were selected by colony hybridization with 32p-holochrome-mrna and counterselected by hybridization with rs. rubrum ribosomal rna, a minor contaminant of the mrna preparation. chimeric plasmid prr22 was sho ... | 1986 | 3001063 |
| discrete catalytic sites for quinone in the ubiquinol-cytochrome c2 oxidoreductase of rhodopseudomonas capsulata. evidence from a mutant defective in ubiquinol oxidation. | a non-photosynthetic mutant (ps-) of rhodopseudomonas capsulata, designated r126, was analyzed for a defect in the cyclic electron transfer system. compared to a ps+ strain mr126, the mutant was shown to have a full complement of electron transfer components (reaction centers, ubiquinone-10, cytochromes b, c1, and c2, the rieske 2-iron, 2-sulfur (rieske fes) center, and the antimycin-sensitive semiquinone). functionally, mutant r126 failed to catalyze complete cytochrome c1 + c2 re-reduction or ... | 1986 | 3001072 |
| purification and properties of acyl coenzyme a thioesterase ii from rhodopseudomonas sphaeroides. | a high molecular weight acyl coenzyme a (acyl-coa) thioesterase, designated thioesterase ii, has been purified 5300-fold from photoheterotrophically grown cells of rhodopseudomonas sphaeroides. in contrast to r. sphaeroides acyl-coa thioesterase i [boyce, s.g., & lueking, d.r. (1984) biochemistry 23, 141-147], thioesterase ii has a native molecular mass (mr) of 120,000, is capable of hydrolyzing saturated and unsaturated acyl-coa substrates with acyl chain lengths ranging from c4 to c18, and is ... | 1986 | 2872920 |
| purification of the aa3-type cytochrome-c oxidase from rhodopseudomonas sphaeroides. | 1986 | 2856120 | |
| a conformational preference parameter to predict helices in integral membrane proteins. | assignments were made for helical regions in several integral membrane proteins using an algorithm devised to delineate the transmembrane helices in bacteriorhodopsin (eur. j. biochem. 182 (1982) 565-575). a new conformational preference parameter for membrane-buried helices was obtained. the use of this parameter to predict helices in membrane proteins is discussed. when applied to the l and m subunits of rhodopseudomonas sphaeroides, five helices were predicted, which is consistent with the th ... | 1986 | 2935194 |
| the stereospecificity of oxidation of alpha-[4r-2h]nadh by dehydrogenases. | the stereospecificity of the enzyme-dependent oxidation of alpha-[4r-2h]nadh has been determined for four dehydrogenases: two pro-r specific enzymes, pig heart malate dehydrogenase and yeast alcohol dehydrogenase; and two pro-s specific enzymes, rabbit muscle glycerol-3-phosphate dehydrogenase and rhodopseudomonas spheroides 3-hydroxybutyrate dehydrogenase. in all cases, an enzyme-dependent and substrate-specific oxidation to alpha-nad+ is observed with the stereochemistry of oxidation identical ... | 1986 | 2943736 |
| uptake of benzoate by rhodopseudomonas palustris grown anaerobically in light. | the uptake and anaerobic metabolism of benzoate were studied in short-term experiments with phototrophic cells of rhodopseudomonas palustris. cells that were preincubated and assayed anaerobically in the presence of 1 mm dithiothreitol accumulated [7-14c]benzoate at a rate of at least 0.5 nmol . min-1 . mg-1 of protein. cells that were preincubated aerobically, or anaerobically in the absence of a reducing agent or an electron donor such as succinate, took up benzoate at reduced rates. benzoate ... | 1986 | 3944059 |
| primary donor recovery kinetics in reaction centers from rhodopseudomonas viridis. the influence of ferricyanide as a rapid oxidant of the acceptor quinones. | in reaction centers from rhodopseudomonas viridis that contain a single quinone, the decay of the photo-oxidized primary donor, p+, was found to be biphasic when the bound, donor cytochromes were chemically oxidized by ferricyanide. the ratio of the two phases was dependent on ph with an apparent pk of 7.6. a fast phase, which dominated at high ph (t1/2 = 1 ms at ph 9.5), corresponded to the expected charge recombination of p+ and the primary acceptor qa-. a much slower phase dominated at low ph ... | 1986 | 3947620 |
| the phosphoenolpyruvate-dependent fructose-specific phosphotransferase system in rhodopseudomonas sphaeroides. eiifru possesses a zn2+-binding site and a dithiol/disulfide redox centre. | two interrelated sites have been detected on the fructose carrier in rhodopseudomonas sphaeroides: an activity-linked dithiol and a zn2+-binding site. binding of zn2+ brings eiifru into a new conformation that to some extent mimics the conformation of phosphorylated eiifru, an essential intermediate in the turnover of the enzyme. binding of zinc to eiifru or phosphorylating the enzyme protects it against trypsin inactivation relative to the dephosphorylated zinc-free enzyme. a dithiol is essenti ... | 1986 | 3948872 |
| plasmid pu29, a vehicle for mutagenesis of the photosynthetic puf operon in rhodopseudomonas capsulata. | plasmid pu21, which carries the reaction center and light-harvesting genes (puf operon) of rhodopseudomonas capsulata, has been redesigned by site-specific mutagenesis. five restriction sites have been removed and three unique restriction sites have been introduced into this 11,589-bp pbr322 derivative. the modifications divide the puf structural genes into four regions separated by five unique and nonmutagenic restriction sites. these four fragments have been subcloned into the m13-mp series of ... | 1986 | 3027725 |
| crystallization and preliminary x-ray diffraction study of ferrocytochrome c2 from rhodopseudomonas viridis. | crystals of ferrocytochrome c2 from a non-sulphur purple photosynthetic bacterium, rhodopseudomonas viridis, have been grown from ammonium sulphate solution at ph 8.5 by the sitting-drop vapour-diffusion procedure. the crystals belong to the trigonal system, space group p3(1)21 (or its enantiomorph p3(2)21) with unit-cell dimensions of a = b = 75.8 a and c = 40.1 a, and diffract to at least 2.0 a resolution. assuming that an asymmetric unit contains one protein molecule (approx. 12,300 mr), the ... | 1986 | 3029389 |
| characterization by epr spectroscopy of cytochrome b-562 isolated from the cytochrome b-c1 complex of rhodopseudomonas sphaeroides r-26. | the epr spectra of cytochrome b-562 isolated from the cytochrome b-c1 complex of rhodopseudomonas sphaeroides were measured at liquid helium temperature. the purified cytochrome b-562 gives a high spin signal at g = 6.0. anaerobic titration of this signal confirmed the presence of two redox components with em = 40 and -110 mv at ph 7.5. these values are consistent with the published ones, em = 55 and -100 mv at ph 7.0, that were optically estimated for the same type of preparation (iba et al. (1 ... | 1986 | 3032916 |
| primary structure of the reaction center from rhodopseudomonas sphaeroides. | the reaction center is a pigment-protein complex that mediates the initial photochemical steps of photosynthesis. the amino-terminal sequences of the l, m, and h subunits and the nucleotide and derived amino acid sequences of the l and m structural genes from rhodopseudomonas sphaeroides have previously been determined. we report here the sequence of the h subunit, completing the primary structure determination of the reaction center from r. sphaeroides. the nucleotide sequence of the gene encod ... | 1986 | 3329732 |
| ferrochelatase from rhodopseudomonas sphaeroides: substrate specificity and role of sulfhydryl and arginyl residues. | purified ferrochelatase (protoheme ferrolyase; ec 4.99.1.1) from the bacterium rhodopseudomonas sphaeroides was examined to determine the roles of cationic and sulfhydryl residues in substrate binding. reaction of the enzyme sulfhydryl residues with n-ethylmaleimide or monobromobimane resulted in a rapid loss of enzyme activity. ferrous iron, but not porphyrin substrate, had a protective effect against inactivation by these two reagents. quantitation with 3h-labeled n-ethylmaleimide revealed tha ... | 1986 | 3484475 |
| the phosphoenolpyruvate-dependent fructose-specific phosphotransferase system in rhodopseudomonas sphaeroides. energetics of the phosphoryl group transfer from phosphoenolpyruvate to fructose. | energy coupling to fructose transport in rhodopseudomonas sphaeroides is achieved by phosphorylation of the membrane-spanning fructose-specific carrier protein, efruii. the phosphoryl group of phosphoenolpyruvate is transferred to efruii via the cytoplasmic component sf (soluble factor). the standard free enthalpy of hydrolysis of the two phosphorylated proteins has been estimated from isotope exchange measurements in chemical equilibrium. the delta g degrees for sf-p is -60.5 kj/mol. the standa ... | 1986 | 3484702 |
| labelling of chlorophylls and precursors by [2-14c]glycine and 2-[1-14c]oxoglutarate in rhodopseudomonas spheroides and zea mays. resolution of the c5 and shemin pathways of 5-aminolaevulinate biosynthesis by thin-layer radiochromatography. | the c-5 of 5-aminolaevulinate, a tetrapyrrole precursor which accumulates when inhibitory laevulinate is present, is derived from either the c-2 of glycine by the 5-aminolaevulinate-synthase-mediated shemin pathway or the c-1 of 2-oxoglutarate by the c5 pathway. thin-layer-radiochromatographic procedures are described for determining whether [2-14c]glycine or 2-[1-14c]oxoglutarate labelled the macrocycle of bacteriochlorophyll a, in addition to or rather than the methyl ester or phytyl ester moi ... | 1986 | 3485524 |
| a new membrane-bound b-type cytochrome, cytochrome b-558, from photosynthetically grown rhodopseudomonas sphaeroides. | a new membrane-bound b-type cytochrome, cytochrome b-558, was removed from chromatophore membranes of photosynthetically grown rhodopseudomonas sphaeroides strain r-26 by deoxycholate-cholate extraction. the cytochrome was purified by ammonium sulfate fractionation and ion-exchange chromatography. cytochrome b-558 had absorption maxima at 280 and 405 nm in the oxidized form, and at 558, 528, and 420 nm in the reduced form. it had a midpoint potential of--130 mv at ph 7.0. the minimal molecular w ... | 1986 | 3485957 |
| multiple-phase equilibration headspace analysis for the determination of n2o and n2 during bacterial denitrification. | a gas-handling manifold for the preparation, introduction and analysis by gas chromatography (gc) system of the gaseous products of denitrification is described. a procedure of multiple-phase equilibration is adopted which allows the quantitative determination of the total gas present in sample vials. assumptions of solubility coefficients are not required as these are determined during the analysis. the method is particularly suited to gases of appreciable solubilities as a significant proporti ... | 1986 | 3487992 |
| the phosphoenolpyruvate-dependent fructose-specific phosphotransferase system in rhodopseudomonas sphaeroides. evidence for a shift in the midpoint potential of the dithiol redox center during turnover of the carrier. | redox titrations of the fructose-specific carrier protein, efruii, in rhodopseudomonas sphaeroides show that only the reduced form of the enzyme is active. the oxidized form of the enzyme can still be phosphorylated but is unable to transfer the phosphoryl group to fructose. the redox properties of the enzyme change upon phosphorylation. the reduction rate of efruii is slower than that of efruii-p, whereas the opposite is true for the oxidation rate. consequently the midpoint potential of the re ... | 1986 | 3488904 |
| [rhodopseudomonas sphaeroides mutants defective in nitrogen fixation]. | mutants of phototrophic bacterium rhodopseudomonas sphaeroides deficient in nitrogen fixation and unable to utilize alanine, proline, arganine and glutamic acid as nitrogen sources have been obtained as a result of nitrosomethylurea mutagenesis. the majority of the nif-mutants have no nitrogenase activity and aminotransferase activity of glutamine synthetase during their growth in glutamine containing medium is sharply lowered. the specific activity of glutamate synthase and alanine dehydrogenas ... | 1986 | 3489487 |
| purification and characterization of bacterial ferrochelatase. | 1986 | 3702737 | |
| purification of 5-aminolevulinate synthase. | 1986 | 3702741 | |
| nucleotide sequences of 5s ribosomal rnas of protomonas extorquens, rhodopseudomonas palustris, rhodobacter capsulatus, and erythrobacter longus. | 1986 | 3714477 | |
| test for sulfolipid formation from [35s]sulfate as an aid to differentiate mycobacteria from rhodococci and nocardiae. | 1986 | 3747867 | |
| the nucleotide sequence of the 5 s rrna of rhodobacter capsulatus atcc 23782. | 1986 | 3786137 | |
| purification and characterization of a phosphotransacetylase from rhodopseudomonas palustris. | a phosphotransacetylase was purified to apparent homogeneity from photolithoautotrophically grown rhodopseudomonas palustris by liquid chromatography methods. a 400-fold increase in specific activity could be achieved. the enzyme was characterized by a relative molecular mass of 54,500, an isoelectric point of 6.3 and the absence of dissociable subunits. the enzyme appeared very labile at elevated temperatures or in diluted solutions. the stability could be increased distinctly in case sulfate o ... | 1986 | 3790263 |
| in vitro biosynthesis and membrane association of photosynthetic reaction center subunits from rhodopseudomonas sphaeroides. | the reaction center of rhodopseudomonas sphaeroides is an integral membrane protein complex responsible for primary photochemical charge separation in photosynthesis. we report the synthesis of two of the three subunits of the photosynthetic reaction center using a dna-directed in vitro transcription-translation system prepared from r. sphaeroides. the in vitro-synthesized polypeptides, as resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, had apparent mrs of 24,000 and 21,00 ... | 1986 | 3512531 |
| role of apparent membrane growth initiation sites during photosynthetic membrane development in synchronously dividing rhodopseudomonas sphaeroides. | sites of intracytoplasmic membrane growth and temporal relations in the assembly of photosynthetic units were examined in synchronously dividing rhodopseudomonas sphaeroides cells. after rate-zone sedimentation of cell-free extracts, apparent sites of initiation of intracytoplasmic membrane growth formed an upper pigmented band that sedimented more slowly than the intracytoplasmic membrane-derived chromatophore fraction. throughout the cell cycle, the levels of the peripheral b800-850 light-harv ... | 1986 | 3522542 |
| localization of the exposed n-terminal region of the b800-850 alpha and beta light-harvesting polypeptides on the cytoplasmic surface of rhodopseudomonas capsulata chromatophores. | proteinase k and trypsin were used to determine the orientation of the light-harvesting b800-850 alpha and beta polypeptides within the chromatophores (inside-out membrane vesicles) of the mutant strain y5 of rhodopseudomonas capsulata. with proteinase k 7 amino acid residues of the b800-850 alpha polypeptide were cleaved off up to position trp-7--thr-8 of the n terminus, and 11 residues were cleaved off up to position leu-11-ser-12 of the beta chain n terminus. the c termini of the b800-850 alp ... | 1986 | 3522557 |
| mapping of the triazine binding site to a highly conserved region of the qb-protein. | a number of herbicide classes, including the s-triazines and ureas (atrazine, diuron) inhibit photosynthetic electron transport via a direct interaction with the qb-protein. this protein, also known as the 32-kda protein or herbicide binding protein, is believed to bind the plastoquinone qb, which functions as the second stable electron acceptor at the reducing side of photosystem ii. the site of covalent attachment of the photoaffinity herbicide analog azido-[14c]atrazine to the qb-protein of s ... | 1986 | 3524461 |
| radical-pair energetics and decay mechanisms in reaction centers containing anthraquinones, naphthoquinones or benzoquinones in place of ubiquinone. | in reaction centers from rhodobacter sphaeroides (formerly called rhodopseudomonas sphaeroides), light causes an electron-transfer reaction that forms the radical pair state (p+i-, or pf) from the initial excited singlet state (p) of a bacteriochlorophyll dimer (p). subsequent electron transfer to a quinone (q) produces the state p+q-. back electron transfer can regenerate p from p+q-, giving rise to 'delayed' fluorescence that decays with approximately the same lifetime as p+q-. the free-energy ... | 1986 | 3524681 |
| methods for the determination of membrane potential in bioenergetic systems. | 1986 | 3526088 | |
| structure of rhodopseudomonas sphaeroides r-26 reaction center. | the molecular replacement method has been successfully used to provide a structure for the photosynthetic reaction center of rhodopseudomonas sphaeroides at 3.7 a resolution. atomic coordinates derived from the r. viridis reaction center were used in the search structure. the crystallographic r-factor is 0.39 for reflections between 8 and 3.7 a. validity of the resulting model is further suggested by the visualization of amino acid side chains not included in the r. viridis search structure, and ... | 1986 | 3527749 |
| [selective method of isolating mutants sensitive to ultraviolet radiation from a culture of rhodopseudomonas sphaeroides]. | the method of penicillin selection used after uv-irradiation (lambda = 254 nm) allows one to select uv-sensitive mutants (uvs-mutants) of the phototrophous bacterium rhodopseudomonas sphaeroides induced by nitrosomethylurea with an effectiveness greater by an order of magnitude. over 30% of the uvs-mutants obtained using this method had an elevated sensitivity not only to far-uv (f-uv, lambda = 254 nm) but also to near-uv (n-uv, lambda greater than 280 nm) uv-irradiation. no correlation was foun ... | 1986 | 3528771 |
| effect of uncoupler on assembly pathway for pigment-binding protein of bacterial photosynthetic membranes. | the uncoupler carbonylcyanide m-chlorophenylhydrazone (cccp) was used to investigate membrane protein assembly in the phototrophic bacterium rhodobacter capsulatus. as found for escherichia coli (t. date, g. zwizinsky, s. ludmerer, and w. wickner, proc. natl. acad. sci. 77:827-831, 1980) and mitochondrial proteins (n. nelson and g. schatz, proc. natl. acad. sci. usa 76:4365-4369, 1979), assembly across the bacterial photosynthetic membranes was sensitive to cccp. at uncoupler concentrations whic ... | 1986 | 3531166 |
| regulation of expression of genes for light-harvesting antenna proteins lh-i and lh-ii; reaction center polypeptides rc-l, rc-m, and rc-h; and enzymes of bacteriochlorophyll and carotenoid biosynthesis in rhodobacter capsulatus by light and oxygen. | rna levels were measured by blot hybridization to study the coordinate and differential expression of rhodobacter capsulatus genes for light-harvesting i antenna proteins lh-i and lh-ii; reaction center (rc) polypeptides l, m, and h; and bacteriochlorophyll and carotenoid biosynthesis in response to light and o2. the genes for lh-ii alpha and beta subunits only have one transcript, 0.5 kilobase (kb) long, whereas the genes for lh-i have two transcripts (0.5 and 2.6 kb). the small transcript (0.5 ... | 1986 | 3532117 |
| a dna fragment hybridizing to a nif probe in rhodobacter capsulatus is homologous to a 16s rrna gene. | we have sequenced the rhodobacter capsulatus nifh and nifd genes. the nifh gene, which codes for the dinitrogenase reductase protein, is 894 bp long and codes for a polypeptide of predicted mr 32,412. the nifd gene, which codes for the alpha subunit of dinitrogenase, is 1,500 bp long and codes for a protein of predicted mr 56,113. a 776-bp bglii-xhoi fragment containing only nif sequences was used as a hybridization probe against r. capsulatus genomic dna. two hindiii fragments, 11.8 kb and 4.7 ... | 1986 | 3557130 |
| the site of inhibition of the chloroplast electron-transport system by 2,3-dithiopropan-1-ol (bal). | bal (2,3-dithiopropan-1-ol) treatment of chloroplasts has previously been reported to induce a block in electron transport from water to nadp+ at a site preceding plastocyanin [belkin et al. (1980) biochim. biophys. acta 766, 563-569]. in the present work the block was further characterized. the following properties of bal treatment are described. inhibition of electron transport from water to lipophilic acceptors but not to silicomolybdate. inhibition of the slow, sigmoidal phase of chlorophyll ... | 1987 | 3569275 |
| purification and characterization of a catalase-peroxidase from the photosynthetic bacterium rhodopseudomonas capsulata. | catalase-peroxidase was isolated from aerobically grown rhodopseudomonas capsulata. the enzyme resembles typical catalases in some of its physicochemical properties. it has an apparent molecular weight of 236,000 and is composed of four identical subunits. it shows a typical high spin ferric heme spectrum with absorption maxima at 403 and 635 nm and shoulders at 503 and 535 nm. upon binding of cyanide, the enzyme is converted to the low spin state, as shown by the shift of the soret maximum to 4 ... | 1987 | 3571290 |
| biosynthesis of porphyrins in rhodopseudomonas palustris--vi. the effect of metals, thiols and other reagents on the activity of uroporphyrinogen decarboxylase. | the effect of several metals and reagents on the decarboxylation rate of uroporphyrinogen i by using a 16-fold purified preparation of uroporphyrinogen decarboxylase from rhodopseudomonas palustris, was studied. 1 mm hg2+ and cu2+ were strong inhibitors, 1 mm zn2+ and fe2+ under certain conditions and 1 mm fe3+ and cr3+ also inactivated the enzyme, but pb2+, cd2+ and al3+ did not. metals inhibition was reversed by 1 mm gsh or cysh. 0.1 mm dtnb and pcmb, 1 mm pyridoxal phosphate and 100 mm chlora ... | 1987 | 3595985 |
| porphyrin biosynthesis in rhodopseudomonas palustris--xii. delta-aminolevulinate synthetase switch-off/on regulation. | the high levels of delta-aminolevulinate synthetase (ala-s) in rhodopseudomonas palustris cells grown anaerobically in the light (ph) decrease to those found in cells grown aerobically in the dark (a), when the former cultures were vigorously oxygenated; simultaneously bacteriochlorophyll (bchl) synthesis abruptly halted leading to diminished steady-state specific bchl content. when flushing oxygen was interrupted, enzymic activity increased, whether chloramphenicol was present or not in the med ... | 1987 | 3595986 |
| kinetic measurements of electron transfer in coupled chromatophores from photosynthetic bacteria. a method of correction for the electrochromic effects. | a quantitative study of the kinetics of electron transfer under coupled conditions in photosynthetic bacteria has so far been prevented by overlap of the electrochromic signals of carotenoids and bacteriochlorophyll with the absorbance changes of cytochromes and reaction centers. in this paper a method is presented by which the electrochromic contribution at any wavelength can be calculated from the electrochromic signal recorded at 505 nm, using a set of empirically determined polynomial functi ... | 1987 | 3609307 |
| charge recombination from the p+qa- state in reaction centers from rhodopseudomonas viridis. | the rate of decay of the flash-oxidized primary electron donor, p+, from the state p+qa- was studied in reaction centers from rhodopseudomonas viridis, containing only the primary menaquinone electron acceptor (qa). at 295 k, in 100 mm nacl and in the presence of o-phenanthroline, the rate of recombination was 470 +/- 15 s-1 at ph 7 and 570 +/- 20 s-1 at ph 9. the rate at ambient temperatures varied somewhat with viscosity, ph and ionic strength. between 310 k and 275 k, the temperature dependen ... | 1987 | 3651444 |
| photochemical electron transfer reactions in the acceptor complex of reaction centers of rhodopseudomonas spheroides treated with sodium dodecyl sulfate. | we have compared some photochemical properties of the reaction-center complex of rhodopseudomonas spheroides (wild-type) treated with various amounts of either sodium dodecyl sulfate (sds) or dodecyl dimethylamine n-oxide. in the presence of the latter, the native structure and activity of the reaction center are preserved even at high concentrations of detergent. in contrast, sds denatures the protein. it does this by a cooperative process, as shown by the sigmoidal relationship between primary ... | 1987 | 3297697 |
| structure of the reaction center from rhodobacter sphaeroides r-26: the cofactors. | the three-dimensional structure of the cofactors of the reaction center of rhodobacter sphaeroides r-26 has been determined by x-ray diffraction and refined at a resolution of 2.8 a with an r value of 26%. the main features of the structure are similar to the ones determined for rhodopseudomonas viridis [michel, h., epp, o. & deisenhofer, j. (1986) embo j. 5, 2445-2451]. the cofactors are arranged along two branches, which are approximately related to each other by a 2-fold symmetry axis. the st ... | 1987 | 3303032 |
| electron microscopical investigation of citrate lyase single molecules. | electron micrographs of citrate lyase from rhodopseudomonas gelatinosa and klebsiella aerogenes reveal two characteristic molecular forms. the "basket" form and the "star" form were subjected to two-dimensional image reconstruction using a technique involving averaging of superposed single molecular images after rotational correlation. a three-dimensional image reconstruction shows that the images of these forms can be interconverted by rotation and that they therefore represent different views ... | 1987 | 3304340 |
| membrane topography of anaerobic carbon monoxide oxidation in rhodocyclus gelatinosus. | rhodocyclus gelatinosus 1 grows anaerobically in the dark at the expense of carbon monoxide. topographical studies with methyl viologen as the membrane probe indicated that co oxidation and h2 production sites were on the cytoplasmic side of the cell membrane. membrane-associated hydrogen gas production appeared to be a unidirectional reaction. in the dark, strain 1 whole cells oxidized co and incorporated about 306 pmol of 32pi into atp per min per mg of protein. with co as the sole energy-yiel ... | 1987 | 3308854 |
| the stark effect in reaction centers from rhodobacter sphaeroides r-26 and rhodopseudomonas viridis. | the effect of an electric field on the optical absorption (stark effect) of reaction centers (rcs) from rhodobacter sphaeroides and rhodopseudomonas viridis embedded in films of poly(vinyl alcohol) was measured. the infrared bands were investigated at 295 k and 77 k. in rcs from rp. viridis at 77 k six peaks (at 982, 849, 835, 818, 803, and 787 nm), associated with the qy transitions of the six pigments, were resolved; in addition, a small broad band at 865 nm was resolved. in rcs from rb. sphae ... | 1987 | 3313396 |
| mechanism of nitrogenase switch-off by oxygen. | oxygen caused a reversible inhibition (switch-off) of nitrogenase activity in whole cells of four strains of diazotrophs, the facultative anaerobe klebsiella pneumoniae and three strains of photosynthetic bacteria (rhodopseudomonas sphaeroides f. sp. denitrificans and rhodopseudomonas capsulata strains ad2 and bk5). in k. pneumoniae 50% inhibition of acetylene reduction was attained at an o2 concentration of 0.37 microm. cyanide (90 microm), which did not affect acetylene reduction but inhibited ... | 1987 | 3542974 |
| on the role of the light-harvesting b880 in the correct insertion of the reaction center of rhodobacter capsulatus and rhodobacter sphaeroides. | the purple, non-sulfur photosynthetic bacteria rhodobacter capsulatus and rhodobacter sphaeroides have two types of pigment-protein complexes that absorb incident light and funnel it to the photochemical reaction center. one of these, b880, is present at an essentially constant ratio to the reaction center, while the abundance of the other, b800-850, varies with growth conditions. independent work in our two laboratories has indicated that while the absence of b800-850 permits photosynthetic gro ... | 1987 | 3552732 |
| 3-hydroxyisobutyrate dehydrogenase, an impurity in commercial 3-hydroxybutyrate dehydrogenase. | the enzymic determination of d-3-hydroxybutyrate and acetoacetate normally involves the use of 3-hydroxybutyrate dehydrogenase (hbdh, ec 1.1.1.30) of bacterial origin. we show that hbdh from rhodopseudomonas spheroides (bcl, grade ii) contains a 3-hydroxyisobutyrate dehydrogenase (hibdh) activity: activity with 3-hydroxyisobutyrate as substrate was greater than 10% of that with 3-hydroxybutyrate. however, hbdh could be prepared essentially free of hibdh activity by incubation at 37 degrees c in ... | 1987 | 3494445 |
| preliminary characterization by x-ray diffraction of crystals of photochemical reaction centres from wild-type rhodopseudomonas spheroides. | reaction centres from wild-type rhodopseudomonas spheroides (strain y) in a solution of octylglucoside have been crystallized with polyethylene glycol as precipitant, either by vapour diffusion or dialysis. orthorhombic crystals (space group p2(1)2(1)2(1)) diffract to 3.5 a resolution. the unit cell parameters are a = 142.5 a, b = 141.5 a, c = 80 a; they are compatible with the presence of one reaction centre per asymmetric unit. | 1987 | 3496461 |
| structural gene of cytochrome b-562 from the cytochrome b-c1 complex of rhodobacter sphaeroides. | the structural gene coding for cytochrome b-562 isolated from the cytochrome b-c1 complex of rhodobacter (rhodopseudomonas) sphaeroides has been cloned. its nucleotide sequence has been determined and the amino acid sequence was deduced therefrom. it consists of 157 amino acids (mr 17,237) and contains four hydrophobic segments. the first 30 residues in the predicted amino acid sequence are the same as those determined for the nh2-terminal portion of purified cytochrome b-562. the amino acid com ... | 1987 | 3502345 |
| flash-induced proton release in rhodopseudomonas sphaeroides spheroplasts. | proton release by flash excitations was measured with right-side-out vesicles prepared from rhodopseudomonas sphaeroides by lysozyme-edta treatment followed by hypotonic treatment. absorbance change at 586 nm in the presence of bromcresol purple was measured to monitor the ph change. in the presence of horse heart cytochrome c, which catalyzes the electron transfer from the cytochrome b-c1 complex to the primary electron donor, the single-turnover flash elicited release of about two protons per ... | 1987 | 3032925 |
| purification and some characteristics of nitrous oxide reductase from paracoccus denitrificans. | nitrous oxide reductase from the denitrifying bacterium paracoccus denitrificans has been purified very nearly to homogeneity by an anaerobic procedure that results in a product with high specific activity. the enzyme is a dimer of about mr 144,000 composed of two subunits of apparently equal mr and contains 4 mol of cu per mol of subunit. the isoelectric point is 4.3; specific activity at 25 degrees c, ph 7.1, is 122 mumol x min-1 x mg of protein-1; and km is about 7 microm n2o under the same c ... | 1987 | 3032972 |
| construction of a transposon containing a gene for polygalacturonate trans-eliminase from klebsiella oxytoca. | a dna fragment containing a klebsiella oxytoca gene for polygalacturonate trans-eliminase was cloned into the kanamycin resistance transposon tn5. this new transposon, designated tn5-pga+, had a transposition frequency of 1 x 10(-6). the broad host range plasmid pr751::tn5-pga+ was conjugally transferred to a variety of genetic backgrounds. the ability to degrade polygalacturonate was expressed in aeromonas hydrophila, alcaligenes eutrophus, azotomonas insolita, escherichia coli, pseudomonas put ... | 1987 | 3034186 |
| spectral properties of cytochrome c' from rhodopseudomonas capsulata b100 and its co complex. | the spectral properties of cytochrome c' from photosynthetic bacterium rhodopseudomonas capsulata (= rhodobacter capsulatus) b100 and its co complex are reported. the electronic absorption, mcd, and epr spectra have been compared with those of the other cytochromes c' and horse heart cytochrome c. epr and electronic spectral results for the ferric cytochrome c' suggest that the ground state of heme-iron(iii) at neutral ph consists of a quantum mechanical admixture of an intermediate-spin and a h ... | 1987 | 3034243 |
| spectral properties of nitric oxide complex of cytochrome c' from rhodopseudomonas capsulata b100. | the spectral properties for no complexes of ferric and ferrous cytochrome c' from photosynthetic bacterium rhodopseudomonas capsulata b100 are reported. the electronic absorption, mcd, and epr spectra have been compared with those of the no complexes of the other cytochromes c' and horse heart cytochrome c. the no-ferrous cytochrome c' would be a mixture of no complexes with six- and five-coordinate nitrosylheme, suggesting that the heme-iron to histidine bond in the ferrous cytochrome c' is mor ... | 1987 | 3036144 |
| organization of phosphoribulokinase and ribulose bisphosphate carboxylase/oxygenase genes in rhodopseudomonas (rhodobacter) sphaeroides. | a heterologous phosphoribulokinase (prk) gene probe was used to analyze two recombinant plasmids isolated from a rhodopseudomonas (rhodobacter) sphaeroides gene library. these plasmids were previously shown to carry the genes for form i and form ii ribulose 1,5-bisphosphate carboxylase/oxygenase (rubpc/o). southern blot hybridization analysis indicated that there were two prk genes linked to the rubpc/o coding sequences. restriction mapping showed the arrangement of the duplicate sets of prk and ... | 1987 | 3038848 |
| reaction centers from rhodopseudomonas sphaeroides in reconstituted phospholipid vesicles. i. structural studies. | reaction centers (rcs) from rhodopseudomonas sphaeroides were reconstituted into asolectin vesicles by cosonication. equilibrium centrifugation on sucrose gradients showed that the vesicles were homogeneous in density (i.e., lipid-to-protein ratio) when reconstituted at a molar lipid-to-protein ratio between 500 to 1000. at lower ratios, a considerable fraction of rcs was not incorporated into closed vesicles, while at higher ratios, an increasing population of liposomes was protein-free. the av ... | 1987 | 3040696 |
| reaction centers from rhodopseudomonas sphaeroides in reconstituted phospholipid vesicles. ii. light-induced proton translocation. | unidirectional light-dependent proton translocation was demonstrated in a suspension of reconstituted reaction center (rc) vesicles supplemented with cytochrome c and 2,3-dimethoxy-5-methyl-1,4-benzoquinone (uq0), a lipid- and water-soluble quinone. proton translocation was detected only at alkaline ph. the ph dependence can be accounted for by the slow redox reaction between the reduced quinone (uq0h2) and oxidized cytochrome c. this conclusion is based on (i) the ph dependence of partial react ... | 1987 | 3040697 |
| a simple, one-step purification of cytochrome b from the bc1 complexes of bacteria. | 1987 | 3030803 | |
| purification of highly active cytochrome bc1 complexes from phylogenetically diverse species by a single chromatographic procedure. | a method has been developed for purification of highly active ubiquinol-cytochrome c oxidoreductase (cytochrome bc1) complexes from wild-type rhodobacter sphaeroides, rhodobacter capsulatus mt1131, bovine heart and yeast mitochondria. this is the first report of the isolation of cytochrome bc1 complex from a wild-type strain of rb. sphaeroides and from any strain of rb. capsulatus. the purification involves extraction of membranes with dodecyl maltoside and two successive deae column chromatogra ... | 1987 | 3032252 |
| homology between bacterial dna and bovine mitochondrial dna encoding cytochrome c oxidase subunit iii. | a segment of mitochondrial dna encoding the bovine cytochrome c oxidase subunit iii gene was isolated and inserted into an escherichia coli plasmid vector. a 556 base pair fragment of the insert dna representing about 70% of the 3'-end of the subunit iii gene was used to search for homology with bacterial dna from strains that contain heme aa3-type cytochrome c oxidases. bacillus subtilis, thermus thermophilus, and ps3 dnas all showed strong hybridization to the probe, whereas paracoccus denitri ... | 1987 | 3032681 |
| isolation and characterization of an aminolevulinate-requiring rhodobacter capsulatus mutant. | using transposon tn5 mutagenesis, we isolated a mutant strain of rhodobacter capsulatus that requires aminolevulinate for growth. southern blot analysis indicated that this strain has a single tn5 insertion. the addition of 0.1 mm aminolevulinate to the medium allowed the mutant to grow either aerobically or photosynthetically with generation times similar to those of the parental strain. when grown photosynthetically, bacteriochlorophyll accumulation increased with increasing aminolevulinate co ... | 1987 | 3029039 |
| o2-dependent nitrogenase switch-off in rhodobacter capsulatus e1f1. | nitrogenase of rhodobacter capsulatus e1f1 (formerly known as rhodopseudomonas capsulata e1f1) was partially resistant to o2 inactivation in vivo. this inactivation was reversed by restoring anaerobic conditions, was independent from de novo protein synthesis and its extent was decreased upon preincubation of the cells with dioxygen at low pressures and also in the presence of h2. illuminated cells exhibited a low rate of o2 uptake which was enhanced in the presence of h2, particularly in cells ... | 1987 | 3268290 |
| biological consequences of segmental alterations in mrna stability: effects of deletion of the intercistronic hairpin loop region of the rhodobacter capsulatus puf operon. | it has been proposed that intercistronic stem and loop structures located in the puf operon of the photosynthetic bacterium rhodobacter capsulatus account for segmental differences in transcript stability and consequently, the differential expression of the b870 and reaction center (rc) proteins encoded by puf. we report here that deletion of these structures leads to a failure to detect as discrete fragments the b870-encoding 0.49 kb and 0.50 kb mrna segments located upstream from the site of t ... | 1987 | 3428264 |
| red blood cell rhodanese: its possible role in modulating delta-aminolaevulinate synthetase activity in mammals. | the optimum conditions for measuring rhodanese activity in human erythrocytes were established. the mean control values for males (112 nmol scn/30 min/mg protein) and females (127 nmol scn/30 min/mg protein) were determined. rhodanese activity was measured in different porphyric patients. the activity was diminished in porphyria cutanea tarda (pct), acute intermittent porphyria (aip), variegate porphyria (vp) and lead intoxication (pb), remaining normal in erythropoietic protoporphyria (epp). de ... | 1987 | 3471602 |
| structural determination of lipid a from gram negative bacteria using laser desorption mass spectrometry. | laser desorption mass spectrometry has been employed for the structural determination of lipid a components derived from the lipopolysaccharides (lps) of gram-negative bacteria. mass spectra were obtained for methylated monophosphoryl lipid a from neisseria gonorrhoeae and rhodopseudomonas sphaeroides, for diphosphoryl lipid a from escherichia coli and for the intact lps from the re mutant of e. coli consisting of triphosphoryl lipid a and two kdo (2-keto-3-deoxyoctonate) units. fragmentation of ... | 1987 | 2962661 |
| in vivo regulation of form i ribulose 1,5-bisphosphate carboxylase/oxygenase from rhodopseudomonas sphaeroides. | when autotrophically grown cells of rhodopseudomonas (rhodobacter) sphaeroides were supplied with an organic carbon source, the activity of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubpc/o) decreased 30 to 60%. the extent of inactivation varied depending on the level of derepression of form i and form ii rubpc/o, and on the nature of the organic carbon source, pyruvate being the most effective. raising the concentration of co2 in the gas phase of autotrophic cultures brought about a simi ... | 1987 | 3107471 |
| malate dehydrogenase in phototrophic purple bacteria: purification, molecular weight, and quaternary structure. | the citric acid cycle enzyme malate dehydrogenase was purified to homogeneity from the nonsulfur purple bacteria rhodobacter capsulatus, rhodospirillum rubrum, rhodomicrobium vannielii, and rhodocyclus purpureus. malate dehydrogenase was purified from each species by either a single- or a two-step protocol: triazine dye affinity chromatography was the key step in purification of malate dehydrogenase in all cases. purification of malate dehydrogenase resulted in a 130- to 240-fold increase in mal ... | 1987 | 3114237 |