TitleAbstractYear(sorted ascending)
n-glycohydrolysis of adenosine diphosphoribosyl arginine linkages by dinitrogenase reductase activating glycohydrolase (activating enzyme) from rhodospirillum rubrum.the reaction catalyzed by the activating enzyme for dinitrogenase reductase from rhodospirillum rubrum has been studied using an adp-ribosyl hexapeptide, obtained from proteolysis of inactive dinitrogenase reductase, and synthetic analogs such as n alpha-dansyl-n omega-adp-ribosylarginine methyl ester. the activating enzyme catalyzed n-glycohydrolysis of the ribosyl-guanidinium linkage releasing adp-ribose and regenerating an unmodified arginyl guanidinium group. optimal glycohydrolysis of the l ...19863090031
reaction intermediate partitioning by ribulose-bisphosphate carboxylases with differing substrate specificities.the carboxylated, 6-carbon reaction intermediate (3-keto-2-carboxyarabinitol 1,5-bisphosphate) from the ribulose-1,5-bisphosphate carboxylase reaction was obtained by denaturing the enzyme with acid during steady-state turnover. carbon-13 nmr analysis indicates that this beta-keto acid exists in solution predominantly as the c-3 ketone (as opposed to the hydrate) form. in neutral solution the intermediate slowly decomposes (t1/2 approximately 1 h) by decarboxylation. this decarboxylation reactio ...19863090034
ribulose 1,5-bisphosphate carboxylase. effect on the catalytic properties of changing methionine-330 to leucine in the rhodospirillum rubrum enzyme.oligonucleotide-directed mutagenesis of cloned rhodospirillum rubrum ribulose bisphosphate carboxylase/oxygenase with a synthetic 13mer oligonucleotide primer was used to effect a change at met-330 to leu-330. the resultant enzyme was kinetically examined in some detail and the following changes were found. the km(co2) increased from 0.16 to 2.35 mm, the km(ribulose bisphosphate) increased from 0.05 to 1.40 mm for the carboxylase reaction and by a similar amount for the oxygenase reaction. the k ...19863092806
structural studies of rubisco from electron density map of ribulose 1,5-bisphosphate carboxylase-oxygenase (rubisco) from tobacco (nicotiana tabacum) has been obtained by x-ray crystallography at a nominal resolution of 0.34 nm. phases were determined by multiple isomorphous replacement with three heavy atom derivatives and then refined by solvent flattening. rubisco is barrel-shaped, and has (422) symmetry. the fourfold axis runs down an open central channel, concentric with the barrel. the molecule measures 10.5 nm along the ...19862878449
purification of a light-harvesting b880 complex from wild-type rhodospirillum rubrum.the light-harvesting b880 complex of rhodospirillum rubrum was purified by a new method which allowed recovery of 66% of the amount present in the crude solubilized extract. electrophoretic analysis of the isolated complex, followed by either coomassie brilliant blue or silver staining, revealed only two low-molecular-weight polypeptides. when compared to a previously described preparation, the stability of the complex was considerably increased. in addition, the new procedure yielded b880 of hi ...19862420229
reconstitution of the h+-atpase complex of rhodospirillum rubrum by the beta subunit of the chloroplast coupling factor 1.a method is described for isolating the beta subunit from spinach chloroplast f1 (cf1). the isolated beta subunit reconstituted an active f1 hybrid with the f1 of rhodospirillum rubrum chromatophores from which the beta subunit had been removed. the cf1 beta subunit was similar to the isolated beta subunit of escherichia coli f1 (gromet-elhanan, z., khananshivili, d., weiss, s., kanazawa, h., and futai, m. (1985) j. biol. chem. 260, 12635-12640) in that it restored a substantial rate of atp hydr ...19862427516
distance between two active-site lysines of ribulose bisphosphate carboxylase from rhodospirillum the absence of a three-dimensional structure of ribulose-bisphosphate carboxylase/oxygenase [3-phospho-d-glycerate carboxy-lyase(dimerizing), ec], we have probed the distance between two active-site lysyl residues (lys-166 and lys-329) of the rhodospirillum rubrum enzyme with 4,4'-diisothiocyano-2,2'-disulfonate stilbene, a covalent cross-linking reagent that spans 12 a. the reagent rapidly inactivated the carboxylase, and a competitive inhibitor provided substantial protection. to r ...198616593786
three-dimensional structure of ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum at 2.9 a resolution.the three-dimensional structure of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from rhodospirillum rubrum has been determined at 2.9 a resolution by x-ray crystallographic methods. the mir-electron density map was substantially improved by two-fold non-crystallographic symmetry averaging. the polypeptide chains in the dimer were traced using a graphics display system with the help of the bones option in frodo. the dimer has approximate dimensions of 50 x 72 x 105 a. the enzyme subu ...198616453738
effect of betaine on enzyme activity and subunit interaction of ribulose-1,5-bisphosphate carboxylase/oxygenase from aphanothece halophytica.the presence of betaine, a quaternary ammonium compound, at a concentration (0.5 molar) reported to accumulate inside aphanothece halophytica in response to increasing external salinity, slightly promoted ribulose-1,5-bisphosphate (rubp) carboxylase activity. kcl at 0.25 molar inhibited rubp carboxylase about 55%. betaine relieved the inhibition by 0.25 m kcl and the original uninhibited activity was restored at 1 m betaine. other osmoregulatory solutes such as sucrose and glycerol also reduced ...198616664941
the evolution of glutathione metabolism in phototrophic microorganisms.of the many roles ascribed to glutathione (gsh) the one most clearly established is its role in the protection of higher eucaryotes against oxygen toxicity through destruction of thiol-reactive oxygen byproducts. if this is the primary function of gsh then gsh metabolism should have evolved during or after the evolution of oxygenic photosynthesis. that many bacteria do not produce gsh is consistent with this view. in the present study we have examined the low-molecular-weight thiol compositio ...198711542078
some evolutionary relationships of the primary biological catalysts glutamine synthetase and rubisco. 19872900091
changes in amino acid and nucleotide pools of rhodospirillum rubrum during switch-off of nitrogenase activity initiated by nh4+ or darkness.amino acid and nucleotide pools were measured in nitrogenase-containing rhodospirillum rubrum cultures during nh4+- or dark-induced inactivation (switch-off) of the fe protein. a big increase in the glutamine pool size preceded nh4+ switch-off of nitrogenase activity, but the glutamine pool remained unchanged during dark switch-off. furthermore, methionine sulfoximine had no effect on the rate of dark switch-off, suggesting that glutamine plays no role in this process. in the absence of nh4+ aza ...19872878918
coreconstitution of bacterial atp synthase with monomeric bacteriorhodopsin into liposomes. a comparison between the efficiency of monomeric bacteriorhodopsin and purple membrane patches in coreconstitution experiments.the conditions for coreconstitution of a bacterial atp synthase and bacteriorhodopsin into lecithin liposomes and for light driven atp synthesis have been optimized. a rate of maximally 280 nmol atp min-1 mg atp synthase-1 was achieved with monomerized bacteriorhodopsin compared with a rate of up to 45 nmol atp min-1 mg-1 found for proteoliposomes containing bacteriorhodopsin in the form of purple membrane patches. the different rates are explained by the finding that monomeric bacteriorhodopsin ...19872883008
amino acid concentrations in rhodospirillum rubrum during expression and switch-off of nitrogenase activity.the amino acid concentrations in the phototrophic bacterium rhodospirillum rubrum were measured during growth under nif-repressing and nif-derepressing conditions. the effects of ammonium, glutamine, darkness, phenazine methosulfate, and the inhibitors methionine sulfoximine and azaserine on amino acid levels of cells were tested. the changes were compared to changes in whole-cell nitrogenase activity and adp-ribosylation of dinitrogenase reductase. glutamate was the dominant amino acid under ev ...19872885306
essentiality of glu-48 of ribulose bisphosphate carboxylase/oxygenase as demonstrated by site-directed mutagenesis.previous reports provide indirect evidence for the presence of glu-48 at the active site of ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum. this possibility has been examined directly by replacement of glu-48 with glutamine via site-directed mutagenesis. this single amino acid substitution does not prevent subunit association or ligand binding. however, the glu-48 mutant is severely deficient in catalytic activity, exhibiting a kcat only 0.05% that of wild-type enzyme. th ...19872886121
activation of mg-atp hydrolysis in isolated rhodospirillum rubrum h+-atpase.the effects of lauryl dimethylamine oxide on the rhodospirillum rubrum h+-atpase have been studied. this detergent activates mg2+-dependent atp hydrolysis in the isolated r. rubrum f0-f1 34-fold, whereas the ca2+-atpase activity is only slightly modified. atpase activation by lauryl dimethylamine oxide enhances the effect on atp hydrolysis exerted by free mg2+ ions. concentrations of free mg2+ in the range of 0.025 mm favor activation while higher concentrations inhibit atpase activity by approx ...19872889424
oxidation of cytochrome c2 and of cytochrome c by reaction centers of rhodospirillum rubrum and rhodobacter sphaeroides. the effect of ionic strength and of lysine modification on oxidation rates.the oxidation of cytochrome c2 by the photooxidized reaction center bacteriochlorophyll, p+-870, in chromatophores of rhodospirillum rubrum can be described using second-order kinetics at all ionic strengths. in a system consisting of isolated r. rubrum reaction centers and purified r. rubrum cytochrome c2, the oxidation of cytochrome c2 also follows second-order kinetics. in both cases, the reaction rates at low ionic strength are weakly dependent on the ionic strength. the data suggest that th ...19872820485
sequence analysis of the alcaligenes eutrophus chromosomally encoded ribulose bisphosphate carboxylase large and small subunit genes and their gene products.the nucleotide sequence of the chromosomally encoded ribulose bisphosphate carboxylase/oxygenase (rubpcase) large (rbcl) and small (rbcs) subunit genes of the hydrogen bacterium alcaligenes eutrophus atcc 17707 was determined. we found that the two coding regions are separated by a 47-base-pair intergenic region, and both genes are preceded by plausible ribosome-binding sites. cotranscription of the rbcl and rbcs genes has been demonstrated previously. the rbcl and rbcs genes encode polypeptides ...19872820933
the reaction domain on rhodospirillum rubrum cytochrome c2 and horse cytochrome c for the rhodospirillum rubrum cytochrome bc1 complex.the interaction of the rhodospirillum rubrum cytochrome bc1 complex with r. rubrum cytochrome c2 and horse cytochrome c was studied using specific lysine modification and ionic strength dependence methods. in order to define the reaction domain on cytochrome c2, several fractions consisting of mixtures of singly labeled carboxydintrophenyl-cytochrome c2 derivatives were employed. fraction a consisted of a mixture of derivatives modified at lysines 58, 81, and 109 on the back of cytochrome c2, wh ...19872820990
incorporation of reaction centers into submitochondrial particles resulting in light induced electron transfer.conditions for the incorporation of reaction centers, isolated from rhodospirillum rubrum, into submitochondrial particles have been studied. incorporation of the reaction centers into the lipid bilayer occurs in both orientations. electron flow from the light activated reaction center to the b-c1 complex is demonstrated. preliminary data on the reaction kinetics of the b cytochromes are given.19872823802
function of lys-166 of rhodospirillum rubrum ribulosebisphosphate carboxylase/oxygenase as examined by site-directed mutagenesis.affinity labeling and comparative sequence analyses have placed lys-166 of ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum at the active site. the unusual nucleophilicity and acidity of the epsilon-amino group of lys 166 (pka = 7.9) suggest its involvement in catalysis, perhaps as the base that enolizes ribulosebisphosphate (hartman, f.c., milanez, s., and lee, e.h. (1985) j. biol. chem. 260, 13968-13975). in attempts to clarify the role of lys-166 of the carboxylase, we ha ...19873102487
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 ...19873114237
isolation and characterization of a subunit form of the light-harvesting complex of rhodospirillum rubrum.a new method is described for the isolation of subunits of the light-harvesting complex from rhodospirillum rubrum (wild type and the g-9 mutant) in yields that approach 100%. the procedure involved treating membrane vesicles with ethylenediaminetetraacetic acid-triton x-100 to remove components other than the light-harvesting complex and reaction center. in the preparation from wild-type cells, a benzene extraction was then employed to remove carotenoid and ubiquinone. the next step involved a ...19873117111
cell-cycle-specific fluctuation in cytoplasmic membrane composition in aerobically grown rhodospirillum rubrum.aerobic growth with synchronous cell division was induced in rhodospirillum rubrum by starvation methods. cells were harvested at different points in the cell cycle. analysis of the composition of the cell envelope prepared by differential centrifugation or density gradient-purified cytoplasmic membrane obtained from cells at different times indicated that the protein/phospholipid ratio fluctuated with the cell cycle. the protein/phospholipid ratio of cell envelope from selection-synchronized ce ...19873119564
methylation-independent and methylation-dependent chemotaxis in rhodobacter sphaeroides and rhodospirillum vivo and in vitro methylation, methanol production assays, and the use of specific antibodies raised against the sensory transducing protein tar in escherichia coli all failed to demonstrate the presence of methyl-accepting chemotaxis proteins (mcps) in the photosynthetic bacterium rhodobacter sphaeroides, although such proteins did exist in another photosynthetic bacterium, rhodospirillum rubrum. the range of chemicals to which rhodobacter sphaeroides responds, the lack of an all-or-none res ...19873119570
intersubunit location of the active site of ribulose-bisphosphate carboxylase/oxygenase as determined by in vivo hybridization of site-directed mutants.ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum is a homodimer of 50.5-kda subunits with two substrate binding sites per molecule of dimer. to determine whether each subunit contains an independent active site or whether the active sites are created by intersubunit interactions, we have used a novel in vivo approach for producing heterodimers from catalytically inactive, site-directed mutants of the carboxylase. when the alleles encoding these mutant proteins are placed se ...19873119577
ribulose 1,5-bisphosphate carboxylase-oxygenase. i. structural, immunochemical and catalytic properties.some structural, immunochemical and catalytic properties are examined for ribulose 1,5-bisphosphate carboxylase-oxygenase from various cellular organisms including bacteria, cyanobacteria, algae and higher plants. the native enzyme molecular masses and the subunit polypeptide compositions vary according to enzyme sources. the molecular masses of the large and small subunits from different cellular organisms, on the other hand, show a relatively high homology due to their well-conserved primary a ...19873120806
molecular organization of photochemical reaction complex in chromatophore membrane from rhodospirillum rubrum as detected by immunochemical and proteolytic analyses.the molecular organization of photochemical reaction (pr) complex in chromatophores from rhodospirillum rubrum was studied by a combination of proteolytic analysis with proteinase k followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunochemical analysis with rabbit polyclonal antibodies against its five subunits (h, m, l, alpha, and beta). the preparations used for comparison were reaction center complex (rc) (composed of h, m, and l), pr complex, and chromatophores (cl ...19873125156
purification and characterization of carbon monoxide dehydrogenase, a nickel, zinc, iron-sulfur protein, from rhodospirillum rubrum.carbon monoxide dehydrogenase (co dehydrogenase) from rhodospirillum rubrum was shown to be an oxygen-sensitive, nickel, iron-sulfur, and zinc-containing protein that was induced by carbon monoxide (co). the enzyme was purified 212-fold by heat treatment, ion-exchange, and hydroxylapatite chromatography and preparative gel electrophoresis. the purified protein, active as a monomer of mr = 61,800, existed in two forms that were comprised of identical polypeptides and differed in metal content. fo ...19873029096
fluorometric assay for adp-ribosylarginine cleavage enzymes.a continuous fluorometric assay for enzyme activities which remove adp-ribose linked to proteins at arginine was developed. the substrate analog, n alpha-dansyl-n omega-(1,n6-etheno-adp-ribosyl)arginine methyl ester, was used to assay the catalytic activities of dinitrogenase reductase activating glycohydrolase from rhodospirillum rubrum and nucleotide pyrophosphatase from crotalus adamanteus. the assay is based on the increase in fluorescent emission by ethenoadenine accompanying the enzyme-cat ...19873032020
laser flash photolysis studies of electron transfer between ferredoxin-nadp+ reductase and several high-potential redox proteins.complex formation and the kinetics of electron transfer between ferredoxin-nadp+ reductase (fnr) and two structurally homologous acidic 4fe-4s high-potential ferredoxins (hipip's) from ectothiorhodospira halophila (hp1 and hp2) and two structurally homologous cytochromes c2 from paracoccus denitrificans and rhodospirillum rubrum (pc2, and rc2, respectively) have been investigated by gel filtration and laser flash photolysis techniques. gel filtration studies indicated that complex formation occu ...19873032236
the soluble c-type cytochromes from the bacterium aquaspirillum itersonii. the complete amino acid sequence of the cytochrome c-550.a complete amino acid sequence is proposed for the cytochrome c-550 isolated from the gram-negative chemo-organotrophic bacterium aquaspirillum itersonii. the sequence, a single polypeptide chain of 111 residues, was deduced from the sequences of peptides obtained by tryptic, thermolytic or chymotryptic digestion. the cytochrome shows a high degree of sequence homology with the cytochrome c2 from the photosynthetic bacterium rhodospirillum rubrum, and the evolutionary implications of this are co ...19873036517
similarities between soluble inorganic pyrophosphatase from yeast and some nucleotide-binding polypeptides. 19873037828
the reaction of cytochromes c and c2 with the rhodospirillum rubrum reaction center involves the heme crevice order to define the interaction domain on rhodospirillum rubrum cytochrome c2 for the photosynthetic reaction center, positively charged lysine amino groups on cytochrome c2 were modified to form negatively charged carboxydinitrophenyl lysines. the reaction mixture was separated into six different fractions by ion exchange chromatography on carboxymethylcellulose and sulfopropyl-sepharose. peptide mapping studies indicated that fraction a consisted of a mixture of singly labeled derivatives m ...19873038904
directly observed 15n nmr spectra of uniformly enriched proteins.the proteins cytochrome c2, cytochrome c', and ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum were enriched in 15n by growth of the organism on 15nh4cl. the proteins were purified to homogeneity and studied by 15n nmr. longitudinal and transverse relaxation times as well as the nuclear overhauser effects were determined for various groups of the proteins which vary in molecular weight from 13,000 to 114,000. the values of these parameters for the amide resonances or for gr ...19873040083
the phosphate-pyrophosphate exchange and hydrolytic reactions of the membrane-bound pyrophosphatase of rhodospirillum rubrum: effects of ph and divalent cations.the relation that exist between the pi-ppi exchange reaction and pyrophosphate hydrolysis by the membrane-bound pyrophosphatase of chromatophores of rhodospirillum rubrum was studied. the two reactions have a markedly different requirement for ph. the optimal ph for hydrolysis was 6.5 mg2+ or pi for the enzyme; mn2+ and co2+ support the pi-ppi exchange reaction partially (50%), but the reaction is slower than with mg2+; other divalent cations like zn2+ or ca2+ do not support the exchange reactio ...19873040698
interaction of horse cytochrome c with the photosynthetic reaction center of rhodospirillum rubrum.mitochondrial cytochrome c (horse), which is a very efficient electron donor to bacterial photosynthetic reaction centers in vitro, binds to the reaction center of rhodospirillum rubrum with an approximate dissociation constant of 0.3-0.5 microm at ph 8.2 and low ionic strength. the binding site for the reaction center is on the frontside of cytochrome c which is the side with the exposed heme edge, as revealed by differential chemical acetylation of lysines of free and reaction-center-bound cyt ...19873040700
structural and evolutionary aspects of the key enzymes in photorespiration; rubisco and glycolate oxidase. 19873135980
production of long-chain alcohols by yeasts.fourteen yeast strains from six genera were analysed for the presence of long-chain alcohols. six strains from three genera contained long-chain alcohols, highest levels being found in candida albicans. the alcohols were identified and determined by tlc, glc and glc-ms. the major long-chain alcohols synthesized by these organisms were saturated, primary alcohols with c14, c16 or c18 chain length. unsaturated long-chain alcohols were not detected. in all strains that produced long-chain alcohols, ...19873327916
the nature of l8 and l8s8 forms of ribulose bisphosphate carboxylase/oxygenase from chromatium vinosum.l8 and l8s8 forms of ribulose bisphosphate carboxylase/oxygenase (rubisco) have been prepared from chromatium vinosum by the extremely mild method of centrifugal fractionation. only the l8s8 form is detectable in crude extracts of this organism. both forms show immunological identify in double diffusion studies using antibody to l subunits of the l8s8 form. l subunits from both l8 and l8s8 enzymes are identical by the criteria of peptides observed after limited proteolysis and n-terminal sequenc ...19873579306
ammonia switch-off of nitrogenase from rhodobacter sphaeroides and methylosinus trichosporium: no evidence for fe protein vivo switch-off of nitrogenase activity by nh4+ is a reversible process in rhodobacter sphaeroides and methylosinus trichosporium ob3b. the same pattern of switch-off in rhodospirillum rubrum is explained by adp-ribosylation of one of the fe protein subunits, however, no evidence of covalent modification could be found in the subunits from either r. sphaeroides or m. trichosporium. fe protein subunits from these organisms showed no variant behaviour on sds-page, nor were they 32p-labeled foll ...19883136733
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 ...19883137931
purification and properties of dinitrogenase reductase adp-ribosyltransferase from the photosynthetic bacterium rhodospirillum rubrum.the enzyme that catalyzes the adp-ribosylation and concomitant inactivation of dinitrogenase reductase in rhodospirillum rubrum has been purified greater than 19,000-fold to near homogeneity. we propose dinitrogenase reductase adp-ribosyltransferase (drat) as the working name for the enzyme. drat activity is stabilized by nacl and adp. the enzyme is a monomer with a molecular mass of 30 kda and is a different polypeptide than dinitrogenase reductase activating glycohydrolase. nad (km = 2 mm), et ...19883141411
oxygen regulation of ribulose 1,5-bisphosphate carboxylase activity in rhodospirillum rubrum.the carboxylase activity of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubpc/o) decreased when an anaerobic culture of rhodospirillum rubrum was exposed to atmospheric levels of oxygen. from 70 to 80% of the activity was lost within 12 to 24 h. inactivation was apparent when the enzyme was assayed in situ (in whole cells) and when activity was measured in dialyzed crude extracts. the quantity of enzyme protein, as estimated from sodium dodecyl sulfate-polyacrylamide gels or as quantified i ...19883142846
oxygen-dependent inactivation of ribulose 1,5-bisphosphate carboxylase/oxygenase in crude extracts of rhodospirillum rubrum and establishment of a model inactivation system with purified enzyme.ribulose 1,5-bisphosphate (rubp) carboxylase/oxygenase (rubpc/o) was inactivated in crude extracts of rhodospirillum rubrum under atmospheric levels of oxygen; no inactivation occurred under an atmosphere of argon. rubp carboxylase activity did not decrease in dialyzed extracts, indicating that a dialyzable factor was required for inactivation. the inactivation was inhibited by catalase. purified rubpc/o is relatively oxygen stable, as no loss of activity was observed after 4 h under an oxygen a ...19883142847
real time computer tracking of free-swimming and tethered rotating cells.a computerized image processing system has been developed that tracks individual free-swimming cells and rotating bacterial cell bodies tethered by their flagella in real time. free-swimming bacteria of rhodobacter sphaeroides, rhodospirullum rubrum, and salmonella typhimurium have been tracked swimming at speeds from 0 to over 120 microns s-1. a high level of discrimination is exerted against noncellular objects, allowing analysis of stopped as well as moving cells. this enabled detection of bo ...19883149876
essentiality of lys-329 of ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum as demonstrated by site-directed mutagenesis.the unusual chemical properties of active-site lys-329 of ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum have suggested that this residue is required for catalysis. to test this postulate lys-329 was replaced with glycine, serine, alanine, cysteine, arginine, glutamic acid or glutamine by site-directed mutagenesis. these single amino acid substitutions do not appear to induce major conformational changes because (i) intersubunit interactions are unperturbed in that the pu ...19883151016
surface-enhanced resonance raman scattering spectroscopy of bacterial photosynthetic membranes. the carotenoid of rhodospirillum rubrum.resonance raman scattering by the carotenoid, spirilloxanthin (spx), in a suspension of chromatophores (cytoplasmic side out) isolated from the photosynthetic bacterium, rhodospirillum rubrum, is greatly enhanced when the membranes are adsorbed onto the surface of an anodized ag electrode. the phenomenon is the basis for surface-enhanced resonance raman scattering (serrs) spectroscopy. the spx serrs peaks observed were at 1505-1510, 1150-1155, and 1000-1005 cm-1 with laser excitation wavelengths ...19883126188
restoration of activity to catalytically deficient mutants of ribulosebisphosphate carboxylase/oxygenase by aminoethylation.substitutions for active-site lysyl residues at positions 166 and 329 in ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum have been shown to abolish catalytic activity. treatment of the cys-166 and cys-329 mutant proteins with 2-bromoethylamine partially restores enzyme activity, presumably as a consequence of selective aminoethylation of the thiol group unique to each protein. amino acid analyses, slow inactivation of the wild-type carboxylase by bromoethylamine, and the fa ...19883127395
thioredoxin from rhodospirillum rubrum: primary structure and relation to thioredoxins from other photosynthetic bacteria.thioredoxin was isolated from a photosynthetic purple nonsulfur bacterium, rhodospirillum rubrum, and its primary structure was determined by high-performance tandem mass spectrometry. the sequence identity of r. rubrum thioredoxin to escherichia coli thioredoxin was intermediate to those of the chlorobium thiosulfatophilum and chromatium vinosum proteins. the results indicate that r. rubrum has an nadp-thioredoxin system similar to that of other photosynthetic purple bacteria.19883129411
evidence supporting lysine 166 of rhodospirillum rubrum ribulosebisphosphate carboxylase as the essential base which initiates catalysis.the epsilon-amino group of lys-166 of rhodospirillum rubrum ribulosebisphosphate carboxylase/oxygenase was postulated as the essential base which initiates catalysis by abstracting the proton at c-3 of ribulose 1,5-bisphosphate (hartman, f. c., soper, t. s., niyogi, s. k., mural, r. j., foote, r. s., mitra, s., lee, e. h., machanoff, r., and larimer, f. w. (1987) j. biol. chem. 262, 3496-3501). to scrutinize this possibility, the site-directed gly-166 mutant, totally devoid of ribulosebisphospha ...19883129424
structure and expression of the puf operon messenger rna in rhodospirillum rhodospirillum rubrum, the genes coding for the alpha and beta polypeptides of the b880 antenna (pufa,b) and the l and m polypeptides of the photoreaction center (pufl,m) are clustered on operon puf. in oxygen-limited cells, the puf mrna is present as species of 2561, 640, and 617 nucleotides. aerated cells contain only traces of these mrnas. the large mrna encodes the alpha,beta, l, and m polypeptides, whereas the small mrnas encode only alpha and beta. s1 nuclease protection mapping showed ...19883131324
tertiary structure of plant rubisco: domains and their contacts.the three-dimensional structure of ribulose-1,5-biphosphate carboxylase-oxygenase (rubisco), has been determined at 2.6 a resolution. this enzyme initiates photosynthesis by combining carbon dioxide with ribulose bisphosphate to form two molecules of 3-phosphoglycerate. in plants, rubisco is built from eight large (l) and eight small (s) polypeptide chains, or subunits. both s chains and the nh2-terminal domain (n) of l are antiparallel beta, "open-face-sandwich" domains with four-stranded beta ...19883133767
adp-ribosylation of dinitrogenase reductase from clostridium pasteurianum prevents its inhibition of nitrogenase from azotobacter vinelandii.the effect of adp-ribosylation of dinitrogenase reductase on its binding to dinitrogenase was investigated. dinitrogenase reductase from clostridium pasteurianum (cp2) was a substrate for the adp-ribosyltransferase and the dinitrogenase-reductase-activating glycohydrolase from rhodospirillum rubrum. adp-ribosylation inactivated cp2 and prevented its formation of a tight complex with dinitrogenase from azotobacter vinelandii (av1). the complex between cp2 and av1 could not be adp-ribosylated once ...19883135803
reconstitution of the b873 light-harvesting complex of rhodospirillum rubrum from the separately isolated alpha- and beta-polypeptides and bacteriochlorophyll a.the light-harvesting complex of rhodospirillum rubrum was reversibly dissociated into its component parts: bacteriochlorophyll and two 6-kilodalton polypeptides. the dissociation of the complex by n-octyl beta-d-glucopyranoside was accompanied by a shift of the absorbance maximum from 873 to 820 nm (a stable intermediate form) and finally to 777 nm. in the latter state, bacteriochlorophyll was shown to be free from the protein. complexes absorbing at 820 and 873 nm could be re-formed from the fu ...19883135833
nickel-deficient carbon monoxide dehydrogenase from rhodospirillum rubrum: in vivo and in vitro activation by exogenous inactive, ni-deficient form of carbon monoxide (co) dehydrogenase [carbon-monoxide:(acceptor) oxidoreductase; ec], designated apo-co dehydrogenase, accumulated in rhodospirillum rubrum when cells were grown in the absence of ni and treated with co. in vivo, both co dehydrogenase activity and hydrogenase activity increased several hundred fold upon addition of 2 microm nicl2. apo-co dehydrogenase was purified to homogeneity and differed from holo-co dehydrogenase only in its activity ...19882829176
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 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 ...19882832374
ph-induced changes in rhodospirillum rubrum cytochrome c2 and subsequent renaturation: an 15n nmr study.the 15n-enriched ferrocytochrome c2 from rhodospirillum rubrum was studied by 15n nmr at different solvent ph values. the mobility and chemical shift of the n-terminal glutamic acid (335.4 ppm at ph 5.1) were found to depend on ph. it was least mobile between ph 8 and 9.0, which is explained in terms of ph-dependent conformational changes and formation of salt linkages and/or hydrogen bonds. the resonances of the lysine side chains are centered around 341.7 ppm at low ph and move upfield with ph ...19882834719
the structural genes coding for the l and m subunits of rhodospirillum rubrum photoreaction 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 ...19882836391
15n and 1h nmr studies of rhodospirillum rubrum cytochrome c2.15n-enriched cytochrome c2 was purified from rhodospirillum rubrum that had been grown on 15nh4cl, and the diamagnetic iron(ii) form of the cytochrome was studied by 15n and 1h nmr spectroscopy. 15n resonances of the four pyrrole nitrogens, the ligand histidine nitrogens, the highly conserved tryptophan indole nitrogen, and some proline nitrogens are assigned. the resonances of the single nonligand histidine are observed only at low ph because of severe broadening produced by proton tautomerizat ...19882837275
regulation of ribulose bisphosphate carboxylase expression in rhodospirillum rubrum: characteristics of mrna synthesized in vivo and in vitro.the synthesis of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubpcase) in rhodospirillum rubrum was regulated by the co2 concentration in the culture medium. the specific activity of rubpcase in cells grown photolithotrophically in low concentrations of co2 (1.5%) was five to ten times higher than that in cultures grown at high concentrations of co2 (10%). increased enzyme activity was reflected by an increase in both rubpcase mrna and rubpcase protein. rubpcase expression was also studied ...19882842301
properties and regulation of the h+-atp synthase of mitochondria.a brief survey is made of the function of the h+-atp synthase of mitochondria with emphasis on how it is regulated. a main regulatory factor is a low molecular weight protein whose binding to the enzyme appears to be essential for optimal accumulation of atp as driven by electron transport. the atp synthase is also controlled by adp that, by binding to a site in the enzyme, inhibits atp hydrolysis. data on the spontaneous synthesis of a tightly bound atp are discussed. apparently, this requires ...19882896020
subtle alteration of the active site of ribulose bisphosphate carboxylase/oxygenase by concerted site-directed mutagenesis and chemical modification.both activities of ribulose bisphosphate carboxylase/oxygenase are dependent on carbamylation by co2 of a specific lysyl epsilon-amino group (lys-191 of the enzyme from rhodospirillum rubrum). to examine the stringency of the requirement for this lysyl side chain, lys-191 was converted to an aminoethylcysteinyl residue (net replacement of a gamma-methylene group by a sulfur atom) by a combination of site-directed mutagenesis and subsequent chemical modification. the purified cys-191 mutant was t ...19882896501
conversion of coupling factor 1 of rhodospirillum rubrum from a ca2+-atpase into a mg2+-atpase.isolation of f1-atpase from rhodospirillum rubrum by chloroform extraction of chromatophores, followed by purification on a glycerol gradient, results in a very pure enzyme preparation containing five subunits with high ca2+-atpase activity (15 mumol per min per mg protein). furthermore, conditions are reported under which the purified f1 exhibits mg2+-dependent atpase activity of about 35 mumol per min per mg protein. nahco3 stimulates the mg2+-activity from 1.5 mumol per min per mg protein to ...19882901272
diethylstilbestrol. interactions with membranes and proteins and the different effects upon ca2+- and mg2+-dependent activities of the f1-atpase from rhodospirillum rubrum.the hydrophobic compound diethylstilbestrol inhibits the generation of the proton gradient and the membrane potential in chromatophores from rhodospirillum rubum and dissipates proton gradients over asolectin vesicle membranes. the ca2+-atpase activity of chromatophores, of purified f0f1-atpase and of purified f1-atpase is also decreased in the presence of diethylstilbestrol. other repressed activities are the pyrophosphatase activity of soluble pyrophosphatase from yeast and the nadh oxidation ...19882901353
dna sequence of a gene cluster coding for subunits of the f0 membrane sector of atp synthase in rhodospirillum rubrum. support for modular evolution of the f1 and f0 sectors.a region was cloned from the genome of the purple non-sulphur photobacterium rhodospirillum rubrum that contains genes coding for the membrane protein subunits of the f0 sector of atp synthase. the clone was identified by hybridization with a synthetic oligonucleotide designed on the basis of the known protein sequence of the dicyclohexylcarbodi-imide-reactive proteolipid, or subunit c. the complete nucleotide sequence of 4240 bp of this region was determined. it is separate from an operon descr ...19882902844
determination of the functional homology of beta subunits isolated from various f1-atpase complexes: their role in catalysis and coupled proton-translocation. 19882458598
populations of anaerobic phototrophic bacteria in a spartina alterniflora salt marsh.habitat-simulating media were used with the hungate anaerobic roll tube technique to enumerate culturable anaerobic photosynthetic bacteria in sediment, tidal waters, and spartina alterniflora plant samples collected from the salt marsh at sapelo island, ga. no phototrophs were detected in samples of creekside (low marsh) sediment or in tidal waters in creekside regions. in the high marsh region, 90% of anaerobic phototrophic bacteria occurred in the top 5 mm of sediment and none were detected b ...198816347646
analysis of chromophytic and rhodophytic ribulose-1,5-bisphosphate carboxylase indicates extensive structural and functional similarities among evolutionarily diverse algae.ribulose-1,5-bisphosphate carboxylase (rubisco) from the algae olisthodiscus luteus (chromophyte) and griffithsia pacifica (rhodophyte) are remarkably similar to each other. however, both enzymes differ significantly in the structure and function when compared to rubisco from green algae and land plants. analysis of purified rubisco from o. luteus and g. pacifica indicates that the size of the holoenzyme and stoichiometry of the 55 and 15 kilodalton subunit polypeptides are approximately 550 kil ...198916667160
division of divalent cations into two groups in relation to their effect on the coupling of the f0f1-atpase of rhodospirillum rubrum to the protonmotive force.divalent cations are divided into two groups in relation to their ability to promote atp synthase catalyzed reactions. in the presence of mg2+, the following pattern rules: (i) uncoupler-stimulated atp hydrolysis of rhodospirillum rubrum chromatophores which shows an optimum concentration of the divalent cation; (ii) atp-induced proton pumping in chromatophores; (iii) light-induced atp synthesis in chromatophores; (iv) no or very low atpase activity of purified f1-atpase unmasked by diethylstilb ...19892482079
carbonyl sulfide: an alternate substrate for but not an activator of ribulose-1,5-bisphosphate carboxylase.carbonyl sulfide, a competitive inhibitor of ribulose-bisphosphate carboxylase with respect to co2 (laing, w. a., and christeller, j. t. (1980) arch. biochem. biophys. 202, 592-600), is an alternate substrate. thiocarboxylation was monitored by mass spectrometry as the stoichiometric consumption of carbonyl sulfide. the product, 1-thio-3-phosphoglycerate, was identified by 13c nmr and uv absorption spectroscopy and measured by enzymic conversion to thiolactate, coupled to the oxidation of nadh. ...19892492523
crystal structure of the binary complex of ribulose-1,5-bisphosphate carboxylase and its product, 3-phospho-d-glycerate.the crystal structure of the binary complex of non-activated ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum and its product 3-phospho-d-glycerate has been determined to 2.9-a resolution. this structure determination confirms the proposed location of the active site (schneider, g., lindqvist, y., brändén, c.-i., and lorimer, g. (1986) embo j. 5, 3409-3415) at the carboxyl end of the beta-strands of the alpha/beta-barrel in the carboxyl-terminal domain. one molecule of ...19892492987
regulation of carbon monoxide dehydrogenase and hydrogenase in rhodospirillum rubrum: effects of co and oxygen on synthesis and activity.exposure of the photosynthetic bacterium rhodospirillum rubrum to carbon monoxide led to increased carbon monoxide dehydrogenase and hydrogenase activities due to de novo protein synthesis of both enzymes. two-dimensional gels of [35s]methionine-pulse-labeled cells showed that induction of co dehydrogenase synthesis was rapidly initiated (less than 5 min upon exposure to co) and was inhibited by oxygen. both co dehydrogenase and the co-induced hydrogenase were inactivated by oxygen in vivo and i ...19892498285
ammonium inhibition of nitrogenase activity in herbaspirillum seropedicae.the effect of oxygen, ammonium ion, and amino acids on nitrogenase activity in the root-associated n2-fixing bacterium herbaspirillum seropedicae was investigated in comparison with azospirillum spp. and rhodospirillum rubrum. h. seropedicae is microaerophilic, and its optimal dissolved oxygen level is from 0.04 to 0.2 kpa for dinitrogen fixation but higher when it is supplied with fixed nitrogen. no nitrogenase activity was detected when the dissolved o2 level corresponded to 4.0 kpa. ammonium, ...19892498287
the orientation of substrate and reaction intermediates in the active site of ribulose-1,5-bisphosphate carboxylase.there are four possible orientations of the substrate ribulose 1,5-bisphosphate in the active site of ribulose-1,5-bisphosphate carboxylase. distinction between these four possible orientations has been made on the basis of 31p nmr and borohydride-trapping experiments. the orientation of the reaction-intermediate analog, 2'-carboxy-d-arabinitol 1,5-bisphosphate with respect to the divalent metal ion was determined by 31p nmr studies of the quaternary complex, enzyme.co2.ni2+.2'-carboxyarabinitol ...19892498340
mapping of the puh messenger rnas from rhodospirillum rubrum. evidence for tandem promoters.the mrna transcripts of rhodospirillum rubrum gene puh, coding for the h subunit of the photoreaction center, and of genes flanking puh were analyzed by blot hybridization. open reading frame g115, upstream of structural gene puh, is transcribed as a 2.25-kilobase mrna. gene puh itself is transcribed as two mrnas of 1118 and 1032 nucleotides. mung bean nuclease protection analysis shows that the puh transcripts have different 5' termini within open reading frame g115 and a unique rho-independent ...19892499583
examination of subunit interactions at the active site of ribulose 1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum by hybridization of site-directed mutants.the two active sites of homodimeric ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum are constituted by interacting domains of adjacent subunits, in which residues from each are required for catalytic activity. active-site residues include lys-166 of one domain and glu-48 of the interacting domain from the adjacent subunit. whereas all substitutions for lys-166, introduced by site-directed mutagenesis, abolished catalytic activity, only a negatively charged residue (e.g., a ...19892500136
a cyanobacterial mutant requiring the expression of ribulose bisphosphate carboxylase from a photosynthetic anaerobe.ribulose bisphosphate carboxylase is essential for both photoautotrophic and photoheterotrophic growth of the cyanobacterium synechocystis 6803. however, a mutant lacking cyanobacterial carboxylase could be obtained by replacing the natural carboxylase gene with the corresponding gene from rhodospirillum rubrum, a photosynthetic anaerobe. this treatment produced an organism whose growth depended on the activity of the structurally and functionally dissimilar foreign carboxylase. as a further con ...19892503824
effect of nucleotides on the activity of dinitrogenase reductase adp-ribosyltransferase from rhodospirillum rubrum.the mechanism by which mgadp stimulates the activity of dinitrogenase reductase adp-ribosyltransferase (drat) has been examined by using dinitrogenase reductases from rhodospirillum rubrum, klebsiella pneumoniae, and azotobacter vinelandii as acceptor substrates. in the presence of 0.2 mm nad, maximal rates of adp-ribosylation of all three acceptors were observed at an adp concentration of 150 microm; in the absence of added adp, drat activity with the dinitrogenase reductases from r. rubrum and ...19892504283
nickel is required for the transfer of electrons from carbon monoxide to the iron-sulfur center(s) of carbon monoxide dehydrogenase from rhodospirillum rubrum.the role of nickel in co oxidation and electron flow was investigated in carbon monoxide dehydrogenase from rhodospirillum rubrum. the fe-s centers of oxidized, nickel-containing (holo) co dehydrogenase were completely reduced within 1 min of exposure to co. the fe-s centers of oxidized, nickel-deficient (apo) co dehydrogenase were not reduced during a 35-min incubation in the presence of co. apo-co dehydrogenase fe-s centers were reduced by dithionite. the fe-s centers of cyanide-inhibited, hol ...19892504284
nickel-specific, slow-binding inhibition of carbon monoxide dehydrogenase from rhodospirillum rubrum by cyanide.the inhibition of purified carbon monoxide dehydrogenase from rhodospirillum rubrum by cyanide was investigated in both the presence and absence of co and electron acceptor. the inhibition was a time-dependent process exhibiting pseudo-first-order kinetics under both sets of conditions. the true second-order rate constants for inhibition were 72.2 m-1 s-1 with both substrates present and 48.9 and 79.5 m-1 s-1, respectively, for the reduced and oxidized enzymes incubated with cyanide. co partiall ...19892504285
posttranslational regulatory system for nitrogenase activity in azospirillum spp.the mechanism for "nh4+ switch-off/on" of nitrogenase activity in azospirillum brasilense and a. lipoferum was investigated. a correlation was established between the in vivo regulation of nitrogenase activity by nh4cl or glutamine and the reversible covalent modification of dinitrogenase reductase. dinitrogenase reductase adp-ribosyltransferase (drat) activity was detected in extracts of a. brasilense with nad as the donor molecule. dinitrogenase reductase-activating glycohydrolase (drag) activ ...19892504694
reversible adp-ribosylation of dinitrogenase reductase in a nifd- mutant of rhodospirillum rubrum.dinitrogenase reductase from a rhodospirillum rubrum strain lacking dinitrogenase was reversibly adp-ribosylated in vivo in response to dark-light transitions. addition of ammonia also led to adp-ribosylation in this strain. these results demonstrate that reduced dinitrogenase is a satisfactory substrate for the reversible adp-ribosylation system of r. rubrum in vivo.19892504701
delta ph driven energy-linked nad+ reduction in rhodospirillum rubrum artificial proton gradient provided sufficient energy to drive reverse electron transport from succinate to nadh:ubiquinone oxidoreductase in chromatophores isolated from rhodospirillum rubrum. the ph gradient created was able to reduce nad+. in chromatophores, the optimal rate of nad+ reduction was about 0.4-0.45 mumol nadh formed/min.mumol bacteriochlorophyll at delta ph 3. the presence of oligomycin was an obligate factor in the assay in order to observe the maximal rate of nad+ reduction. ...19892505679
demonstration and partial characterization of adp-ribosylation in pseudomonas maltophilia.adp-ribosylation of proteins occurs in many eukaryotes, and it is also the mechanism of action of a growing number of important bacterial toxins. to date, however, there is only one well-characterized adp-ribosylation system where the adp-ribosyltransferase and the substrate protein are both bacterial in origin, namely within the nitrogen-fixing bacterium rhodospirillum rubrum. the present paper demonstrates the endogenous adp-ribosylation of two proteins of mr 32,000 and 20,000 within pseudomon ...19892505752
genes coding for the reversible adp-ribosylation system of dinitrogenase reductase from rhodospirillum rubrum.nitrogen fixation activity in the photosynthetic bacterium rhodospirillum rubrum is controlled by the reversible adp-ribosylation of the dinitrogenase reductase component of the nitrogenase enzyme complex. this report describes the cloning and characterization of the genes encoding the adp-ribosyltransferase (drat) and the adp-ribosylglycohydrolase (drag) involved in this regulation. these genes are shown to be contiguous on the r. rubrum chromosome and highly linked to the nifhdk genes. sequenc ...19892506427
carbonyl sulfide inhibition of co dehydrogenase from rhodospirillum rubrum.carbonyl sulfide (cos) has been investigated as a rapid-equilibrium inhibitor of co oxidation by the co dehydrogenase purified from rhodospirillum rubrum. the kinetic evidence suggests that the inhibition by cos is largely competitive versus co (ki = 2.3 microm) and uncompetitive versus methylviologen as electron acceptor (ki = 15.8 microm). the data are compatible with a ping-pong mechanism for co oxidation and cos inhibition. unlike the substrate co, cos does not reduce the iron-sulfur centers ...19892510818
coupling of atp hydrolysis to phosphate uptake in rhodospirillum rubrum chromatophores under the influence of ca2+ and mg2+.the pi-atp exchange and atp hydrolytic reactions, by the f0f1 complex, were studied in rhodospirillum rubrum chromatophores in the dark. an optimal ph between 7.0 and 8.5 was determined for the hydrolytic and exchange reactions. under these conditions, the hydrolysis/exchange ratio was approximately 2. the kinetic analysis of the hydrolytic and exchange reactions using mg-atp as substrate showed a change in the hydrolysis/exchange ratio that varied between 2.0 and 2.8 as the substrate concentrat ...19892512287
protein phosphorylation and control of excitation energy transfer in photosynthetic purple bacteria and cyanobacteria.the function of phosphorylation of light-harvesting polypeptides is well characterised in chloroplasts of green plants, but the prokaryotic cyanobacteria and purple photosynthetic bacteria have quite different light-harvesting polypeptides whose structure and function cannot be controlled in precisely the same way. nevertheless, cyanobacteria show light-dependent phosphorylation of membrane polypeptides associated with photosystem ii and with the light-harvesting phycobilisome, and purple bacter ...19892512993
protein phosphorylation in purple photosynthetic bacteria.endogenous protein phosphorylation was shown in both in vitro and in vivo experiments in r. rubrum and in other purple photosynthetic bacteria. among the substrates of this protein kinase activity the apoproteins of the light harvesting complex were tentatively identified. phosphoamino acid analysis revealed the presence of phosphoserine, phosphothreonine and phosphotyrosine in r. rubrum. a tyrosine kinase was partially purified in the same bacteria.19892512995
evolution of antioxidant mechanisms: thiol-dependent peroxidases and thioltransferase among procaryotes.glutathione peroxidase and glutathione s-transferase both utilize glutathione (gsh) to destroy organic hydroperoxides, and these enzymes are thought to serve an antioxidant function in mammalian cells by catalyzing the destruction of lipid hydroperoxides. only two groups of procaryotes, the purple bacteria and the cyanobacteria, produce gsh, and we show in the present work that representatives from these two groups (escherichia coli, beneckea alginolytica, rhodospirillum rubrum, chromatium vinos ...19892515292
functional expression of a rhodospirillum rubrum gene encoding dinitrogenase reductase adp-ribosyltransferase in enteric bacteria.the function of the cloned drat gene of rhodospirillum rubrum was studied by placing it under the control of the tac promoter in the vector, pkk223-3. after induction with isopropyl-beta-d-thiogalactopyranoside, dinitrogenase reductase adp-ribosyltransferase (drat) activity was detected in crude extracts of the heterologous hosts escherichia coli and klebsiella pneumoniae. in addition, the expression of drat produced a nif- phenotype in the otherwise wild-type k. pneumoniae strains, the result o ...19892515993
ability of the phototrophic bacterium rhodospirillum rubrum to produce various poly (beta-hydroxyalkanoates): potential sources for biodegradable polyesters.studies have been carried out in order to optimize growth and culture conditions for the intracellular formation of poly(beta-hydroxyalkanoates) (pha) in the phototrophic, purple, non-sulphur bacterium rhodospirilum rubrum. its potential to produce novel copolymers was investigated. recently, it has become of industrial interest to evaluate these polyesters as potentially biodegradable plastics for a wide range of possible applications. on an industrial scale, the use of photosynthetic bacteria ...19892518731
atp-synthesis by proteoliposomes incorporating rhodospirillum rubrum f0f1 as measured with firefly luciferase: dependence on delta psi and delta ph.atp-synthesis catalyzed by proteoliposomes incorporating rhodospirillum rubrum f0f1 was driven by artificially applied electrochemical proton gradients. the time-course of atp-synthesis was followed continuously by means of firefly luciferase. correction methods were developed which allow one to calculate the initial rate of atp-synthesis from the observed luminescence kinetics. the following results were obtained: (1) atp-synthesis occurred above a threshold delta mu h+ of 90 mv; this threshold ...19892528991
amount and turnover rate of the f0f1-atpase and the stoichiometry of its inhibition by oligomycin in rhodospirillum rubrum chromatophores.the amount of f1-atpase in chromatophores from rhodospirillum rubrum was determined by western blotting using anti-rrf1 rabbit antibodies. 9.1 mmol f1 (mol bacteriochlorophyll)-1 was obtained or 14% of the total protein content of the chromatophores. the turnover rate of the f0f1-atpase was 17 molecules atp s-1 during synthesis, 2 molecules atp s-1 during hydrolysis under coupled conditions with mg2+ as the divalent cation, and 7 molecules atp s-1 during hydrolysis in the presence of carbonyl cy ...19892532130
f1-atpase from rhodopseudomonas blastica. 19892535110
the effect of equisetin on energy-linked reactions in rhodospirillum rubrum chromatophores.light-induced proton uptake, light-induced carotenoid absorbance shift, photophosphorylation, and hydrolysis of mg-atp, ca-atp, and ppi in rhodospirillum rubrum chromatophores are shown to be inhibited by the antibiotic equisetin. the mg- and ca-atpase activities of purified f0f1-atpase are inhibited by equisetin. in contrast, only the ca-atpase activity of purified f1-atpase is decreased by equisetin, whereas the mg-atpase is stimulated. both equisetin and n,n'-dicyclohexylcarbodiimide (dccd) i ...19892536535
extended x-ray absorption fine structure study of rhodospirillum rubrum and rhodospirillum molischianum cytochromes c': relationship between heme stereochemistry and spin exafs study on the oxidized and reduced forms of cytochromes c' from rhodospirillum rubrum and rhodospirillum molischianum was performed at ph 7. the cytochromes c' have an apparent coordination number of 5 in both oxidation states. average fe-ligand bond lengths of 2.02 +/- 0.025 and 2.06 +/- 0.025 a are obtained in their oxidized and reduced forms, respectively. by use of suitable values for the fe-nhis bond length and fe out-of-plane displacement, as determined by small molecule crystallog ...19892541757
steric and hydrophobic effects in alkyl isocyanide binding to rhodospirillum molischianum cytochrome c'.equilibrium constants for the binding of a series of alkyl isocyanides to ferrous cytochrome c' from rhodospirillum molischianum have been measured spectrophotometrically. the equilibrium constants range from 3.3 m-1 to 2.6 x 10(2) m-1 and follow the order methyl greater than ethyl less than n-propyl less than tert-butyl less than n-butyl less than amyl less than cyclohexyl less than n-hexyl. the decrease in equilibrium constant from methyl to ethyl isocyanide provides evidence for a steric inte ...19892541775
examination of the function of active site lysine 329 of ribulose-bisphosphate carboxylase/oxygenase as revealed by the proton exchange reaction.diverse approaches that include site-directed mutagenesis have indicated a catalytic role of lys-329 of ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum. to determine whether lys-329 is required for the initial enolization of ribulose bisphosphate or for some subsequent step in the overall reaction pathway, the competence of position 329 mutant proteins (devoid of carboxylase activity) in catalyzing exchange of solvent protons with the c-3 proton of substrate has now been ex ...19892545684
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