Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| dna repair systems in the phototrophic bacterium rhodobacter capsulatus. | uv irradiation and mitomycin c exposure trigger a protease-activity-dependent inhibition of cell division in rhodobacter capsulatus, which begins about 2 h after the treatment is applied. uv irradiation also induces a dose-dependent mutagenesis with a maximal rate between 5 and 10 j m-2, with increased synthesis of a protein of mr approximately 30,000 between 2 and 3 h after uv irradiation. in addition, r. capsulatus has an efficient photoreactivation system that reverses the lethal effects of u ... | 1987 | 3116168 |
| complementation of nitrogen-regulatory (ntr-like) mutations in rhodobacter capsulatus by an escherichia coli gene: cloning and sequencing of the gene and characterization of the gene product. | in vivo genetic engineering by r' plasmid formation was used to isolate an escherichia coli gene that restored the ntr+ phenotype to ntr- mutants of the photosynthetic bacterium rhodobacter capsulatus (formerly rhodopseudomonas capsulata; j. f. imhoff, h. g. trüper, and n. pfenning, int. j. syst. bacteriol. 34:340-343, 1984). nucleotide sequencing of the gene revealed no homology to the ntr genes of klebsiella pneumoniae. furthermore, hybridization experiments between the cloned gene and differe ... | 1987 | 3025172 |
| isolation of the structural genes for the rieske fe-s protein, cytochrome b and cytochrome c1 all components of the ubiquinol: cytochrome c2 oxidoreductase complex of rhodopseudomonas capsulata. | the structural genes for the rieske fe-s protein (peta), cytochrome b (petb) and cytochrome c1 (petc) subunits of the ubiquinol:cytochrome c2 oxidoreductase (bc1 complex) of rhodopseudomonas capsulata have been cloned by complementation, using a mutant defective in this complex. the location of these genes on the obtained plasmid, pr14a, was determined using synthetic mixed oligonucleotide probes corresponding to highly conserved amino acid sequences of these proteins from various organisms. the ... | 1987 | 2821266 |
| primary structure of the bc1 complex of rhodopseudomonas capsulata. nucleotide sequence of the pet operon encoding the rieske cytochrome b, and cytochrome c1 apoproteins. | the nucleotide sequence of the pet operon of rhodopseudomonas capsulata strain sb1003 has been determined. this operon consists of the peta, petb and petc genes, which encode the rieske fe-s protein, cytochrome b and cytochrome c1, respectively, all components of the ubiquinol-cytochrome c2 oxidoreductase. the deduced amino acid sequences of the pet genes show homology to the corresponding proteins from other organisms, and particularly high homologies (over 90% for amino acid and nucleotide seq ... | 1987 | 2821268 |
| crystallization and preliminary analysis of crystals of cytochrome c2 from rhodopseudomonas capsulata. | two crystal forms of the cytochrome c2 isolated from rhodopseudomonas capsulata have been obtained. one crystal form (type i), grown from ammonium sulfate solutions at ph 7.5, belongs to the space group r32 with unit cell dimensions of a = b = 100.0 a, and c = 162.2 a in the hexagonal setting. these crystals most likely contain two molecules in the asymmetric unit. the other crystal form (type ii) was obtained from polyethylene glycol 6000 solutions at ph 6.5. type ii crystals belong to the spac ... | 1987 | 2821271 |
| fbc operon, encoding the rieske fe-s protein cytochrome b, and cytochrome c1 apoproteins previously described from rhodopseudomonas sphaeroides, is from rhodopseudomonas capsulata. | detailed comparison of the 'rhodopseudomonas sphaeroides ga' strain used by gabellini et al. (1985) with genuine r. sphaeroides and r. capsulata strains indicated that the previously reported fbc operon of r. sphaeroides (gabellini and sebald, 1986) encoding the structural genes for the rieske fe-s protein, cytochrome b and cytochrome c1 subunits of the ubiquinol:cytochrome c2 oxidoreductase, is not from r. sphaeroides, but is rather from a strain of r. capsulata. consequently, the genuine bc1 g ... | 1987 | 2821272 |
| purification and properties of dimethylsulfoxide reductase containing a molybdenum cofactor from a photodenitrifier, rhodopseudomonas sphaeroides f.s. denitrificans. | dimethylsulfoxide (dmso) reductase was purified to electrophoretic homogeneity from the periplasmic fraction of a photodenitrifier, rhodopseudomonas sphaeroides f.s. denitrificans. the enzyme had a molecular weight of 82,000 and had no subunit. it contained 1 mol of molybdenum per mol of enzyme, but iron and acid-labile sulfur were not present. the uv-visible spectrum showed only one absorption maximum at 280 nm. denaturation of the enzyme released a molybdopterin cofactor, the fluorescence spec ... | 1987 | 2822679 |
| the amino acid sequence of the cytochrome c2 from the phototrophic bacterium rhodopseudomonas globiformis. | the amino acid sequence of the principal soluble cytochrome c from the phototrophic acidophilic bacterium rhodopseudomonas (or rhodopila) globiformis was determined. by the criteria of percentage sequence identity and fewness of internal insertions and deletions it is more similar in sequence to some mitochondrial cytochromes c than to any known bacterial cytochrome. the organism does not have any properties that commend it as being particularly similar to postulated prokaryotic precursors of th ... | 1987 | 2823792 |
| thermodynamics of carbon monoxide binding to monomeric cytochrome c'. | the thermodynamic parameters for carbon binding to monomeric rhodopseudomonas palustris cytochrome c' are determined. an enthalpy change for co(aq) binding to the cytochrome is measured directly by titration calorimetry as -6.7 +/- 0.2 kcal/mol of heme, the co binding equilibrium constant is measured at 35 degrees c as (1.96 +/- 0.05) x 10(5) m-1, and the binding equilibrium constant at 25 degrees c is calculated from the van't hoff equation as (2.8 +/- 0.1) x 10(5) m-1. comparison of the result ... | 1987 | 2831936 |
| labeling quinone-binding sites in photosynthetic reaction centers: a 38-kilodalton protein associated with the acceptor side of photosystem ii. | 2-acetoxymethyl-1,4-naphthoquinone (2-acomenq) binds with rapid kinetics and high affinity to the primary quinone q(a) site of reaction centers from rhodopseudomonas capsulata. binding of 2-acomenq fully restores electron-transfer activity with kinetics that is similar, but not identical, to that seen with ubiquinone-50. when bound at the q(a) site, 2-acomenq preferentially labels the l subunit. this preference suggests that 2-acomenq labels primarily the region of a quinone-binding site that is ... | 1987 | 16593817 |
| simulation of photochemical hole-burning experiments on photosynthetic reaction centers. | an effective hamiltonian formalism is used to calculate the homogeneous linewidth of long-wavelength absorption in the photosynthetic reaction center. agreement with the experimental values of approximately 400 cm(-1) for the hole width of the 990-nm band of rhodopseudomonas viridis is obtained. the anomalously (two orders of magnitude) large width is explained in terms of resonant coupling to charge transfer states. these results support a dynamical model of primary charge separation [friesner, ... | 1987 | 16593865 |
| factors controlling initial and long-term atp regeneration catalyzed by immobilized chromatophores. | photosynthetic atp regeneration was measured in open reactors using immobilized chromatophores from rhodopseudomonas capsulata. the influence of several factors on both initial and long-term adp photophosphorylation was studied. the effect of phosphate salts and of bovine serum albumin on the organelle activity yield was studied. photophosphorylation was initiated either with adp or regenerated atp and the roles of these nucleotides were compared. different photoreactor configurations were teste ... | 1987 | 18561132 |
| amino acid sequence of the cytochrome subunit of the photosynthetic reaction centre from the purple bacterium rhodopseudomonas viridis. | the complete nucleotide sequence of the gene encoding the cytochrome subunit of the photosynthetic reaction centre from the purple bacterium rhodopseudomonas viridis, and the derived amino acid sequence are presented. the nucleotide sequence of the gene reveals the existence of a typical bacterial signal peptide of 20 amino acid residues which is not found in the mature cytochrome subunit. the gene encoding the cytochrome subunit is preceded by the gene encoding the m subunit. both genes overlap ... | 1987 | 16453786 |
| exciton interactions in reaction centers of the photosynthetic bacterium rhodopseudomonas viridis probed by optical triplet-minus-singlet polarization spectroscopy at 1.2 k monitored through absorbance-detected magnetic resonance. | linear dichroic triplet-minus-singlet [ld-(t - s)] spectra of isolated reaction centers of the photosynthetic bacterium rhodopseudomonas viridis have been measured at 1.2 k with the linear dichroic absorbance-detected magnetic resonance (ld-admr) technique for two mutually perpendicular directions of the preferred axis. the ld-(t - s) spectra have been calibrated with respect to the corresponding (t - s) spectra as a function of applied microwave power and quantitatively interpreted using the fo ... | 1987 | 16578814 |
| stark effect spectroscopy of rhodobacter sphaeroides and rhodopseudomonas viridis reaction centers. | the nature of the initially excited state of the primary electron donor or special pair has been investigated by stark effect spectroscopy for reaction centers from the photosynthetic bacteria rhodopseudomonas viridis and rhodobacter sphaeroides at 77 k. the data provide values for the magnitude of the difference in permanent dipole moment between the ground and excited state, [unk]deltamu[unk], and the angle [unk] between deltamu and the transition dipole moment for the electronic transition. [ ... | 1988 | 16578825 |
| spectroscopic determinants in the reaction center of rhodopseudomonas viridis. | assignments are proposed for the long wavelength absorption bands observed in the reaction center of rhodopseudomonas viridis. the assignments are based on a theoretical treatment in which quantum mechanical calculations are first carried out on the individual chromophores of the reaction center. the energies and wave functions that are obtained are then introduced into an exciton-type perturbation treatment in which extensive configuration interaction is carried out between the excited states o ... | 1988 | 19431719 |
| infrared spectroelectrochemistry of bacteriochlorophylls and bacteriopheophytins: implications for the binding of the pigments in the reaction center from photosynthetic bacteria. | the ir spectra of the bacteriochlorophyll a and b cations and the bacteriopheophytin a and b anions were obtained by using an ir and optically transparent electrochemical cell. prominent effects of radical formation on the vibrational spectra were found for bands assigned to the ester, keto, and acetyl c=o groups and for vibrations from macrocycle bonds. the (radical-minus-neutral) difference spectra are compared to the light-induced difference spectra of the primary donor photooxidation and the ... | 1988 | 16593991 |
| properties of a tn5 insertion mutant defective in the structural gene (frua) of the fructose-specific phosphotransferase system of rhodobacter capsulatus and cloning of the fru regulon. | in photosynthetic bacteria such as members of the genera rhodospirillum, rhodopseudomonas, and rhodobacter a single sugar, fructose, is transported by the phosphotransferase system-catalyzed group translocation mechanism. previous studies indicated that syntheses of the three fructose catabolic enzymes, the integral membrane enzyme ii, the peripheral membrane enzyme i, and the soluble fructose-1-phosphate kinase, are coordinately induced. to characterize the genetic apparatus encoding these enzy ... | 1988 | 2832374 |
| light-driven amino acid uptake in streptococcus cremoris or clostridium acetobutylicum membrane vesicles fused with liposomes containing bacterial reaction centers. | reaction centers of the phototrophic bacterium rhodopseudomonas palustris were introduced as proton motive force-generating systems in membrane vesicles of two anaerobic bacteria. liposomes containing reaction center-light-harvesting complex i pigment protein complexes were fused with membrane vesicles of streptococcus cremoris or clostridium acetobutylicum by freeze-thawing and sonication. illumination of these fused membranes resulted in the generation of a proton motive force of approximately ... | 1988 | 2832381 |
| cytochrome c2-independent respiratory growth of rhodobacter capsulatus. | to assess the role of cytochrome c2 as a respiratory electron carrier, we obtained a double mutant of rhodobacter capsulatus defective in cytochrome c2 and in the quinol oxidase260. this mutant was able to grow chemoheterotrophically, indicating that an electron pathway independent of cytochrome c2 was functional between the ubiquinol:cytochrome c2 oxidoreductase and the cytochrome oxidase410. | 1988 | 2834343 |
| the structural genes coding for the l and m subunits of rhodospirillum rubrum photoreaction center. | in rhodospirillum rubrum, pufl, and pufm, the structural genes coding for the photoreaction center l and m polypeptides, are comprised respectively of 831 and 921 nucleotides. they are separated by a stretch of 12 nucleotides between the taa stop codon of pufl and the first base of the atg initiation codon of pufm. the predicted amino acid sequence of the l and m polypeptides, respectively, contain 275 and 305 residues with corresponding molecular weights of 30,473 and 33,978. their sequences ar ... | 1988 | 2836391 |
| genetic characterization and sequence analysis of the duplicated nifa/nifb gene region of rhodobacter capsulatus. | a dna region showing homology to klebsiella pneumoniae nifa and nifb is duplicated in rhodobacter capsulatus. the two copies of this region are called nifa/nifb copy i and nifa/nifb copy ii. deletion mutagenesis demonstrated that either of the two copies is sufficient for growth in nitrogen-free medium. in contrast, a double deletion mutant turned out to be deficient in nitrogen fixation. the complete nucleotide sequence of a 4838 bp fragment containing nifa/nifb copy i was determined. two open ... | 1988 | 2836706 |
| transcription of oxygen-regulated photosynthetic genes requires dna gyrase in rhodobacter capsulatus. | the regulation of the photosynthetic genes by dna supercoiling in rhodobacter capsulatus has been studied by using gyrase inhibitors in vivo and by measurement of mrna levels of more than a dozen genes. the results demonstrate that the levels of mrna for light-harvesting (i, ii) and reaction center (l, m, h) proteins, bacteriochlorophyll biosynthetic enzymes, ribulose-bisphosphate carboxylase (ec 4.1.1.39), and the mrnas from the open reading frames q and r decreased immediately and dramatically ... | 1988 | 2837760 |
| cloning of the rhodobacter capsulatus hema gene. | portions of the rhodobacter capsulatus hema gene have been cloned from a hema::tn5 insertion strain into the lambda bacteriophage derivative embl3. a cosmid containing the wild-type r. capsulatus hema gene was isolated by complementation of the hema::tn5 mutant. the cosmid contains a 1.4-kilobase ecori fragment that spans the hema::tn5 insertion site. the entire hema gene is contained in this fragment and the adjacent 0.6-kilobase ecori fragment. | 1988 | 2842318 |
| enzymatic properties of ubiquinol:cytochrome c2 oxidoreductase in situ in rhodopseudomonas palustris membranes. | the presence of ubiquinol:cytochrome c2 oxidoreductase was shown in the membranes from a photosynthetic bacterium, rhodopseudomonas palustris. some properties of the enzyme in situ were investigated. the optimal ph of this enzyme activity was 7.0 in the intact membranes. the activity was inhibited by both antimycin and myxothiazol. maximal activity (vmax) was 3-4 mol cytochrome c (c2) reduced/mol cytochrome c1.s. apparent activity of the enzyme with horse heart cytochrome c as the electron accep ... | 1988 | 2846519 |
| transposon mutagenesis and physiological analysis of strains containing inactivated form i and form ii ribulose bisphosphate carboxylase/oxygenase genes in rhodobacter sphaeroides. | strains of rhodobacter sphaeroides (rhodopseudomonas sphaeroides) were constructed such that either the gene encoding form i ribulose 1,5-bisphosphate carboxylase/oxygenase (rubpc-o) or the gene encoding form ii rubpc-o was inactivated. both strains were capable of photoheterotrophic growth with malate as the electron donor, with only slight differences in growth rate and overall carboxylase specific activity compared with the wild-type strain. photolithotrophic growth with 1.5% co2 in hydrogen ... | 1988 | 2826406 |
| electrogenic steps in the redox reactions catalyzed by photosynthetic reaction-centre complex from rhodopseudomonas viridis. | electrogenic and redox events in the reaction-centre complexes from rhodopseudomonas viridis have been studied. in contrast to the previous points of view it is shown that all the four hemes of the tightly bound cytochrome c have different em values (-60, +20, +310 and +380 mv). the first three hemes reveal alpha absorption maxima at 554 nm, 552 nm and 556 nm respectively. the 380-mv heme displays a split alpha band with a maximum at 559 nm and a shoulder at 552 nm. such a splitting is due to no ... | 1988 | 2828052 |
| identification and mapping of nitrogen fixation genes of rhodobacter capsulatus: duplication of a nifa-nifb region. | rhodobacter capsulatus mutants unable to fix nitrogen were isolated by random transposon tn5 mutagenesis. the tn5 insertion sites of 30 nif- mutants were mapped within three unlinked chromosomal regions designated a, b, and c. the majority of tn5 insertions (21 mutants) map within nif region a, characterized by two clai fragments of 2.5 and 25 kilobases (kb). the 17-kb clai fragment of nif region b contains six nif::tn5 insertions, and the three remaining mutations are located on a 32-kb clai fr ... | 1988 | 2828320 |
| posttranscriptional regulation by light of the steady-state levels of mature b800-850 light-harvesting complexes in rhodobacter capsulatus. | photosynthetic organisms exhibit a variety of responses to changes in light intensity, including differential biosynthesis of chlorophyll-protein complexes. cultures of rhodobacter capsulatus grown anaerobically with a low intensity of light (2 w/m2) contained about four times as much b800-850 light-harvesting complex as cells grown under high light intensity (140 w/m2). the mrna transcripts encoding b800-850 beta and alpha peptides were analyzed by northern blot (rna blot), s1 nuclease protecti ... | 1988 | 2448296 |
| an intercistronic stem-loop structure functions as an mrna decay terminator necessary but insufficient for puf mrna stability. | segmental differences in stability within the polycistronic transcripts of the puf operon contribute to differential expression of photosynthesis genes in r. capsulatus. the comparatively stable 5' segment of these transcripts ends in a large intercistronic stem-loop structure. we show here that deletion of this rna hairpin destabilizes the 5' puf mrna segment but that its insertion at the 3' end of the puf operon transcripts fails to stabilize the labile 3' puf mrna segment. evidence is present ... | 1988 | 2449287 |
| a phylogenetic survey of budding, and/or prosthecate, non-phototrophic eubacteria: membership of hyphomicrobium, hyphomonas, pedomicrobium, filomicrobium, caulobacter and "dichotomicrobium" to the alpha-subdivision of purple non-sulfur bacteria. | the phylogenetic position of various budding and/or or prosthecate gram-negative eubacteria was determined by different methods. members of the genera hyphomicrobium, filomicrobium, pedomicrobium were investigated by 16s rrna cataloguing, a 1373 nucleotide long portion of the 16s rrna was sequenced from hyphomicrobium vulgare and the 5s rrnas were analyzed from two hyphomicrobium strains, hyphomonas polymorpha and caulobacter crescentus. comparison with published sequences indicated a membership ... | 1988 | 2455491 |
| analysis of the rhodobacter capsulatus puf operon. location of the oxygen-regulated promoter region and the identification of an additional puf-encoded gene. | in an attempt to identify features of an oxygen-regulated promoter, we have determined the location of transcription initiation for the puf operon. the position for the oxygen-regulated promoter was demonstrated by several independent means to be located 699 base pairs (bp) upstream from the pufb structural gene. dna sequence analysis of the promoter region demonstrates the presence of a 26-base pair region of dyad symmetry followed by a sequence containing homology to promoters which use the rn ... | 1988 | 3127391 |
| prokaryotic hopanoids: the biosynthesis of the bacteriohopane skeleton. formation of isoprenic units from two distinct acetate pools and a novel type of carbon/carbon linkage between a triterpene and d-ribose. | incorporation of 13c-labelled acetate into the hopanoids of the purple non-sulfur bacteria rhodopseudomonas palustris and rhodopseudomonas acidophila and the facultative methylotroph methylobacterium organophilum showed that the bacteriohopane skeleton is built from an unique carbon/carbon linkage between the triterpenic hopane moiety and the c-5 carbon of a d-ribose derivative arising from the non-oxidative pentose phosphate pathway. furthermore a probable compartmentation of the acetate metabo ... | 1988 | 3136017 |
| malate dehydrogenases in phototrophic purple bacteria. thermal stability, amino acid composition and immunological properties. | purified malate dehydrogenases from four species of non-sulphur purple phototrophic bacteria were examined for their heat-stability, amino acid composition and antigenic relationships. malate dehydrogenase from rhodospirillum rubrum, rhodobacter capsulatus and rhodomicrobium vannielii (which are all tetrameric proteins) had an unusually high glycine content, but the enzyme from rhodocyclus purpureus (which is a dimer) did not. r. rubrum malate dehydrogenase was extremely heat-stable relative to ... | 1988 | 3137931 |
| physiological and 15n-nmr analysis of molecular nitrogen fixation by methanococcus thermolithotrophicus, methanobacterium bryantii and methanospirillum hungatei. | two mesophilic methanogenic bacteria, methanobacterium bryantii strain moh and methanospirillum hungatei strain gp1 were demonstrated, using several different experimental approaches, to fix dinitrogen. evidence includes (1) growth with n2 as the sole nitrogen source; (2) incorporation of 15n2 into cellular material (both soluble amino acid pools and insoluble cell protein and other macromolecules) detected by 15n-nmr spectroscopy; (3) acetylene reduction to ethylene by the cells, and inhibition ... | 1988 | 3167101 |
| rhodobacter capsulatus puf operon encodes a regulatory protein (pufq) for bacteriochlorophyll biosynthesis. | biosynthesis of the photochemical apparatus by purple nonsulfur photosynthetic bacteria is known to be inhibited by molecular oxygen and high light intensity. polypeptides that bind bacteriochlorophyll (bchl) to form the light-harvesting i (lh-i) and reaction-center (rc) complexes are encoded by a single transcriptional unit termed the puf operon. in this investigation we demonstrate that the first structural gene in the puf operon (pufq) of rhodobacter capsulatus encodes a protein that is requi ... | 1988 | 3174621 |
| structure of the reaction center from rhodobacter sphaeroides r-26 and 2.4.1: protein-cofactor (bacteriochlorophyll, bacteriopheophytin, and carotenoid) interactions. | the three-dimensional structures of the cofactors and protein subunits of the reaction center (rc) from the carotenoidless mutant strain of rhodobacter sphaeroides r-26 and the wild-type strain 2.4.1 have been determined by x-ray diffraction to resolutions of 2.8 a and 3.0 a with r values of 24% and 26%, respectively. the bacteriochlorophyll dimer (d), bacteriochlorophyll monomers (b), and bacteriopheophytin monomers (phi) form two branches, a and b, that are approximately related by a twofold s ... | 1988 | 3186702 |
| ammonia-constitutive nitrogen fixation mutants of rhodobacter capsulatus. | mutants of r. capsulatus that express nif genes constitutively with respect to ammonia were studied in order to define better the circuit that regulates nif gene transcription. one mutant class could be complemented in trans by a cosmid clone containing a wild-type gene (nifr5) defined by tn5 inserts as being no longer than 1.6 kb. the nifr5 gene is unlinked to previously described nif genes. a second mutant class could not be complemented by the wild-type cosmid library. for one mutant in this ... | 1988 | 3215528 |
| mechanism of puf mrna degradation: the role of an intercistronic stem-loop structure. | the puf photosynthesis operon of rhodobacter capsulatus encodes two major classes of mrna: operon-length pufbalmx transcripts and short pufba messages. the pufba messages, which end in a large intercistronic stem-loop structure, are long-lived processing products of the puf operon transcripts. decay of the labile puflmx segment of the operon-length transcripts begins with non-random endonucleolytic cleavage well downstream of the intercistronic hairpin structure. this hairpin, which is necessary ... | 1988 | 3243429 |
| location of fatty acids in lipid a obtained from lipopolysaccharide of rhodopseudomonas sphaeroides atcc 17023. | monophosphoryl lipid a (mla) obtained from the lipopolysaccharide of rhodopseudomonas sphaeroides atcc 17023 was initially purified by silicic acid column chromatography to yield a single major pentaacyl mla fraction. this fraction was methylated and further purified by reverse-phase high performance liquid chromatography to yield three prominent peak fractions. laser desorption mass spectrometry of these three fractions allowed us to complete the important structural analysis of lipid a from th ... | 1988 | 3258599 |
| spectroscopic evidence for a porphobilinogen deaminase-tetrapyrrole complex that is an intermediate in the biosynthesis of uroporphyrinogen iii. | incubation of porphobilinogen (pbg) with pbg deaminase from rhodopseudomonas sphaeroides in carbonate buffer (ph 9.2) to total pbg consumption resulted in low yields of uroporphyrinogen i (uro'gen i). in the reaction mixture a pyrrylmethane accumulated, which at longer incubation periods was transformed into uro'gen i. the accumulated pyrrylmethane gave an ehrlich reaction which was different from that of a 2-(aminomethyl)dipyrrylmethane or 2-(aminomethyl)tripyrrane. it resembled that of a bilan ... | 1988 | 3262369 |
| adaptive response to simple alkylating agents in the phototrophic bacteria rhodobacter capsulatus and r.sphaeroides. | the presence of an adaptive response to low doses of alkylating chemicals in the phototrophic bacteria rhodobacter sphaeroides and r.capsulatus has been studied. results obtained show that both strains display this repair response against the challenge doses of n-methyl-n'-nitro-n-nitrosoguanidine (mnng), when they are pretreated with low doses of this compound for 120 min. the adaptive response of both r.sphaeroides and r.capsulatus induced an increase of cell survival and a decrease of mutagen ... | 1988 | 3288840 |
| electron transfer in a genetically modified bacterial reaction center containing a heterodimer. | time-resolved optical measurements encompassing the femtoseconds to seconds time scales have been used to investigate rhodobacter capsulatus reaction centers (rcs) in which the histidine residue at position 200 on the m polypeptide has been changed to a leucine by site-directed mutagenesis. the hism200----leu rc, which has a heterodimer consisting of a bacteriochlorophyll and a bacteriopheophytin, is capable of the primary photochemistry observed in wild-type rb. capsulatus rcs, but with an over ... | 1988 | 3051000 |
| structure of the reaction center from rhodobacter sphaeroides r-26: protein-cofactor (quinones and fe2+) interactions. | the three-dimensional structure of the reaction center (rc) from rhodobacter sphaeroides has been determined by x-ray diffraction to a resolution of 2.8 a with an r value of 24%. the interactions of the protein with the primary quinone, qa, secondary quinone, qb, and the nonheme iron are described and compared to those of rcs from rhodopseudomonas viridis. structural differences between the qa and qb environments that contribute to the function of the quinones (the electron transfer from qa- to ... | 1988 | 3054889 |
| pleiotropic effects of localized rhodobacter capsulatus puf operon deletions on production of light-absorbing pigment-protein complexes. | the polycistronic puf operon of rhodobacter capsulatus encodes protein components for the photosynthetic reaction center and one of the two antenna complexes involved in the capture of light energy. we report here that deletions within specific puf genes alter the synthesis and/or assembly in the photosynthetic membranes of pigment-protein complexes not affected genetically by the deletion. the pufx gene is required for normal ratios of antenna complexes, and its deletion results in an increase ... | 1988 | 3056917 |
| electron transfer in monolayer assemblies and energy storage in photosynthetic bacteria. | 1988 | 3074639 | |
| reaction centers of photosynthetic bacteria. | 1988 | 3076277 | |
| different lipid a types in lipopolysaccharides of phototrophic and related non-phototrophic bacteria. | lipid a analyses confirm not only the present taxa of the purple nonsulfur bacteria (formerly rhodospirillaceae), but also phylogenetical relatedness of distinct phototrophic to distinct non-phototrophic bacteria, as was suggested by cataloguing 16s rrna. for example, lipid a with ester-bound 3-oh-10:0 and the rare amide-linked 3-oxo-14:0 is common to the phototrophic rhodobacter capsulatus and rhodobacter sphaeroides and also to paracoccus denitrificans and thiobacillus versutus. 'lipid adag' ( ... | 1988 | 3078741 |
| the hopanoids of the purple non-sulfur bacteria rhodopseudomonas palustris and rhodopseudomonas acidophila and the absolute configuration of bacteriohopanetetrol. | five complex hopanoids have been detected in the purple non-sulfur bacterium rhodopseudomonas acidophila. next to the polyfunctionalized methylcyclopentane bacteriohopanetetrol ether already isolated from methylobacterium organophilum, 35-carbamoylbacteriohopane-32,33,34-triol, 34,35-dicarbamoylbacteriohopane-32,33-diol and two nucleoside analogues, (22r)-30-(5'-adenosyl)hopane and (22s)-30-(5'-adenosyl)hopane were isolated and identified by spectroscopic and chemical methods. in rhodopseudomona ... | 1988 | 3338464 |
| the action of the sesquiterpenic benzoquinone, perezone, on electron transport in biological membranes. | perezone (2-(1,5-dimethyl-4-hexenyl)-3-hydroxymethyl-p-benzoquinone) is a sesquiterpenic benzoquinone isolated from roots of plants of the genus perezia. it exhibits oxido-reduction characteristics which suggest that the compound can be used for studies of the electron transfer chain of rat liver mitochondria. perezone at 50 microm inhibits mitochondrial electron transport through a process which differs from that of rotenone, amytal, and antimycin a. the inhibition is temperature dependent; at ... | 1988 | 3341744 |
| purification and properties of benzoate-coenzyme a ligase, a rhodopseudomonas palustris enzyme involved in the anaerobic degradation of benzoate. | a soluble benzoate-coenzyme a (coa) ligase was purified from the phototrophic bacterium rhodopseudomonas palustris. synthesis of the enzyme was induced when cells were grown anaerobically in light with benzoate as the sole carbon source. purification by chromatography successively on hydroxylapatite, phenyl-sepharose, and hydroxylapatite yielded an electrophoretically homogeneous enzyme preparation with a specific activity of 25 mumol/min per mg of protein and a molecular weight of 60,000. the p ... | 1988 | 3350788 |
| identification of a new bradyrhizobium japonicum gene (frxa) encoding a ferredoxinlike protein. | an open reading frame of 74 codons was identified downstream of the nifb gene of bradyrhizobium japonicum 110. the predicted amino acid sequence shared 63% similarity with the rhodopseudomonas palustris ferredoxin i sequence. we propose to name the gene frxa. the frxa gene was found to be cotranscribed with the nifb gene. an insertion mutation within frxa hardly affected nitrogen fixation activity. | 1988 | 3350797 |
| the complete amino acid sequences of the b800-850 antenna polypeptides from rhodopseudomonas acidophila strain 7750. | spectrally pure b800-850 light harvesting complexes of rhodopseudomonas acidophila 7750 were prepared by chromatography of ldao-solubilised photosynthetic membranes on whatmann de-52 ion exchange resin. two low molecular mass polypeptides (alpha, beta) have been isolated by organic solvent extraction of the lyophilised b800-850 light harvesting complexes. their primary structures were determined by liquid phase sequencer runs, by the sequence analyses of c-terminal o-iodosobenzoic acid fragments ... | 1988 | 3376519 |
| anaerobic and aerobic metabolism of diverse aromatic compounds by the photosynthetic bacterium rhodopseudomonas palustris. | the purple nonsulfur photosynthetic bacterium rhodopseudomonas palustris used diverse aromatic compounds for growth under anaerobic and aerobic conditions. many phenolic, dihydroxylated, and methoxylated aromatic acids, as well as aromatic aldehydes and hydroaromatic acids, supported growth of strain cga001 in both the presence and absence of oxygen. some compounds were metabolized under only aerobic or under only anaerobic conditions. two other strains, cgc023 and cgd052, had similar anaerobic ... | 1988 | 3377491 |
| transcription of the rhodobacter capsulatus nifhdk operon is modulated by the nitrogen source. construction of plasmid expression vectors based on the nifhdk promoter. | we characterized the rhodobacter capsulatus nifhdk promoter by nucleotide sequencing and nuclease s1 analysis of mrna-protected dna probes. comparison of this promoter to nifp and ntrp promoters from other species reveals extensive homology to the canonical nifp consensus sequence. using lac fusions we have demonstrated that transcription of the nifhdk operon is totally repressed when the growth medium is supplemented with ammonia, becomes fully derepressed in ammonia-free medium, and proceeds a ... | 1988 | 3410321 |
| the dna sequence of the rhodobacter capsulatus nifh gene. | 1988 | 3419937 | |
| involvement of coenzyme a thioesters in anaerobic metabolism of 4-hydroxybenzoate by rhodopseudomonas palustris. | the initial steps of anaerobic 4-hydroxybenzoate degradation were studied in whole cells and cell extracts of the photosynthetic bacterium rhodopseudomonas palustris. illuminated suspensions of cells that had been grown anaerobically on 4-hydroxybenzoate and were assayed under anaerobic conditions took up [u-14c]4-hydroxybenzoate at a rate of 0.6 nmol min-1 mg of protein-1. uptake occurred with high affinity (apparent km = 0.3 microm), was energy dependent, and was insensitive to external ph in ... | 1989 | 2914844 |
| nitrile hydratase of rhodococcus sp. n-774. purification and amino acid sequences. | the nitrile hydratase of rhodococcus sp. n-774 was purified and crystallized. the enzyme is composed of two different subunits (molecular masses: subunit alpha, 28,500 da; subunit beta, 29,000 da). the amino-terminal amino acid sequence of each subunit was determined. there is no sequence homology between the two subunits, suggesting that the peptides originate from different cistrons. the activity of the purified enzyme did not decrease during incubation in the dark, whereas it gradually decrea ... | 1989 | 2920826 |
| localization of phycoerythrin at the lumenal surface of the thylakoid membrane in rhodomonas lens. | the thylakoids of cryptomonads are unique in that their lumens are filled with an electron-dense substance postulated to be phycobiliprotein. in this study, we used an antiserum against phycoerythrin (pe) 545 of rhodomonas lens (gift of r. maccoll, new york state department of health, albany, ny) and protein a-gold immunoelectron microscopy to localize this light-harvesting protein in cryptomonad cells. in sections of whole cells of r. lens labeled with anti-pe 545, the gold particles were not u ... | 1989 | 2921285 |
| porphobilinogenase from rhodopseudomonas palustris. | 1. porphobilinogenase (pbgase) from rp. palustris has been isolated and some properties of a partially purified fraction were studied. 2. pbgase has an optimum ph of 7.4 when activity was expressed in terms of porphyrins formed and two ph maxima at 7.4 and 8.5 when activity was based on the amount of pbg consumed. 3. cyclotetramerization rate and distribution of reaction products were not affected either by the presence or absence of oxygen. 4. two pbgase active species of mol. wt 115,000 and 50 ... | 1989 | 2924537 |
| structural and functional analysis of transcriptional control of the rhodobacter capsulatus puf operon. | we report data indicating that the rhodobacter capsulatus puf operon promoter and the site for its oxygen regulation are located more than 700 base pairs upstream from the previously identified puf genes and have identified the nucleotide sequences that constitute these control signals. a model is proposed in which a polycistronic transcript at least 3.4 kilobases in length is initiated near the o2-regulated promoter and is processed posttranscriptionally by endonucleolytic cleavage at multiple ... | 1989 | 2492501 |
| characterization of the ndhc-psbg-orf157/159 operon of maize plastid dna and of the cyanobacterium synechocystis sp. pcc6803. | the ndhc and orf159 genes of the maize plastid dna (ptdna) were sequenced and maize orf159 was used to screen a library of genomic dna of the blue-green alga synechocystis sp. pcc 6803. the cyanobacterial gene homologous to orf159 (orf157) was isolated and sequenced. in sequencing the region upstream of orf157, reading frames with homology to the ndhc and psbg genes of maize ptdna were identified. the ndhc and psbg genes overlap in the ptdnas of maize, tobacco and marchantia polymorpha, but are ... | 1989 | 2499764 |
| evolutionary conservation of protein regions in the protonmotive cytochrome b and their possible roles in redox catalysis. | the amino acid sequences of the protonmotive cytochrome b from seven representative and phylogenetically diverse species have been compared to identify protein regions or segments that are conserved during evolution. the sequences analyzed included both prokaryotic and eukaryotic examples as well as mitochondrial cytochrome b and chloroplast b6 proteins. the principal conclusion from these analyses is that there are five protein regions--each comprising about 20 amino acid residues--that are con ... | 1989 | 2509716 |
| nucleotide transport in rhodobacter capsulatus. | cytoplasmic membrane vesicles isolated from the gram-negative photosynthetic bacterium rhodobacter capsulatus catalyzed the transport of nucleotides. no transport occurred in the intact bacteria unless they were pretreated with edta. the transport rate was measured by incorporation of radioactive phosphate into externally added adp or by incorporation of nonradioactive phosphate into added labeled adp. the catalytic activities which utilized the added adp were photosynthetic atp synthesis, pi-ad ... | 1989 | 2512281 |
| f1-atpase from rhodopseudomonas blastica. | 1989 | 2535110 | |
| purification and characterization of a dimeric phenylalanine dehydrogenase from rhodococcus maris k-18. | nad+-dependent phenylalanine dehydrogenase (ec 1.4.1.) was purified to homogeneity from a crude extract of rhodococcus maris k-18 isolated from soil. the enzyme had a molecular mass of about 70,000 daltons and consisted of two identical subunits. the enzyme catalyzed the oxidative deamination of l-phenylalanine and several other l-amino acids and the reductive amination of phenylpyruvate and p-hydroxyphenylpyruvate. the enzyme required nad+ as a natural coenzyme. the nad+ analog 3-acetylpyridine ... | 1989 | 2536657 |
| isolation of mutants and genes involved in cytochromes c biosynthesis in rhodobacter capsulatus. | mutants of the photosynthetic bacterium rhodobacter capsulatus that have combined deficiencies in the cytochrome b/c1 complex and other c-type cytochromes have been isolated. these mutants were unable to grow anaerobically in the light or dark but could grow aerobically. cosmids with r. capsulatus wild-type dna that complement the mutants have been used to construct genetic and physical maps of the affected genes. complementation profiles with tn5 and mini-mu insertions in these cosmids and subc ... | 1989 | 2536664 |
| identification and isolation of genes essential for h2 oxidation in rhodobacter capsulatus. | mutants of rhodobacter capsulatus unable to grow photoautotrophically with h2 and co2 were isolated. those lacking uptake hydrogenase activity as measured by h2-dependent methylene blue reduction were analyzed genetically and used in complementation studies for the isolation of the wild-type genes. results of further subcloning and transposon tn5 mutagenesis suggest the involvement of a minimum of five genes. hybridization to the 2.2-kilobase-pair ssti fragment that lies within the coding region ... | 1989 | 2536678 |
| correlation of paramagnetic states and molecular structure in bacterial photosynthetic reaction centers: the symmetry of the primary electron donor in rhodopseudomonas viridis and rhodobacter sphaeroides r-26. | the orientation of the principal axes of the primary electron donor triplet state measured in single crystals of photosynthetic reaction centers is compared to the x-ray structures of the bacteria rhodobacter (rb.) sphaeroides r-26 and rhodopseudomonas (rps.) viridis. the primary donor of rps. viridis is significantly different from that of rb. sphaeroides. the measured directions of the axes indicate that triplet excitation is almost completely localized on the l-subunit half of the dimer in rp ... | 1989 | 2543969 |
| carotenoid biosynthesis in photosynthetic bacteria. genetic characterization of the rhodobacter capsulatus crti protein. | carotenoids are photoprotective pigments present in many photosynthetic and nonphotosynthetic organisms. the desaturation of phytoene into phytofluene is an early step in the biosynthetic pathway that in the photosynthetic bacterium rhodobacter capsulatus is mediated by the product of the crti gene. here we report the sequence of this gene and the identification of crti as a membrane protein of approximate mr 60,000. mutant strains with 5-fold lower or 10-fold higher levels of crti with respect ... | 1989 | 2546948 |
| genes downstream from pucb and puca are essential for formation of the b800-850 complex of rhodobacter capsulatus. | the formation of the light-harvesting complex b800-850 (lh-ii) of rhodobacter capsulatus requires, in addition to the synthesis of the polypeptides alpha and beta (the gene products of puca and pucb), the synthesis of bacteriochlorophyll and carotenoids and the expression of at least one gene localized downstream from the pucba operon. this was concluded from the observation that a tn5 insertion downstream from pucba inhibited the formation of the lh-ii complex and the formation of the pucba mrn ... | 1989 | 2549005 |
| characterization of four herbicide-resistant mutants of rhodopseudomonas viridis by genetic analysis, electron paramagnetic resonance, and optical spectroscopy. | herbicides of the triazine class block electron transfer in the photosynthetic reaction centers of purple bacteria and psii of higher plants. they are thought to act by competing with one of the electron acceptors, the secondary quinone, qb, for its binding site. several mutants of the purple bacterium rhodopseudomonas viridis resistant to terbutryn [2-(methylthio)-4-(ethylamino)-6-(tert-butylamino)-s-triazine] have been isolated by their ability to grow photosynthetically in the presence of the ... | 1989 | 2550055 |
| the cytochrome bc1 complex of rhodobacter sphaeroides can restore cytochrome c2-independent photosynthetic growth to a rhodobacter capsulatus mutant lacking cytochrome bc1. | plasmids encoding the structural genes for the rhodobacter capsulatus and rhodobacter sphaeroides cytochrome (cyt) bc1 complexes were introduced into strains of r. capsulatus lacking the cyt bc1 complex, with and without cyt c2. the r. capsulatus merodiploids contained higher than wild-type levels of cyt bc1 complex, as evidenced by immunological and spectroscopic analyses. on the other hand, the r. sphaeroides-r. capsulatus hybrid merodiploids produced only barely detectable amounts of r. sphae ... | 1989 | 2553670 |
| dna fingerprinting by sampled sequencing. | we describe a method for characterizing dna segments that combines limited sequencing with size separation of restriction fragments. as part of a multistep procedure, 5' overhangs of unknown sequence are generated by cleavage with a class iis restriction enzyme. after labeling of these ends by using dideoxynucleotides tagged with distinctive fluorescent dyes, the restriction fragments are analyzed by polyacrylamide gel electrophoresis and detection of fluorescent emissions using a commercially a ... | 1989 | 2554336 |
| promoter mapping and nucleotide sequence of the bchc bacteriochlorophyll biosynthesis gene from rhodobacter capsulatus. | because there are not yet direct assays for most of the proteins required for differentiation of rhodobacter capsulatus cytoplasmic membrane into photosynthetically competent intracytoplasmic membrane, a molecular inquiry into the mechanism and regulation of this process is difficult. we have, therefore, chosen to isolate r. capsulatus photosynthesis genes by creating in-frame fusions to lac'z vectors, and selecting for those that direct appropriately regulated levels of beta-galactosidase in r. ... | 1989 | 2555268 |
| mutations conferring resistance to quinol oxidation (qz) inhibitors of the cyt bc1 complex of rhodobacter capsulatus. | several spontaneous mutants of the photosynthetic bacterium rhodobacter capsulatus resistant to myxothiazol, stigmatellin and mucidin--inhibitors of the ubiquinol: cytochrome c oxidoreductase (cyt bc1 complex)--were isolated. they were grouped into eight different classes based on their genetic location, growth properties and inhibitor cross-resistance. the petabc (fbcfbc) cluster that encodes the structural genes for the rieske fes protein, cyt b and cyt c1 subunits of the cyt bc1 complex was c ... | 1989 | 2556259 |
| cloning and sequencing of the fbcf, b and c genes encoding the cytochrome b/c1 complex from rhodopseudomonas viridis. | the complete nucleotide sequence of the genes encoding the rieske fes, the cytochrome b and the cytochrome c1 subunits of the ubiquinol-cytochrome c2 oxidoreductase from the photosynthetic purple bacterium rhodopseudomonas viridis, and the derived amino acid sequences are presented. these three genes, fbcf, fbcb and fbcc, are located at contiguous sites of the genome. the dna-deduced amino acid sequences are compared with known primary structures of corresponding proteins from other purple photo ... | 1989 | 2560136 |
| role of glutamine as a direct co-repressor of glutamine synthetase in rhodobacter capsulatus e1f1. | high performance liquid chromatography (hplc) has been used to determine the internal levels of amino acids in rhodobacter capsulatus e1f1 cells, subjected to different treatments and nutritional conditions. glutamine synthetase activity and enzyme concentration correlated negatively with the level of glutamine, suggesting that glutamine per se acts as a co-repressor in the enzyme synthesis. moreover, addition of the specific inhibitor l-methionine-d,l-sulfoximine, that produced an increase in e ... | 1989 | 2566555 |
| allosteric regulation of the state of adenylylation of glutamine synthetase in permeabilized cell preparations of rhodopseudomonas sphaeroides. | following a freeze-thaw cycle, and the treatment of rhodopseudomonas sphaeroides with the nonionic detergent lubrol px, the permeabilized cell suspensions can be assayed directly both for the intracellular levels of glutamine synthetase and the state of adenylylation (i.e. the average number n of adenylylated subunits/dodecameric molecules). it seems that all components of the bicycle system are retained if cells grown with low concentrations of ammonia as the sole nitrogen source are used. the ... | 1989 | 2575389 |
| in photosynthetic reaction centers, the free energy difference for electron transfer between quinones bound at the primary and secondary quinone-binding sites governs the observed secondary site specificity. | the secondary quinone-binding site (qb site) of bacterial reaction centers from rhodobacter sphaeroides is generally regarded to be highly specific for its native ubiquinone-10 molecule. we demonstrate here that this is a misconception rooted in the kinetic methods used to assay for occupancy of a quinone in the qb site. we show that observance of occupancy of the qb site, revealed by kinetic assay, is sensitive to the free-energy difference for electron transfer between the quinone at the prima ... | 1989 | 2649889 |
| microaerophilic growth and induction of the photosynthetic reaction center in rhodopseudomonas viridis. | rhodopseudomonas viridis was grown in liquid culture at 30 degrees c anaerobically in light (generation time, 13 h) and under microaerophilic growth conditions in the dark (generation time, 24 h). the bacterium could be cloned at the same temperature anaerobically in light (1 week) and aerobically in the dark (3 to 4 weeks) if oxygen was limited to 0.1%. oxygen could not be replaced by dimethyl sulfoxide, potassium nitrate, or sodium nitrite as a terminal electron acceptor. no growth was observe ... | 1989 | 2651419 |
| organization and expression of genes for photosynthetic pigments-protein complexes in photosynthetic bacteria. | 1989 | 2653478 | |
| gene transfer system for rhodopseudomonas viridis. | a gene transfer system for rhodopseudomonas viridis was established which uses conjugation with escherichia coli s17-i as the donor and mobilizable plasmids as vectors. initially, plasmids of the incompatibility group p1 (prk290 and prk404) were used. the more effective shuttle vectors between e. coli and r. viridis, pkv1 and pkvs1, were derived from plasmid pbr322 and showed the highest conjugation frequency (10(-2] thus far demonstrated in purple bacteria. it was also demonstrated that rhizobi ... | 1989 | 2666398 |
| the primary structures of the core antenna polypeptides from rhodopseudomonas marina. | the antenna complex b880 of rp. marina has been isolated by applying ion-exchange chromatography on whatman de-52 resin and sucrose density centrifugation of ldao-solubilized photosynthetic membranes. the antenna polypeptides b880-alpha and b880-beta were prepared by organic solvent extraction of extensively dialyzed and freeze-dried b880 antenna complex material or photosynthetic membranes. gel filtration on sephadex lh-60 and ion-exchange chromatography on whatman de-32 resin in the presence o ... | 1989 | 2669779 |
| multiple copies of the coding regions for the light-harvesting b800-850 alpha- and beta-polypeptides are present in the rhodopseudomonas palustris genome. | a reverse-phase hplc system for isolation of the water insoluble alpha- and beta-polypeptides of the light-harvesting complex ii (lh ii) of rhodopseudomonas (rps.) palustris without employment of any detergent was developed. the material obtained was of high purity and suitable for direct microsequence analysis. chromatographic analysis could resolve at least two major beta-polypeptides, beta a and beta b, two major alpha-polypeptides, alpha a and alpha b, and two additional minor polypeptides. ... | 1989 | 2670551 |
| dispersed polaron simulations of electron transfer in photosynthetic reaction centers. | a microscopic method for simulating quantum mechanical, nuclear tunneling effects in biological electron transfer reactions is presented and applied to several electron transfer steps in photosynthetic bacterial reaction centers. in this "dispersed polaron" method the fluctuations of the protein and the electron carriers are projected as effective normal modes onto an appropriate reaction coordinate and used to evaluate the quantum mechanical rate constant. the simulations, based on the crystall ... | 1989 | 2675313 |
| nobel lecture. a structural basis of light energy and electron transfer in biology. | aspects of intramolecular light energy and electron transfer will be discussed for three protein--cofactor complexes, whose three-dimensional structures have been elucidated by x-ray crystallography: components of light-harvesting cyanobacterial phycobilisomes; the purple bacterial reaction centre; and the blue multi-copper oxidases. a wealth of functional data is available for these systems which allows specific correlations between structure and function and general conclusions about light ene ... | 1989 | 2676513 |
| nobel lecture. the photosynthetic reaction centre from the purple bacterium rhodopseudomonas viridis. | in our lectures we first describe the history and methods of membrane protein crystallization, before we show how the structure of the photosynthetic reaction centre from the purple bacterium rhodopseudomonas viridis was solved. then the structure of this membrane protein complex is correlated with its function as a light-driven electron pump across the photosynthetic membrane. finally we draw conclusions on the structure of the photosystem ii reaction centre from plants and discuss the aspects ... | 1989 | 2676514 |
| immunological detection of phytoene desaturase in algae and higher plants using an antiserum raised against a bacterial fusion-gene construct. | immunological characterization of phytoene desaturase, a key enzyme of carotenoid biosynthesis, is reported. for this purpose, a phytoene-desaturase fusion protein has been employed. for its construction 921 base pairs of the crti gene were fused to the n-terminal region of the escherichia coli lacz gene. plasmid pgabx2 resulted from insertion of a bgli - xhoi fragment from the rhodobacter capsulatus carotenoid biosynthesis gene cluster, carrying the crti, crta and crtb genes, into pbr322. a 968 ... | 1989 | 2676534 |
| spectroscopy and electron transfer dynamics of the bacterial photosynthetic reaction center. | 1989 | 2679885 | |
| molecular cloning and sequence analysis of the structural gene of ferredoxin i from the photosynthetic bacterium rhodobacter capsulatus. | the structural gene (fdxn) encoding ferredoxin i (fdi) in the photosynthetic bacterium rhodobacter capsulatus was isolated from a cosmid library by using an oligonucleotide probe corresponding to the n-terminal amino acid sequence of fdi. the nucleotide sequences of the gene and of the 3'- and 5'-flanking regions were determined. the gene fdxn codes for a polypeptide of 64 mino acids having a calculated molecular weight of 6,728. amino acid sequencing of the n- and c-terminal ends of fdi allowed ... | 1989 | 2681157 |
| crystallization and characterization of two crystal forms of the b800-850 light-harvesting complex from rhodopseudomonas acidophila strain 10050. | two different crystal forms of the b800-850-antenna complex from rhodopseudomonas acidophila strain 10050 have been grown. this complex is an integral membrane protein and is isolated as an oligomeric assembly with a molecular weight of approximately 84 kda. this assembly contains six alpha/beta apoprotein pairs, 18 molecules of bacteriochlorophyll a and nine molecules of carotenoid. the first crystal form has dimensions unit cell a = b = 75.8 a, c = 97.5 a with the space group p4 and diffracts ... | 1989 | 2685328 |
| the photosynthetic reaction centre from the purple bacterium rhodopseudomonas viridis. | we first describe the history and methods of membrane protein crystallization, and show how the structure of the photosynthetic reaction centre from the purple bacterium rhodopseudomonas viridis was solved. the structure of this membrane protein complex is correlated with its function as a light-driven electron pump across the photosynthetic membrane. finally we draw conclusions on the structure of the photosystem ii reaction centre from plants and discuss the aspects of membrane protein structu ... | 1989 | 2686774 |
| structure of spheroidene in the photosynthetic reaction center from y rhodobacter sphaeroides. | the structure of the reaction center of y rhodobacter sphaeroides has been solved at 3 a resolution, using the atomic coordinates of the reaction center from the carotenoidless mutant r26 rhodobacter sphaeroides. the structure has been refined by a stimulated annealing with the computer program x-plor, leading to a crystallographic r factor of 0.22 using reflections between 8 and 3 a. the spheroidene molecule which is bound to the y reaction center has been fitted in the electron density map as ... | 1989 | 2687022 |
| the dna sequence of the rhodobacter capsulatus ntra, ntrb and ntrc gene analogues required for nitrogen fixation. | we have determined the dna sequence for the genes nifr1, nifr2 and nifr4 in the photosynthetic bacterium rhodobacter capsulatus. these genes regulate transcription of the nifhdk operon and so limit the expression of nitrogen fixation activity to periods of low environmental concentrations of both oxygen and fixed nitrogen. the sequences of these three genes are similar to components of the ntr regulation system in escherichia coli and klebsiella pneumoniae. the two-component regulatory system of ... | 1989 | 2710108 |
| structural analysis of the nontoxic lipid a of rhodobacter capsulatus 37b4. | lipid a from rhodobacter capsulatus 37b4 consists of a d-glucosaminyl-(beta 1-6)-d-glucosamine disaccharide backbone, carrying diphosphorylethanolamine at c-1 of the reducing glucosamine and phosphorylethanolamine at c-4' of the nonreducing glucosamine. 1,4'-bisphosphorylated lipid a, lacking the polar head groups, was also encountered and contributed to the observed microheterogeneity in the phosphate substitution. the amino functions of both glucosamines are substituted almost entirely by the ... | 1989 | 2714269 |
| lipid a with 2,3-diamino-2,3-dideoxy-glucose in lipopolysaccharides from slow-growing members of rhizobiaceae and from "pseudomonas carboxydovorans". | lipid a's from two bradyrhizobium species and from the phylogenetically closely related species "pseudomonas carboxydovorans" were found to contain 2,3-diamino-2,3-dideoxy-glucose as lipid a backbone sugar. in contrast, three representatives of the genus rhizobium, as well as the phylogenetically related species agrobacterium tumefaciens, contain solely glucosamine as lipid a backbone sugar. these findings support independent studies on the phylogenetical relatedness based on 16s rrna-data of th ... | 1989 | 2719525 |
| nucleotide sequence, organization, and nature of the protein products of the carotenoid biosynthesis gene cluster of rhodobacter capsulatus. | carotenoid pigments are essential for the protection of both photosynthetic and non-photosynthetic tissues from photooxidative damage. although carotenoid biosynthesis has been studied in many organisms from bacteria to higher plants, little is known about carotenoid biosynthetic enzymes, or the nature and regulation of the genes encoding them. we report here the first dna sequence of carotenoid genes from any organism. we have determined the complete nucleotide sequence (11,039 bp) of a gene cl ... | 1989 | 2747617 |
| dna sequence and genetic analysis of the rhodobacter capsulatus nifenx gene region: homology between nifx and nifb suggests involvement of nifx in processing of the iron-molybdenum cofactor. | rhodobacter capsulatus genes homologous to klebsiella pneumoniae nife, nifn and nifx were identified by dna sequence analysis of a 4282 bp fragment of nif region a. four open reading frames coding for a 51,188 (nife), a 49,459 (nifn), a 17,459 (nifx) and a 17,472 (orf4) dalton protein were detected. a typical nifa activated consensus promoter and two imperfect putative nifa binding sites were located in the 377 bp sequence in front of the nife coding region. comparison of the deduced amino acid ... | 1989 | 2747620 |
| [three-dimensional structure of photosynthetic reaction center from purple bacteria]. | 1989 | 2748910 |