Publications

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.	1988	3129411
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 ...	1988	3131324
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 ...	1988	2829176
the structural genes coding for the l and m subunits of rhodospirillum rubrum photoreaction center.	in rhodospirillum rubrum, pufl, and pufm, the structural genes coding for the photoreaction center l and m polypeptides, are comprised respectively of 831 and 921 nucleotides. they are separated by a stretch of 12 nucleotides between the taa stop codon of pufl and the first base of the atg initiation codon of pufm. the predicted amino acid sequence of the l and m polypeptides, respectively, contain 275 and 305 residues with corresponding molecular weights of 30,473 and 33,978. their sequences ar ...	1988	2836391
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 ...	1988	2834719
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 ...	1988	2896020
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 ...	1988	2842301
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 ...	1988	2896501
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 ...	1988	2902844
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 ...	1988	2837275
properties of a tn5 insertion mutant defective in the structural gene (frua) of the fructose-specific phosphotransferase system of rhodobacter capsulatus and cloning of the fru regulon.	in photosynthetic bacteria such as members of the genera rhodospirillum, rhodopseudomonas, and rhodobacter a single sugar, fructose, is transported by the phosphotransferase system-catalyzed group translocation mechanism. previous studies indicated that syntheses of the three fructose catabolic enzymes, the integral membrane enzyme ii, the peripheral membrane enzyme i, and the soluble fructose-1-phosphate kinase, are coordinately induced. to characterize the genetic apparatus encoding these enzy ...	1988	2832374
determination of the functional homology of beta subunits isolated from various f1-atpase complexes: their role in catalysis and coupled proton-translocation.		1988	2458598
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 ...	1987	2820990
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 ...	1987	2820485
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 ...	1987	2820933
some evolutionary relationships of the primary biological catalysts glutamine synthetase and rubisco.		1987	2900091
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.	1987	2823802
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 ...	1987	3125156
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 ...	1987	3119577
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, ...	1987	3327916
malate dehydrogenase in phototrophic purple bacteria: purification, molecular weight, and quaternary structure.	the citric acid cycle enzyme malate dehydrogenase was purified to homogeneity from the nonsulfur purple bacteria rhodobacter capsulatus, rhodospirillum rubrum, rhodomicrobium vannielii, and rhodocyclus purpureus. malate dehydrogenase was purified from each species by either a single- or a two-step protocol: triazine dye affinity chromatography was the key step in purification of malate dehydrogenase in all cases. purification of malate dehydrogenase resulted in a 130- to 240-fold increase in mal ...	1987	3114237
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 ...	1987	3117111
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 ...	1987	3119564
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 ...	1987	3119570
structural and evolutionary aspects of the key enzymes in photorespiration; rubisco and glycolate oxidase.		1987	3135980
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 ...	1987	3036517
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 ...	1987	3029096
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 ...	1987	3579306
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 ...	1987	3040698
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 ...	1987	3040700
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 ...	1987	2886121
similarities between soluble inorganic pyrophosphatase from yeast and some nucleotide-binding polypeptides.		1987	3037828
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 ...	1987	3038904
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 ...	1987	2885306
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 ...	1987	2878918
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 ...	1987	2883008
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 ...	1987	2889424
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 ...	1987	3102487
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 ...	1987	3032020
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 ...	1987	3032236
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 ...	1987	3040083
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 ...	1987	3120806
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 ...	1987	11542078
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 ...	1986	16453738
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 ...	1986	16593786
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 ...	1986	16664941
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 ...	1986	3080515
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, ...	1986	3008829
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 ...	1986	3013306
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 ...	1986	3015606
molecular cloning and sequence of the b880 holochrome gene from rhodospirillum rubrum.	restriction fragments of genomic rhodospirillum rubrum dna were selected according to size by electrophoresis followed by hybridization with [32p]mrna encoding the two b880 holochrome polypeptides. the fragments were cloned into escherchia coli c600 with plasmid pbr327 as a vector. the clones were selected by colony hybridization with 32p-holochrome-mrna and counterselected by hybridization with rs. rubrum ribosomal rna, a minor contaminant of the mrna preparation. chimeric plasmid prr22 was sho ...	1986	3001063
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 ...	1986	3003027
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 ...	1986	3081500
purple-bacterial light-harvesting complexes.		1986	3082693
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 ...	1986	3084334
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 ...	1986	3084451
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 ...	1986	3090029
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 ...	1986	3090034
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 ...	1986	3082874
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 ...	1986	3084461
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 ...	1986	3087967
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 ...	1986	3015244
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. ...	1986	3019319
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 ...	1986	3081492
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 ...	1986	3086290
nanosecond fluorescence from chromatophores of rhodopseudomonas sphaeroides and rhodospirillum rubrum.	single-photon counting techniques were used to measure the fluorescence decay from rhodopseudomonas sphaeroides and rhodospirillum rubrum chromatophores after excitation with a 25-ps, 600-nm laser pulse. electron transfer was blocked beyond the initial radical-pair state (pf) by chemical reduction of the quinone that serves as the next electron acceptor. under these conditions, the fluorescence decays with multiphasic kinetics and at least three exponential decay components are required to descr ...	1986	3087422
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 ...	1986	3004498
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 ...	1986	3090031
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 ...	1986	3092806
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.	1986	3949809
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 ...	1986	3959081
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 ...	1986	2878449
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 ...	1986	2427516
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 ...	1986	2420229
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 ...	1985	2428374
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 ...	1985	2416565
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 ...	1985	2857158
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 ...	1985	2991249
lattice mobility and anomalous temperature factor behaviour in cytochrome c'.	atomic temperature factors (b-values) obtained from x-ray refinement experiments provide empirical estimates of protein mobility that have been correlated with both theoretical simulations of protein dynamics and experimental studies of antibody reactivity. the comparison of b-values with protein solution properties requires adjustment of the apparent atomic mobilities to compensate for the effects of the crystal environment. here we compare crystallographically independent subunits of the dimer ...	1985	2989701
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 ...	1985	2864916
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 ...	1985	2991251
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 ...	1985	2990547
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 ...	1985	2982324
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 ...	1985	2861810
dna-directed in vitro synthesis and assembly of the form ii d-ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodopseudomonas sphaeroides.	a biochemical analysis of the in vitro assembly of the form ii ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodopseudomonas sphaeroides after transcription and translation from cloned dna is presented. the predominant enzymatically active oligomeric forms of the in vitro-synthesized and -assembled ribulose-1,5-bisphosphate carboxylase are tetramers and hexamers. assembly of the monomeric subunits to form active enzyme appears to be dependent on the presence of a minimum number of subuni ...	1985	3918003
characterization of an active-site peptide modified by glyoxylate and pyridoxal phosphate from spinach ribulosebisphosphate carboxylase/oxygenase.	activated ribulosebisphosphate carboxylase/oxygenase from spinach was treated with glyoxylate plus or minus the transition-state analog, carboxyarabinitol bisphosphate, or the inactive enzyme with pyridoxal phosphate plus or minus the substrate, ribulose bisphosphate. covalently modified adducts with glyoxylate or pyridoxal phosphate were formed following reduction with sodium borohydride. the derivatized enzymes were carboxymethylated and digested with trypsin; the labeled peptides which were u ...	1985	3860189
helix movements and the reconstruction of the haem pocket during the evolution of the cytochrome c family.	analysis of cytochromes c (tuna), c2 (rhodospirillum rubrum), c550 (paracoccus denitrificans) and c551 (pseudomonas aeruginosa) shows that they contain 48 residues identifiable as homologous from superposition of the structures. the other 34 to 64 residues are in loops that vary greatly in sequence, length and conformation, or in alpha-helices that are found in only some of the structures. of the 48 homologous residues, 17 are in three segments which pack onto the haem faces. in all four structu ...	1985	2987508
soluble cytochrome composition of the purple phototrophic bacterium, rhodopseudomonas sphaeroides atcc 17023.	a detailed study of the soluble cytochrome composition of rhodopseudomonas sphaeroides (atcc 17023) indicates that there are five c-type cytochromes and one b-type cytochrome present. the molecular weights, heme contents, amino acid compositions, isoelectric points, and oxidation-reduction potentials were determined and the proteins were compared with those from other bacterial sources. cytochromes c2 and c' have previously been well characterized. cytochrome c-551.5 is a diheme protein which ha ...	1985	2986691
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.	1985	2985069
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 ...	1985	2864345
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 ...	1985	3005592
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 ...	1985	3006540
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 ...	1985	2981550
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 ...	1985	2858854
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 ...	1985	2995330
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 ...	1985	2997133
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 ...	1985	2995032
regulation of nitrogenase activity by covalent modification in chromatium vinosum.	nitrogenase in chromatium vinosum was rapidly, but reversibly inhibited by nh4+. activity of the fe protein component of nitrogenase required both mn2+ and activating enzyme. activating enzyme from rhodospirillum rubrum could replace chromatium chromatophores in activating the chromatium fe protein, and conversely, a protein fraction prepared from chromatium chromatophores was effective in activating r. rubrum fe protein. inactive chromatium fe protein contained a peptide covalently modified by ...	1985	3857878
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 ...	1985	4018085
purification and properties of the nitrogenase of azospirillum amazonense.	the nitrogenase of the free-living, microaerobic, n2-fixing bacterium azospirillum amazonense (strain y1) was purified by chromatography on deae-52 cellulose, by heat treatment, and by preparative polyacrylamide gel electrophoresis. the specific nitrogenase activities were 2,400 nmol of c2h4 formed per min per mg of protein for dinitrogenase (mofe protein) and 1,800 nmol of c2h4 formed per min per mg of protein for dinitrogenase reductase (fe protein). the mofe protein was composed of a minimum ...	1985	3864779