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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
structure and expression of the puf operon messenger rna in rhodospirillum rubrum.in 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
ammonia switch-off of nitrogenase from rhodobacter sphaeroides and methylosinus trichosporium: no evidence for fe protein modification.in 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
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
determination of the functional homology of beta subunits isolated from various f1-atpase complexes: their role in catalysis and coupled proton-translocation. 19882458598
nickel-deficient carbon monoxide dehydrogenase from rhodospirillum rubrum: in vivo and in vitro activation by exogenous nickel.an inactive, ni-deficient form of carbon monoxide (co) dehydrogenase [carbon-monoxide:(acceptor) oxidoreductase; ec 1.2.99.2], 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
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
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
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
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
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
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
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
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
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
structural and evolutionary aspects of the key enzymes in photorespiration; rubisco and glycolate oxidase. 19873135980
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
methylation-independent and methylation-dependent chemotaxis in rhodobacter sphaeroides and rhodospirillum rubrum.in 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
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
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
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
some evolutionary relationships of the primary biological catalysts glutamine synthetase and rubisco. 19872900091
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
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
the reaction of cytochromes c and c2 with the rhodospirillum rubrum reaction center involves the heme crevice domain.in 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
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
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
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
similarities between soluble inorganic pyrophosphatase from yeast and some nucleotide-binding polypeptides. 19873037828
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 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
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
distance between two active-site lysines of ribulose bisphosphate carboxylase from rhodospirillum rubrum.in the absence of a three-dimensional structure of ribulose-bisphosphate carboxylase/oxygenase [3-phospho-d-glycerate carboxy-lyase(dimerizing), ec 4.1.1.39], 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
new crystal forms of ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum.three crystal forms of the dimeric form of the enzyme ribulose-1,5-bisphosphate carboxylase from the photosynthetic bacterium rhodospirillum rubrum have been obtained from the gene product expressed in escherichia coli. form a crystals formed from the quaternary complex comprising enzyme-activator carbamate-mg2+-2'-carboxyarabinitol-1,5-bisphosphate are shown here to be devoid of ligands. in contrast, crystals of the quaternary complex formed with the hexadecameric l8s8 enzyme from spinach conta ...19863959081
methods of physical labels--a combined approach to the study of microstructure and dynamics in biological systems.the physical principles of several new approaches to the investigation of biological and model systems are discussed, including versions of the spin label method based on relaxation measurements, and also the methods of triplet, mössbauer, electron-scattering and radical-pair labels and probes. it is shown that all these methods make it possible to investigate molecular mobility of the medium with the correlation frequencies tau c-1 = 10(-3) -10(11) s-1, to measure the rate constants of collisio ...19863080515
regulation of nitrogenase activity by ammonium chloride in azospirillum spp.ammonium chloride (greater than or equal to 0.05 mm) effectively and reversibly inhibited the nitrogenase activity of azospirillum brasilense, azospirillum lipoferum and azospirillum amazonense. the glutamine synthetase inhibitor l-methionine-dl- sulfoximine abolished this "switch-off" in a. lipoferum and a. brasilense, but not in a. amazonense. azaserine, an inhibitor of glutamate synthase, inhibited nitrogenase activity itself. this provides further evidence for glutamine as a metabolite of re ...19863081492
studies on the activating enzyme for iron protein of nitrogenase from rhodospirillum rubrum.removal of adp-ribose from the iron protein of nitrogenase by activating enzyme resulted in the activation of the inactive iron protein. a radioassay that directly measured the initial velocity of the activation was developed using iron protein radiolabeled with either [8-3h]- or [g-32p]adp-ribose. the release of radiolabeled adp-ribose by activating enzyme was linearly correlated with the increase in the specific activity of the iron protein as measured by acetylene reduction. both atp and mncl ...19863082874
a reconstruction of the gene for ribulose bisphosphate carboxylase from rhodospirillum rubrum that expresses the authentic enzyme in escherichia coli.escherichia coli plasmid prr36, which expresses rhodospirillum rubrum ribulose bisphosphate carboxylase/oxygenase (ec 4.1.1.39) as a fusion protein [nargang et al., mol. gen. genet. 193 (1984) 220-224], was used to construct a new clone of the carboxylase gene (rbc) whose expression product is the wild-type enzyme. this construction entailed removing all lacz-coding sequences and a portion of the 5'-noncoding leader of the r. rubrum rbc gene. the highest specific activity of carboxylase was obse ...19863084334
reversible regulation of the nitrogenase iron protein from rhodospirillum rubrum by adp-ribosylation in vitro.nitrogenase activity in the photosynthetic bacterium rhodospirillum rubrum is reversibly regulated by interconversion of the fe protein between a modified and an unmodified form. since the discovery of the activation process in 1976, investigators have been unable to demonstrate the inactivation (modification) reaction in vitro. in this study, nad-dependent modification and concomitant inactivation of the fe protein were demonstrated in crude extracts of r. rubrum. activation of the in vitro-mod ...19863084451
partial purification and characterization of pyruvate, orthophosphate dikinase from rhodospirillum rubrum.we confirmed an earlier report (b. b. buchanan, j. bacteriol. 119:1066-1068, 1974) that the nonsulfur purple photosynthetic bacterium rhodospirillum rubrum contains pyruvate, orthophosphate dikinase (ec 2.7.9.1) activity that is absolutely dependent upon all three substrates by performing enzyme assays in both the forward (phosphoenolpyruvate formation) and reverse (atp formation) directions. of the various carbon sources tested, photoheterotrophic growth on dl-lactate plus bicarbonate proved to ...19863003027
hydrogenases of phototrophic microorganisms.this review surveys recent work done in the laboratory of the author and related laboratories on the properties and possible practical applications of hydrogenases of phototrophic microorganisms. homogeneous hydrogenase preparations were obtained from purple non-sulfur (rhodospirillum rubrum s1, rhodobacter capsulatus b10) and purple sulfur (chromatium vinosum d, thiocapsa roseopersicina bbs) bacteria, and from the green sulfur bacterium chlorobium limicola forma thiosulfatophilum l; highly puri ...19863015244
structure of the b880 holochrome of rhodospirillum rubrum as studied by the radiation inactivation method.chromatophores from photoreaction centerless strain f24 of rhodospirillum rubrum were subjected to different doses of gamma radiation. target theory was applied to the induced decay of the b880 holochrome pigments as analyzed by absorption spectroscopy of the membranes and of organic solvent extracts. destruction of bacteriochlorophyll is associated with a target size of 7 kda. this indicates that each one of the two different 6-kda holochrome polypeptides binds one molecule of this pigment. the ...19863081500
n-terminal amino acid sequence of cytochrome c-552 from nitrosomonas europaea.nitrosomonas europaea is an ammonia-oxidizing bacterium which contains multiple c-type cytochromes. few of these components have been assigned physiological roles, but on the basis of molecular weight and redox potential cytochrome c-552 has been considered to be an analogue of the mitochondrial cytochrome-c family of proteins. we present the n-terminal amino acid sequence (47 residues) of cytochrome c-552 and show that this protein is most closely related to the group of small cytochrome-c comp ...19863004498
molecular cloning and sequence of the b880 holochrome gene from rhodospirillum rubrum.restriction fragments of genomic rhodospirillum rubrum dna were selected according to size by electrophoresis followed by hybridization with [32p]mrna encoding the two b880 holochrome polypeptides. the fragments were cloned into escherchia coli c600 with plasmid pbr327 as a vector. the clones were selected by colony hybridization with 32p-holochrome-mrna and counterselected by hybridization with rs. rubrum ribosomal rna, a minor contaminant of the mrna preparation. chimeric plasmid prr22 was sho ...19863001063
kinetics of electron transfer between cytochromes c' and the semiquinones of free flavin and clostridial flavodoxin.rate constants have been measured for the reactions of a series of high-spin cytochromes c' and their low-spin homologues (cytochromes c-554 and c-556) with the semiquinones of free flavins and flavodoxin. these cytochromes are approximately 3 times more reactive with lumiflavin and riboflavin semiquinones than are the c-type cytochromes that are homologous to mitochondrial cytochrome c. we attribute this to the greater solvent exposure of the heme in the c'-type cytochromes. in marked contrast, ...19863008829
ligand-controlled dissociation of chromatium vinosum cytochrome c'.carbon monoxide binding to chromatium vinosum ferrocytochrome c' has been studied by high-precision equilibrium methods. in contrast to the co binding properties of rhodospirillum molischianum cytochrome c' [doyle, m. l., weber, p. c., & gill, s. j. (1985) biochemistry 24, 1987-1991], co binding to c. vinosum cytochrome c' is found to be unusual in the following ways. the binding curve is found to be cooperative with typical hill coefficients equal to 1.25. the shape of the binding curve is asym ...19863013306
substrate specificity and regulation of the maize (zea mays) leaf adp: protein phosphotransferase catalysing phosphorylation/inactivation of pyruvate, orthophosphate dikinase.the protein substrate specificity of the maize (zea mays) leaf adp: protein phosphotransferase (regulatory protein, rp) was studied in terms of its relative ability to inactivate/phosphorylate pyruvate, orthophosphate dikinase from zea mays and the non-sulphur purple photosynthetic bacterium rhodospirillum rubrum. the dimeric bacterial dikinase was inactivated by the maize leaf rp via phosphorylation, with a stoichiometry of approximately 1 mol of phosphate incorporated/mol of 92.7-kda protomer. ...19863019319
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
nonessentiality of histidine 291 of rhodospirillum rubrum ribulose-bisphosphate carboxylase/oxygenase as determined by site-directed mutagenesis.chemical modification of spinach ribulosebisphosphate carboxylase/oxygenase by diethyl pyrocarbonate led to the conclusion that his-298 is an essential active-site residue (igarashi, y., mcfadden, b. a., and el-gul, t. (1985) biochemistry 24, 3957-3962). from the ph dependence of inactivation, the pka of his-298 was observed to be approximately 6.8, and it was suggested that this histidine might be the essential base that initiates catalysis (paech, c. (1985) biochemistry 24, 3194-3199). to expl ...19863090029
purple-bacterial light-harvesting complexes. 19863082693
orthophosphate-pyrophosphate exchange catalyzed by soluble and membrane-bound inorganic pyrophosphatases. role of h+ gradient.a comparative study of the orthophosphate-pyrophosphate exchange reaction catalyzed by the soluble pyrophosphatase from baker's yeast and by the membrane-bound pyrophosphatase of rhodospirillum rubrum chromatophores was performed. in both systems the rate of exchange increased when the ph of the medium was raised from 6.0 to 7.8 and when the mgcl2 concentration was raised from 0.1 mm to 20 mm. for the yeast pyrophosphatase the exchange rates measured at different ph values and in the presence of ...19863015606
a novel fad-protein that allows effective reduction of methyl viologen by nadh (nadh-methyl viologen reductase) from photosynthetic bacterium, rhodospirillum rubrum: purification and characterization.it was found that the cytoplasm of light-grown cells of rhodospirillum rubrum could catalyze the reduction of methyl viologen (mv) (em, 7 = -0.44 v) by nadh and nadph. in the present study, the enzyme capable of catalyzing mv reduction by nadh (nadh-mv reductase) was purified 1,500-fold from an extract of cells with a yield of 4.4%. the purification procedure comprised (nh4)2so4 fractionation, and chromatographies on sepharose cl-6b, deae-sepharose cl-6b, phenyl-sepharose cl-4b, blue-cellulofine ...19863084461
cell-cycle-specific oscillation in the composition of chromatophore membrane in rhodospirillum rubrum.synchrony in phototrophic cultures of rhodospirillum rubrum was induced by stationary-phase cycling or by alterations in light intensity. intracytoplasmic chromatophore membranes were prepared by differential centrifugation. analysis of the composition of chromatophores obtained from cells at different times indicated that the protein/bacteriochlorophyll a ratio was constant throughout the cell cycle but that the protein/phospholipid ratio oscillated. this cell-cycle-dependent fluctuation in chr ...19863086290
nanosecond fluorescence from chromatophores of rhodopseudomonas sphaeroides and rhodospirillum rubrum.single-photon counting techniques were used to measure the fluorescence decay from rhodopseudomonas sphaeroides and rhodospirillum rubrum chromatophores after excitation with a 25-ps, 600-nm laser pulse. electron transfer was blocked beyond the initial radical-pair state (pf) by chemical reduction of the quinone that serves as the next electron acceptor. under these conditions, the fluorescence decays with multiphasic kinetics and at least three exponential decay components are required to descr ...19863087422
immunocytochemical ultrastructural analysis of chromatophore membrane formation in rhodospirillum rubrum.an immunocytochemical ultrastructural study of rhodospirillum rubrum cultured under semiaerobic conditions was conducted to correlate the localization of functional components with membrane formation. r. rubrum is a facultatively phototrophic organism. under reduced oxygen, this bacterium forms an intracytoplasmic chromatophore membrane that is the site of the photosynthetic apparatus. immunogold techniques were used to localize intracellular protein antigens associated with the photosynthetic a ...19863087967
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
crystallization and preliminary analysis of crystals of high potential iron-sulfur protein from rhodospirillum tenue.large single crystals of the high potential iron-sulfur protein isolated from rhodospirillum tenue strain 3761 have been obtained. they belong to the space group p2(1) with unit cell dimensions of a = 36.7 a, b = 52.6 a, c = 27.6 a, and beta = 90.8 degrees. there are two molecules in the asymmetric unit. based on oscillation photographs, the crystals diffract to at least 1.6 a resolution. they are stable in the x-ray beam and appear suitable for a high resolution x-ray structure analysis.19863949809
structural studies of rubisco from tobacco.an 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
role of water in processes of energy transduction: ca2+-transport atpase and inorganic pyrophosphatase.after the proposal of the chemiosmotic theory by mitchell (1966, 1979) it has been recognized that different membrane-bound enzymes are able to use the energy derived from ionic gradients for the synthesis of atp. these include the f1-atpases of mitochondria and chloroplasts, the ca2+-dependent atpase of sarcoplasmic reticulum and the (na+,k+)-atpase of plasma membrane. in these systems the process of energy transduction is fully reversible. the enzyme can use the energy derived from the hydroly ...19852428374
isolation and partial characterization of the messenger rna encoding the b880 holochrome protein of rhodospirillum rubrum.the b880 holochrome messenger rna was extracted from cultures of the photosynthetic bacterium rhodospirillum rubrum. it was purified by chromatography on sepharose 4b followed by sucrose density gradient centrifugation. the purified fractions were shown to program an escherichia coli cell-free system into synthesizing both the alpha and the beta polypeptides of the holochrome. the translation products were identified by immunoprecipitation with specific antibodies raised against these polypeptid ...19852416565
properties and regulation of glutamine synthetase from rhodospirillum rubrum.glutamine synthetase from rhodospirillum rubrum was purified and characterized with respect to its ph optimum and the effect of mg2+ on its active and inactive forms. both adenine and phosphorus were incorporated into the inactive form of the enzyme, indicating covalent modification by amp. the modification could not be removed by phosphodiesterase. evidence for regulation of the enzyme by oxidation was obtained. extracts from oxygen-treated cells had lower specific activities than did extracts ...19852857158
purification and properties of the heat-released nucleotide-modifying group from the inactive iron protein of nitrogenase from rhodospirillum rubrum.nitrogenase in rhodospirillum rubrum is regulated in vivo by the covalent modification of the fe protein. this paper reports the isolation, purification, and properties of the modifying group that has been heat released from the fe protein. the molecule is isolated from the heated mixture by binding to a boronate affinity column. purification is achieved on an ion-exchange high-performance liquid chromatography column. structural properties of the molecule have been investigated by using proton ...19853922413
the light-harvesting polypeptides of rhodopseudomonas viridis. the complete amino-acid sequences of b1015-alpha, b1015-beta and b1015-gamma.three low molecular mass polypeptides have been isolated by using the technique of organic solvent extraction of thylakoid membranes or whole cells from rhodopseudomonas viridis. their primary structures were determined by long liquid phase sequencer runs, combined with the isolation and sequence analysis of the c-terminal o-iodosobenzoic acid fragment and carboxypeptidase degradation. the polypeptide which consists of 58 amino-acids and is 46% homologous to the antenna polypeptide b880-alpha fr ...19853890891
partition kinetics of ribulose-1,5-bisphosphate carboxylase from rhodospirillum rubrum.when the enzymatically generated intermediate 2-carboxy-3-keto-d-arabinitol-1,5-bisphosphate (ii) was used as a substrate with fresh enzyme, 70% reacted to produce 3-phosphoglycerate (3pga). when a reaction mixture of enzyme plus [1-32p]ribulose 1,5-bisphosphate (rubp) was quenched in the steady state with the tightly bound inhibitor 2-carboxyarabinitol-1,5-bisphosphate, 30% of the enzyme-bound species was released as 3pga and 70% as rubp. the major source for this partition was the ternary subs ...19853918036
crystallization of the activated ternary complex of ribulose-1,5-bisphosphate carboxylase-oxygenase isolated from rhodospirillum rubrum and from an escherichia coli clone.ribulose-1,5-bisphosphate carboxylase-oxygenase was purified from the photosynthetic bacterium rhodospirillum rubrum as well as from an escherichia coli clone overproducing the enzyme. although the latter enzyme contains 25 additional amino acid residues at the n terminus, both preparations yielded isomorphous tetragonal, bipyramidal crystals of the ternary complex of the enzyme with co2 and mg2+. crystallization is sensitive to variation in ph and to the addition of the transition state analog, ...19853932659
regulation of nitrogen fixation in rhodospirillum rubrum grown under dark, fermentative conditions.rhodospirillum rubrum was shown to grow fermentatively on fructose with n2 as a nitrogen source. the nitrogenase activity of these cells was regulated by the nh4+ switch-off/switch-on mechanism in a manner identical to that for photosynthetically grown cells. in vitro, the inactive nitrogenase fe protein from fermenting cells was reactivated by an endogenous membrane-bound, mn2+-dependent activating enzyme that was interchangeable with the activating enzyme isolated from photosynthetic membranes ...19853922950
comparative efficiency of primary light conversion in photosynthetic bacteria rhodospirillum rubrum and rhodopseudomonas viridis. 19853939722
the mechanism of the c-13(3) esterification step in the biosynthesis of bacteriochlorophyll a.5-aminolaevulinate labelled with 18o at its c-1 carboxy oxygen atoms was prepared and incorporated into bacteriochlorophyll aphytyl of rhodopseudomonas sphaeroides and bacteriochlorophyll ageranylgeranyl of rhodospirillum rubrum. the biosynthetic samples of the bacteriochlorophylls were separately processed to obtain their isoprenyl alcohol components from the c-17(3) ester linkages and methanol from the c-13(3) methoxycarbonyl group. methods were developed for the quantification of the isotopic ...19854018085
evidence of tyrosine kinase activity in the photosynthetic bacterium rhodospirillum rubrum.the photosynthetic bacterium rohodospirillum rubrum evidenced tyrosine protein phosphorylation under photoautotrophic conditions in the presence of [32p]pi. the stability to alkaline treatment of the [32p] bound to the cell-free extract proteins suggested that tyrosine residues were carrying the labelling. one- and two-dimensional high voltage paper electrophoresis analysis revealed that such extracts do contain [32p]-phosphotyrosine residues. furthermore, the association of alkali stable [32p] ...19853919714
transcription of rhodospirillum rubrum atp operon.the photosynthetic non-sulphur bacterium rhodospirillum rubrum contains a cluster of five genes encoding the subunits of f1-atpase [falk, hampe & walker (1985) biochem. j. 228, 391-407]. transcription of these genes has been studied by two methods, transcriptional mapping with s1 nuclease and primer extension analysis. thereby a 5'-end in rna derived from this region has been demonstrated at a guanine residue 236 bases before the initiation codon of the gene for the delta-subunit, the first in t ...19852864916
enzymatic method for continuous monitoring of inorganic pyrophosphate synthesis.a sensitive method for the analysis of inorganic pyrophosphate (ppi) which utilizes the enzymes atp sulfurylase and firefly luciferase is described. the assay is based on continuous monitoring of the atp formed in the atp sulfurylase reaction using purified firefly luciferase. the assay can be completed in less than 2 s and is not affected by inorganic phosphate. the method has been used for continuous monitoring of formation of ppi in rhodospirillum rubrum chromatophores. the assay is extremely ...19853006540
structure of ferricytochrome c' from rhodospirillum rubrum at 6 a resolution.the structure of a ferricytochrome c' extracted from rhodospirillum rubrum has been determined at 6 a resolution by the x-ray crystallographic method. the crystals, obtained by dialyzing the protein solution against polyethylene glycol 4000, belong to the hexagonal space group p6(1). two heavy atom derivatives were obtained by soaking the native crystals in k2ptcl6 and ch3hgcl solution. the phases calculated by the multiple isomorphous replacement method gave an overall figure of merit of 0.90 a ...19852995330
nitrous oxide reduction by members of the family rhodospirillaceae and the nitrous oxide reductase of rhodopseudomonas capsulata.after growth in the absence of nitrogenous oxides under anaerobic phototrophic conditions, several strains of rhodopseudomonas capsulata were shown to possess a nitrous oxide reductase activity. the enzyme responsible for this activity had a periplasmic location and resembled a nitrous oxide reductase purified from pseudomonas perfectomarinus. electron flow to nitrous oxide reductase was coupled to generation of a membrane potential and inhibited by rotenone but not antimycin. it is suggested th ...19852997133
in vivo interaction between nitrogenase molybdenum-iron protein and membrane in azotobacter vinelandii and rhodospirillum rubrum.oriented whole cell multilayers of azotobacter vinelandii and rhodospirillum rubrum were analyzed by electron spin resonance (esr) spectroscopy to detect possible structural associations between nitrogenase molybdenum-iron (mofe) protein and cytoplasmic or intracytoplasmic membrane. initially, protocols were designed to obtain strong molybdenum-iron protein esr signals in whole cell samples of each organism. then, two-dimensional orientation of whole cell membranes was demonstrated in whole cell ...19852981550
structure of ferricytochrome c' from rhodospirillum molischianum at 1.67 a resolution.the structure of ferricytochrome c' from rhodospirillum molischianum has been crystallographically refined to 1.67 a resolution using a combination of reciprocal space and restrained least-squares refinement methods. the final crystallographic r-factor for 30,533 reflections measured with i greater than sigma (i) between infinity and 1.67 a is 0.188. the final model incorporates 1944 unique protein atoms (of a total of 1972) together with 194 bound solvent molecules. the structure has been analy ...19853005592
evidence that the mg-dependent low-affinity binding site for atp and pi demonstrated on the isolated beta subunit of the f0.f1 atp synthase is a catalytic site.binding sites for one pi and two atp or adp molecules have been identified on the isolated, reconstitutively active beta subunit from the rhodospirillum rubrum f0.f1 atp synthase. chemical modification of this beta subunit by the histidine reagent diethyl pyrocarbonate or by the carboxyl group reagent woodword's reagent k results in complete inhibition of pi binding to beta. the same reagents inhibit the binding of atp to a mg-dependent low-affinity site but not to a mg-independent high-affinity ...19852858854
nucleotide sequence of the rhodospirillum rubrum atp operon.the nucleotide sequence was determined of a 8775-base-pair region of dna cloned from the photosynthetic non-sulphur bacterium rhodospirillum rubrum. it contains a cluster of five genes encoding f1-atpase subunits. the genes are arranged in the same order as f1 genes in the escherichia coli unc operon. however, as in the related organism rhodopseudomonas blastica, neither genes for components of f0, the membrane sector of atp synthase, nor a homologue of the e. coli unci gene are associated with ...19852861810
atp synthesis and hydrolysis by a hybrid system reconstituted from the beta-subunit of escherichia coli f1-atpase and beta-less chromatophores of rhodospirillum rubrum.photophosphorylation and atpase activities were restored to beta-less rhodospirillum rubrum chromatophores by their reconstitution with purified beta-subunits of either r. rubrum f1-atpase (rr beta) or escherichia coli f1-atpase (ec beta). in the homologous reconstituted system both activities were restored to the same extent, whereas in the hybrid system atp synthesis was restored to about 10% when the hydrolysis was restored to 200%. this difference in rates of synthesis and hydrolysis was not ...19852864345
stoichiometry determination for carbon monoxide binding to rhodospirillum molischianum cytochrome c'.the stoichiometry of co ligation to the dimer heme protein rhodospirillum molischianum cytochrome c' is determined. we have recently measured the enthalpy change of co ligation to this molecule by the van't hoff method and found the value of -10.7 +/- 1.2 kcal/mol co (aqueous) (doyle, m. l., weber, p. c., and gill, s. j. (1985) biochemistry 24, 1987-1991). in the present paper the enthalpy change of co ligation, measured directly by titration calorimetry, is found to be -9.5 +/- 0.2 kcal/mol hem ...19852991251
synthesis of pyrophosphate by chromatophores of rhodospirillum rubrum in the light and by soluble yeast inorganic pyrophosphatase in water-organic solvent mixtures.chromatophores of rhodospirillum rubrum contain a membrane-bound pyrophosphatase that synthesizes pyrophosphate when an electrochemical h+ gradient is formed across the chromatophore membrane upon illumination. in this report it is shown that mgcl2 and pi have different effects on the synthesis of pyrophosphate in the light depending on whether initial velocities or steady-state levels are examined. when the water activity of the medium is reduced by the addition of organic solvents, soluble yea ...19852995032
the phosphate-pyrophosphate exchange and hydrolytic reactions of the membrane-bound pyrophosphatase of rhodospirillum rubrum: effects of mg2+, phosphate, and pyrophosphate.the relation that exists 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 added mg2+. optimal rates of hydrolysis were attained at 1 mm mg2+ with 0.67 mm pyrophosphate; the rate od hydrolysis correlated with the concentration of mg-pyrophosphate, which indicated that the latter was the substrate for hydrolysis. the pi-ppi excha ...19852982324
carbon monoxide binding to rhodospirillum molischianum ferrocytochrome c'.reversible carbon monoxide binding has been used to examine the structural and functional properties of reduced rhodospirillum molischianum cytochrome c'. the symmetrical dimer is found to bind co in a noncooperative manner, indicating that the heme sites function independently and with identical carbon monoxide affinity. the enthalpy change of binding co (aqueous) to r. molischianum ferrocytochrome c' is determined to be -11 kcal/mol of co, which is comparable to the heat of co binding to other ...19852990547
site-specific mutagenesis of ribulose-1,5-bisphosphate carboxylase/oxygenase. evidence that carbamate formation at lys 191 is required for catalytic activity.site-specific mutagenesis of a cloned gene for ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum was used to examine the functional significance of carbamate activation. lysine 191, the residue involved in carbamate formation, was replaced with a glutamate in order to mimic the anionic nature of the carbamate. the resulting enzyme was capable of binding the six-carbon transition state analog carboxyarabinitol bisphosphate, but completely lacked catalytic activity. in con ...19852991249
binding of cytochrome c2 to the isolated reaction center of rhodospirillum rubrum involves the "backside" of cytochrome c2.lys 109, lys 112 and glu 1 of cytochrome c2 from rhodospirillum rubrum g-9 are about 4-fold less reactive towards acetic anhydride when cytochrome c2 is bound to the isolated photosynthetic reaction center from the same organism. the three shielded residues are clustered together on the "backside" of cytochrome c2. this contrasts with mitochondrial cytochrome c where "frontside" lysines are protected by different physiological electron transfer partners.19852985069
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