TitleAbstractYear(sorted ascending)
intermediates in the ribulose-1,5-bisphosphate carboxylase least two intermediates of the d-ribulose-1,5-bisphosphate carboxylase/oxygenase (ec reaction were liberated in detectable amounts when the functioning enzyme from rhodospirillum rubrum was quenched in acid. using substrate labeled with 32p in c-1, [32p]orthophosphate (pi) was found when the quenched solution was rapidly processed for extraction of pi as the acid molybdate complex. reaction with sodium borohydride under mildly alkaline conditions immediately after acid quenching of ...19846427222
preliminary x-ray diffraction study of ribulose-1,5-bisphosphate carboxylase from rhodospirillum rubrum.crystals from the dimeric enzyme ribulose-1,5-bisphosphate carboxylase of the photosynthetic bacterium rhodospirillum rubrum have been obtained from the gene product expressed in escherichia coli. the crystals are of the quarternary complex comprising enzyme: activator co2 (as a carbamate): mg2+: 2- carboxyarabinitol -1,5-bisphosphate (as a transition state analog). x-ray diffraction photographs show symmetry consistent with space group p4(1)2(1)2 or the corresponding enantiomorphic space group. ...19846427471
complete primary structure of ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum.of the 14 cyanogen bromide fragments derived from rhodospirillum rubrum ribulosebisphosphate carboxylase/oxygenase, four are too large to permit complete sequencing by direct means [f. c. hartman, c. d. stringer, j. omnaas, m. i. donnelly, and b. fraij (1982) arch. biochem. biophys. 219, 422-437]. these have now been digested with proteases, and the resultant peptides have been purified and sequenced, thereby providing the complete sequences of the original fragments. with the determination of t ...19846430239
carbon monoxide dehydrogenase from rhodospirillum rubrum.the carbon monoxide dehydrogenase from the photosynthetic bacterium rhodospirillum rubrum was purified over 600-fold by deae-cellulose chromatography, heat treatment, hydroxylapatite chromatography, and preparative scale gel electrophoresis. in vitro, this enzyme catalyzed a two-electron oxidation of co to form co2 as the product. the reaction was dependent on the addition of an electron acceptor. the enzyme was oxygen labile, heat stable, and resistant to tryptic and chymotryptic digestion. opt ...19846430875
preliminary structural studies of ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum.ribulose-1,5-bisphosphate carboxylase/oxygenase (ec from rhodospirillum rubrum has been crystallized in a form that is suitable for structural studies by x-ray diffraction. the asymmetric unit of the crystal contains one dimeric enzyme molecule of molecular mass 101,000 da. the enzyme was activated prior to crystallization and is presumed to be in the co2-activated state in the crystal. the method of hydrophobicity correlation has been used to compare the amino acid sequence of this mo ...19846432800
the light-harvesting polypeptides of rhodospirillum rubrum. i. the amino-acid sequence of the second light-harvestng polypeptide b 880-beta (b 870-beta) of rhodospirillum rubrum s 1 and the carotenoidless mutant g-9+. carotenoidless mutant g-9+.the light-harvesting complex b 880 from rhodospirillum rubrum s 1 (wild type) and b 870 from the carotenoidless mutant g-9+ was shown to consist mainly of an organic solvent-(chloroform/methanol-) soluble and an organic solvent-insoluble polypeptide. the isolation and separation of these two low-molecular-mass polypeptides (mr 6101 and mr 6079) were achieved by a two-step extraction procedure of chromatophores using in the first step chloroform/methanol containing 0.1m ammonium acetate. followin ...19846434396
the light-harvesting polypeptides of rhodospirillum rubrum. ii. localisation of the amino-terminal regions of the light-harvesting polypeptides b 870-alpha and b 870-beta and the reaction-centre subunit l at the cytoplasmic side of the photosynthetic membrane of rhodospirillum rubrum g-9+.the unspecific proteinase k and the specific proteases alpha-chymotrypsin, trypsin and s. aureus v 8 protease were used in order to determine the orientation of the polypeptides b 870-alpha and b 870-beta from the major antenna complex b 870 of rs. rubrum g-9+ within the chromatophore membrane (inside-out vesicle). although b 870-alpha exhibits cleavable peptide bonds, treatment with specific proteases yielded splitting only in b 870-beta within the n-terminal region. in the case of proteinase k ...19846434397
plasmidless, photosynthetically incompetent mutants of rhodospirillum rubrum.ethyl methanesulfonate rendered a high percentage of rhodospirillum rubrum cells plasmidless and photosynthetically incompetent (kuhl et al., j. bacteriol. 156:737-742, 1983). by probing restriction endonuclease-digested chromosomal dna from these plasmidless strains with 32p-labeled r. rubrum plasmid dna, we showed that no homology exists between the plasmid and the chromosomal dna of the mutant. loss of the plasmid in all the nonphotosynthetic isolates was accompanied by the synthesis of spiri ...19846434514
nature and location of amide-bound (r)-3-acyloxyacyl groups in lipid a of lipopolysaccharides from various gram-negative has previously been demonstrated [eur. j. biochem. 124, 191-198 (1982) and 137, 15-22 (1983)] that the lipid a component of salmonella and proteus lipopolysaccharides contains amide-linked (r)-3-acyloxyacyl residues. in the present study lipid a of other gram-negative bacteria was analysed for the presence of amide-bound 3-acyloxyacyl residues. it was found that such residues are constituents of all lipid a tested (agrobacterium tumefaciens, chromobacterium violaceum, pseudomonas aeruginosa, ...19846437812
the mechanism of the attachment of esterifying alcohol in bacteriochlorophyll a biosynthesis.the mechanism through which the c-17(3) carboxy group of bacteriochlorophyllide a is esterified to produce bacteriochlorophyll aphytyl of rhodopseudomonas spheroides and bacteriochlorophyll ageranylgeranyl of rhodospirillum rubrum was studied by using 5-aminolaevulinate labelled with 18o at its c-1 carboxy oxygen atoms. the latter species was prepared by an exchange reaction in which 5-aminolaevulinate hydrochloride was heated in h218o in an autoclave. a method for the determination of the 18o c ...19846439193
the distribution of microsomal glutathione transferase among different organelles, different organs, and different the present study we have used both enzyme assay with 1-chloro-2,4-dinitrobenzene as substrate and immunochemical quantitation to examine the distribution of microsomal glutathione transferase in different organelles, in different organs, and in different organisms. this enzyme was found to constitute 3% and 5%, respectively, of the total protein recovered in the microsomal and outer mitochondrial membrane fractions from rat liver. microsomal glutathione transferase present in other subcellul ...19846439207
purification and properties of the activating enzyme for iron protein of nitrogenase from the photosynthetic bacterium rhodospirillum rubrum.the oxygen-labile, activating enzyme for iron protein from the photosynthetic bacterium, rhodospirillum rubrum, was purified 11,800-fold using a combination of chromatophore washing, de52-cellulose chromatography, hydroxylapatite chromatography, reactive red-120 cross-linked agarose chromatography, reactive red-120 cross-linked agarose chromatography, and sephadex g-75 gel filtration. activating enzyme appeared homogeneous on silver-stained sodium dodecyl sulfate-polyacrylamide gels, and the sta ...19846439722
[effect of dehydration on the primary picosecond stages of charge separation in rhodospirillum rubrum].effects of dehydration on the quantum yield of charge separation in the reaction centres, fluorescence and nanosecond recombination luminescence in r. rubrum chromatophores have been investigated. it has been shown that dehydration results in more than a 10 times decrease in the quantum efficiency of photosynthesis. besides, photoinduced fluorescence changes practically disappear in dehydrated samples and the parameters of nanosecond luminescence substantially change. these observations indicate ...19846441114
adenine nucleotide levels in rhodospirillum rubrum during switch-off of whole-cell nitrogenase activity.adenine nucleotide pools were measured in rhodospirillum rubrum cultures that contained nitrogenase. the average energy charge [([atp] + 1/2[adp])/([atp] + [adp] + [amp])] was found to be 0.66 and 0.62 in glutamate-grown and n-limited cultures respectively. treatment of glutamate-grown cells with darkness, ammonia, glutamine, carbonyl cyanide m-chlorophenylhydrazone, or phenazine methosulphate resulted in perturbations in the adenine nucleotide pools, and led to loss of whole-cell nitrogenase ac ...19846441571
x-ray diffraction studies on chromatophore membrane from photosynthetic bacteria. iii. basic structure of the photosynthetic unit and its relation to other bacteriochlorophyll forms.we have performed x-ray diffraction studies on photosynthetic units of rhodospirillum rubrum and solubilized *b800 + b890 complex from chromatophores of chromatium vinosum, to investigate the homology of their molecular structures. the native chromatophores of chromatium vinosum, which contain other bacteriochlorophyll forms, were examined by an x-ray diffraction technique, in order to assess the interactions between the complexes as well as the molecular structures of the bacteriochlorophyll fo ...19846442292
molecular cloning of the phosphoenolpyruvate carboxylase gene, ppc, of escherichia coli.the cole1 hybrid plasmid, plc20-10, carrying the ppc gene and the argecbh gene cluster of escherichia coli k-12, was characterized. the ppc gene coding for phosphoenolpyruvate carboxylase (ec, was subcloned into the plasmid pbr322 to give the plasmids ps2 and ps3. these plasmids carried a 4.4-kb sali segment containing the ppc gene, in both orientations. the specific activity of the enzyme was increased approx. 20-fold by these plasmids. experiments with maxicells harboring ps2 showed ...19846396163
cloning and expression in escherichia coli of the form ii ribulose 1,5-bisphosphate carboxylase/oxygenase gene from rhodopseudomonas sphaeroides.the gene encoding the form ii ribulose 1,5-bisphosphate carboxylase/oxygenase (rubpc/o) from rhodopseudomonas (r.) sphaeroides has been identified on a 3-kb ecori fragment and cloned into a broad-host-range, high-copy-number plasmid, using the gene from rhodospirillum (rs.) rubrum as a hybridization probe. subclones of the gene from r. sphaeroides in pbr322 and puc8 show substantial levels of expression and enzymatic activity in whole cells and crude cell extracts of escherichia coli. this enzym ...19846396166
unusual lipid a types in phototrophic bacteria and related species.photosynthetic bacteria of the rhodospirillaceae family (sulfur-free purple bacteria) possess lipopolysaccharides (lps) that deviate markedly from the salmonella lipopolysaccharides in the chemical makeup of the lipid a component and in their biologic properties. lps of rhodopseudomonas gelatinosa is highly toxic and pyrogenic, while that of rhodospirillum tenue shows cryptic toxicity. two lps types are completely non-toxic. the rhodopseudomonas sphaeroides lipid a has the same backbone as that ...19846474014
protein on the cell surface of the moderately halophilic phototrophic bacterium rhodospirillum salexigens.a cell surface protein (mr 68,000) of the moderately but obligately halophilic phototrophic bacterium rhodospirillum salexigens was identified by two independent methods: first, by labeling the cell surface with radioactive iodine and lactoperoxidase, and second, by washing cells in 30% sucrose to remove proteins attached to the cell surface by ionic bonds. the identified protein very likely represents the outermost layer of the cell envelope of r. salexigens as observed by electron microscopy. ...19846480555
[generic interrelations of purple bacteria in the genus rhodopseudomonas].the technique of dna--dna hybridization was used to study relations offween purple nonsulfur bacteria (the family rhodospirillaceae). the level of homologies with rhodopseudomonas sphaeroides 8259 was nearly the same for different species (8-17%) in the genus rhodopseudomonas under the conditions optimal for hybridization. the same level of homologies was found for the dna of rhodospirillum rubrum, a species belonging to another genus of purple nonsulfur bacteria (13%). rhodomicrobium vannielli ...19846610816
nitrogen fixation and nitrogenase activities in members of the family rhodospirillaceae.strains of all 18 species of the family rhodospirillaceae (nonsulfur photosynthetic bacteria) were studied for their comparative nitrogen-fixing abilities. all species, with the exception of rhodocyclus purpureus, were capable of growth with n2 as the sole nitrogen source under photosynthetic (anaerobic) conditions. most rapid growth on n2 was observed in strains of rhodopseudomonas capsulata. within the genus rhodopseudomonas, the species r. capsulata, r. sphaeroides, r. viridis, r. gelatinosa, ...19846581158
oxido-reduction of b800-850 and b880 holochromes isolated from three species of photosynthetic bacteria as studied by electron-paramagnetic resonance and optical spectroscopy.certain redox properties of bacteriochlorophyll alpha were used to probe the structure of several light-harvesting pigment-protein complexes or holochromes. to attribute redox properties unequivocally to a given holochrome, we worked with purified holochromes. we developed purification procedures for the b880 holochromes from rhodospirillum rubrum, rhodopseudomonas sphaeroides and ectothiorhodospira sp. and for the b800-850 holochromes from the latter two species. in all these holochromes, bacte ...19846086349
influence of cyclic amp on photosynthetic development in rhodospirillum rubrum.during o2-free growth in the light and in medium with pyruvate, rhodospirillum rubrum exhibits diauxic growth. the cells first fermented pyruvate and afterwards photometabolized. exogenous cyclic amp acted to prolong the lag period between fermentative and photosynthetic development, as well as to slow the light-dependent growth rate. this observation, and in situ changes in the cyclic amp levels in cells undergoing biphasic growth, suggested that the cyclic nucleotide was involved in photosynth ...19846086589
cytochromes c' in their reaction with ethyl isocyanide.the binding of ethyl isocyanide (eic) to a representative number of cytochromes c' is demonstrated. spectroscopic and equilibrium constants have been measured and compared for the binding of eic to cytochromes c' from the photosynthetic bacteria chromatium vinosum, rhodopseudomonas palustris, rhodospirillum rubrum, and rhodopseudomonas sphaeroides. while the absorption spectra of the eic complexes resemble those of eic complexes of other high-spin hemoproteins, the soret half band widths and ext ...19846087877
a new crystal form and preliminary crystallographic data for ferricytochrome c' from rhodospirillum rubrum.a new crystal form of ferricytochrome c' from the photosynthetic bacteria, rhodospirillum rubrum, has been obtained by dialysing protein solution against polyethylene glycol 4000. the crystals belong to the space group p61 (or its enantiomorph p65) with unit cell dimensions: a = b = 51.63 a and c = 155.39 a. the asymmetric unit contains one dimer molecule of 28,000 molecular weight and the solvent content of the unit cell is approximately 38%.19846090675
electron-transfer reactions of photoreduced flavin analogues with c-type cytochromes: quantitation of steric and electrostatic factors.we have found correlations between rate constants and the difference in redox potential of the reactants for electron-transfer reactions between oxidized cytochromes and either photoproduced riboflavin or flavin mononucleotide (fmn) semiquinones (the latter rate constants extrapolated to infinite ionic strength). the riboflavin-cytochrome rate constants are about 70% of those for reduction by lumiflavin, probably because of steric interference by the ribityl side chain. reduction of cytochromes ...19846093864
[delayed bacteriochlorophyll luminescence and the primary stages of electron transport in photosynthetic reaction centers of purple bacteria].the results of studies of charge separation in photosynthetic reaction centers of purple bacteria are summarized. the findings concerning the sequence of initial steps of the electron transfer and properties of the electron carriers obtained by direct methods of differential optical absorption and esr spectroscopy are compared with the data on the bacteriochlorophyll delayed fluorescence resulting from reversal of charge separation. the data analysis gives an integrated description of the reacti ...19846095028
evaluation of the complexity of charge recombination kinetics in photosynthetic bacteria. 19846095340
electron spin resonance studies of ribulosebisphosphate carboxylase: identification of activator cation ligands.ribulosebisphosphate carboxylase (rubp carboxylase)forms a stable model complex containing stoichiometric amounts of enzyme sites, activator c0(2), divalent activator cation, and the transition-state analogue carboxyarabinitol bisphosphate (cabp). incorporation of mn(2+) in the model complex permits investigation of the environment of the activator cation by electron spin resonance (esr)techniques. measurements at 9 ghz on the mn(2+)-containing complex prepared by using dimeric rhodospirillum ru ...198419725189
kinetic variance of ribulose-1,5-bisphosphate carboxylase/oxygenase isolated from diverse taxonomic sources : ii. analysis by two dual label methods.two dual label methods were used to investigate kinetic variability of ribulose 1,5-bisphosphate (rubp) carboxylase/oxygenase (ec in addition to using [1-(14)c,5-(3)h]rubp (method 1), we describe here the detailed assay with (14)co(2) and [5-(3)h]rubp (method 2), which generates [(3)h,(14)c]3-phosphoglyceric acid and unlabeled (noncontaminating) phosphoglycolate; the carboxylase/oxygenase activity ratio (v(c)/v(o)) is calculated from (3)h/(14)c ratios of substrates and products. v(c)/ ...198416663680
a site-specific mutation within the active site of ribulose-1,5-bisphosphate carboxylase of rhodospirillum vitro mutagenic techniques have generated an asp-->glu substitution at residue 198 adjacent to the carbamate-divalent metal ion binding site of rhodospirillum rubrum ribulose 1,5-bisphosphate carboxylase. a single c-->a nucleotide change in the coding strand created the mutant and introduced a new ecori restriction site on the expression plasmid prr2119. although the carboxylase:oxygenase ratio remained the same, the mutant enzyme had slightly altered kinetic properties. the e.p.r. spectra of ...198416453576
structural studies of the primary donor cation radical p(870) in reaction centers of rhodospirillum rubrum by electron-nuclear double resonance in solution.the light-induced cation radical of the primary electron donor, p(870) (+.), in photosynthetic reaction centers from rhodospirillum rubrum g-9, has been investigated by electron-nuclear double resonance (endor) in liquid aqueous solution. the measured hyperfine coupling constants are assigned to specific molecular positions by partial deuteration. comparison with the bacteriochlorophyll a cation radical shows different reduction factors of the individual coupling constants deviating from the val ...198416593428
the phylogeny of purple bacteria: the alpha subdivision.the technique of oligonucleotide cataloging shows the purple photosynthetic eubacteria to comprise three major subdivisions, temporarily called alpha, beta, and gamma--previously designated groups i-iii by gibson et al. (1979). each subdivision contains a number of non-photosynthetic genera in addition to the photosynthetic ones. the alpha subdivision, the subject of the present report, contains most but not all of the species that fall into the classically defined genera rhodospirillum, rhodo ...198411541974
phylogenetic origins of the plant mitochondrion based on a comparative analysis of 5s ribosomal rna sequences.the complete nucleotide sequences of 5s ribosomal rnas from rhodocyclus gelatinosa, rhodobacter sphaeroides, and pseudomonas cepacia were determined. comparisons of these 5s rna sequences show that rather than being phylogenetically related to one another, the two photosynthetic bacterial 5s rna sequences show that rather than being phylogenetically related to one another, the two photosynthetic bacterial 5s rnas share more sequence and signature homology with the rnas of two nonphotosynthetic ...198511542018
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
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
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
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
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
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
the amino acid sequence of a high-redox-potential ferredoxin from the purple phototrophic bacterium, rhodospirillum tenue strain 2761.the 61-residue amino acid sequence of rhodospirillum tenue, strain 2761, high-redox-potential ferredoxin (hipip) is gtnaamrkafnyqdtakngkcsgcaqfvpgasptaaggckvipgdneiapggycdafivkk. it differs from that of r. tenue strain 3761 by 16 amino acid substitutions plus two single-residue deletions. this 26% sequence difference is similar to that observed among separate species of chromatiaceae such as chromatium vinosum, c. gracile, and thiocapsa roseopersicina, and is suprising because there are no disti ...19854004266
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
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
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
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
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 ...19852986691
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 ...19852987508
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 ...19852989701
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 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
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
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
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 ...19853857878
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 ...19853860189
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 ...19853864779
succinate dehydrogenase in rhodopseudomonas sphaeroides: subunit composition and immunocross-reactivity with other related bacteria.antibodies were raised against the succinate dehydrogenase (sdh) present in the chromatophores of phototrophically grown rhodopseudomonas sphaeroides. crossed immunoelectrophoresis experiments indicated that the sdh present in the cytoplasmic membranes of heterotrophically grown r. sphaeroides is probably the same enzyme observed in the chromatophores. the enzyme was extracted by triton x-100 in a form which consisted of only two subunits (molecular weight, 68,000 and 30,000) and was not associa ...19853874866
large-scale preparation of ribulosebisphosphate carboxylase from a recombinant system in escherichia coli characterized by extreme plasmid ampicillin-resistant, reca- strain of escherichia coli (hb101) harboring the multicopy pbr322 plasmid containing the structural gene for ribulosebisphosphate carboxylase from rhodospirillum rubrum was used to prepare large quantities of the carboxylase protein. this recombinant system was characterized by extreme plasmid instability, which resulted in part from the 1.7-fold faster growth rate of plasmid-free cells and in part from very rapid rates of plasmid segregation. the plasmid-containin ...19853890745
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
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 ...19853918003
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
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
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
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
covalent modification of the iron protein of nitrogenase from rhodospirillum rubrum by adenosine diphosphoribosylation of a specific arginine residue.nitrogenase in rhodospirillum rubrum is inactivated in vivo by the covalent modification of the fe protein with a nucleotide. the preparation of two modified peptides derived from proteolytic digestion of the inactive fe protein is described. the modifying group is shown to be adenosine diphosphoribose, linked through the terminal ribose to a guanidino nitrogen of arginine. the structural features were established by using proton and phosphorus nmr, positive- and negative-ion fast atom bombardme ...19853923473
carbon isotope effect on carboxylation of ribulose bisphosphate catalyzed by ribulosebisphosphate carboxylase from rhodospirillum rubrum.the carbon isotope effect at co2 has been measured in the carboxylation of ribulose 1,5-bisphosphate by the ribulosebisphosphate carboxylase from rhodospirillum rubrum. the isotope effect is obtained by comparing the isotopic composition of carbon 1 of the 3-phosphoglyceric acid formed in the reaction with that of the carbon dioxide source. a correction is made for carbon 1 of 3-phosphoglyceric acid which arises from carbon 3 of the starting ribulose bisphosphate. the isotope effect is k12/k13 = ...19853924094
influence of ph, o2, and temperature on the absorption properties of the secondary light-harvesting antenna in members of the family some rhodospirillaceae, the primary light-harvesting (lh i) antenna absorbs near-infrared light around 870 nm, whereas lh ii (holochrome b800-860) has a major absorption band between 850 and 860 nm (b860) and a minor absorbancy around 800 nm (b800). results show that, unlike lh i, holochrome b800-860 (lh ii) exhibits unstable light absorption properties in whole cells. this was observed in rhodopseudomonas capsulata grown anaerobically in light in weakly buffered carbohydrate medium; cultures ...19853928601
polyamines in photosynthetic eubacteria and extreme-halophilic archaebacteria.qualitative and quantitative determinations of polyamines have been done in 4 photosynthetic eubacteria and 6 extreme-halophilic archaebacteria. for comparison, 5 moderate-halophilic eubacteria were also analyzed to determine their polyamine contents. not only putrescine and spermidine but also homospermidine were found in the photosynthetic eubacteria, especially in the n2-fixing species, rhodospirillum and chromatium. norspermidine, norspermine, and spermine were not detected in the phototroph ...19853928615
distribution of multicopy single-stranded dna among myxobacteria and related species.multicopy single-stranded dna (msdna) is a short single-stranded linear dna originally discovered in myxococcus xanthus and subsequently found in stigmatella aurantiaca. it exists at an estimated 500 to 700 copies per chromosome (t. yee, t. furuichi, s. inouye, and m. inouye, cell 38:203-209, 1984). we found msdna in other myxobacteria, including myxococcus coralloides, cystobacter violaceus, cystobacter ferrugineus (cbfe17), nannocystis exedens, and nine independently isolated strains of m. xan ...19853932332
ionization constants of two active-site lysyl epsilon-amino groups of ribulosebisphosphate carboxylase/oxygenase.trinitrobenzene sulfonate rapidly inactivates ribulosebisphosphate carboxylase/oxygenase from both spinach and rhodospirillum rubrum. with large molar excesses of the reagent, the reactions obey pseudo-first order kinetics and the rates of inactivations are directly proportional to the concentrations of trinitrobenzene sulfonate; thus, there is no indication of reversible complexation of reagent with enzyme. saturating levels of the competitive inhibitor 2-carboxyribitol 1,5-bisphosphate reduce ...19853932347
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
membrane topology of light-harvesting protein b870-alpha of rhodospirillum rubrum g-9+. amino acid residues in contact with the lipid bilayer as inferred from labeling with photogenerated carbenes.the amino acid residues of the light-harvesting protein b870-alpha of rhodospirillum rubrum g-9+ that in the chromatophore membranes are in contact with the lipid phase were identified by hydrophobic photolabeling. three reagents have been used which all contained the trifluoromethyldiazirinylphenyl group as a photo-sensitive precursor of a carbene but which otherwise differed in shape, molecular structure, and in the way they interact with membranes. 3-trifluoromethyl-3-(m-[125i]iodophenyl)diaz ...19853934175
isolation, characterization, and comparison of a ubiquitous pigment-protein complex consisting of a reaction center and light-harvesting bacteriochlorophyll proteins present in purple photosynthetic bacteria.protein complexes (photochemical reaction complex; pr complex) bound to both light-harvesting bacteriochlorophyll-1 (lh-bchl-1) and reaction center bchl (rc-bchl) were purified from rhodospirillum rubrum (wild and carotenoid-less), rhodopseudomonas sphaeroides (wild), and chromatium vinosum (wild). another protein complex (lh-2 complex) bound to lh-bchl-2 was also purified from rps. sphaeroides. the bacteria were grown in the presence of a [14c]amino acid mixture. the purification procedure incl ...19853937841
comparative efficiency of primary light conversion in photosynthetic bacteria rhodospirillum rubrum and rhodopseudomonas viridis. 19853939722
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
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
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
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 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
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
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
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
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
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
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
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
purple-bacterial light-harvesting complexes. 19863082693
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 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
a novel fad-protein that allows effective reduction of methyl viologen by nadh (nadh-methyl viologen reductase) from photosynthetic bacterium, rhodospirillum rubrum: purification and 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 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
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
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