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truncation of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from rhodospirillum rubrum affects the holoenzyme assembly and activity.truncations of the subunit of ribulose bisphosphate carboxylase/oxygenase (rubisco) from rhodospirillum rubrum were generated by site-directed mutagenesis to examine the role of the c-terminal tail section. removal of the last and the penultimate alpha-helices in the tail section changes the quaternary structure of the protein. electrophoretic and electron microscope analysis revealed that the truncated subunits assemble into an octamer, whereas the wild-type enzyme has a dimeric structure. the ...19902109693
probing the bacteriochlorophyll binding site by reconstitution of the light-harvesting complex of rhodospirillum rubrum with bacteriochlorophyll a analogues.structural features of bacteriochlorophyll (bchl) a that are required for binding to the light-harvesting proteins of rhodospirillum rubrum were determined by testing for reconstitution of the b873 or b820 (structural subunit of b873) light-harvesting complexes with bchl a analogues. the results indicate that the binding site is very specific; of the analogues tested, only derivatives of bchl a with ethyl, phytyl, and geranylgeranyl esterifying alcohols and bchl b (phytyl) successfully reconstit ...19902110819
electron transfer between primary and secondary donors in rhodospirillum rubrum: evidence for a dimeric association of reaction centers.light-induced oxidation of the primary electron donor p and of the secondary donor cytochrome c2 was studied in whole cells of rhodospirillum rubrum in the presence of myxothiazole to slow down their reduction. 1. the primary and secondary electron donors are close to thermodynamic equilibrium during continuous illumination when the rate of the electron transfer is light-limited. this implies a long-range thermodynamic equilibration involving the diffusible cytochrome c2. a different behavior is ...19902112407
[the surface membrane charge of bacteria and its role in serine proteinase secretion by bacillus subtilis cells].univalent, bivalent and trivalent metal cations increase the fluorescence yield of 9-aminoacridine in the suspensions of chromatophores of the purple nonsulfur bacterium rhodospirillum rubrum isolated thylakoid membranes and cells of cyanobacterium anabaena variabilis, cells bacillus subtilis. the active cation concentrations increase about in 10 times with the decrease of their valency by one. it points to the fact that the changes in 9-aminoacridine fluorescence serve for the monitoring of the ...19902112959
comparison of the crystal structures of l2 and l8s8 rubisco suggests a functional role for the small subunit.comparison of the crystal structures of the l2 and l8s8 forms of ribulose-1,5-bisphosphate carboxylase from rhodospirillum rubrum and spinach respectively, reveals a remarkable similarity in the overall architecture of the l2 building blocks in the two enzymes. within the l subunits, no large conformational differences such as domain-domain rotations were found. in spite of a somewhat different packing of the l subunits in the l2 dimer, the active sites of the two enzymes are highly conserved. s ...19902113466
carboxylterminal deletion mutants of ribulosebisphosphate carboxylase from rhodospirillum rubrum.the carboxylterminal octapeptide of ribulosebisphosphate carboxylase from rhodospirillum rubrum, which lacks small subunits, shows homology to a highly conserved region near the amino terminus of the small subunits of hexadecameric ribulosebisphosphate carboxylases, which are composed of large and small subunits. truncations of the r. rubrum enzyme, which partially or completely deleted the region of homology, demonstrated that the region is not an important determinant of the catalytic efficien ...19902114311
the contribution of the carotenoid to the visible circular dichroism of the light-harvesting antenna of rhodospirillum rubrum.the visible c.d. spectrum of wild-type rhodospirillum rubrum shows positive bands [dratz, schultz & sauer (1966) brookhaven symp. biol. 19, 303-318] that are largely due to the b880 antenna pigments, bacteriochlorophyll a and carotenoids. the bacteriochlorophyll c.d. band was absent from the spectrum of r. rubrum g9, a mutant unable to synthesize coloured carotenoids, and could be partly restored by adding extracted carotenoids to freeze-dried membrane vesicles isolated from that mutant. therefo ...19902119174
chromatographic and protein chemical analysis of the ubiquinol-cytochrome c2 oxidoreductase isolated from rhodobacter sphaeroides.the ubiquinol-cytochrome c2 oxidoreductase (cytochrome bc1 complex) purified from chromatophores of rhodobacter sphaeroides consists of four polypeptide subunits corresponding to cytochrome b, c1, and the rieske iron-sulfur protein, as well as a 14-kda polypeptide of unknown function, respectively. in contrast, the complex isolated from rhodospirillum rubrum by the same procedure lacked a polypeptide corresponding to the 14-kda subunit. gel-permeation chromatography of the r. sphaeroides cytochr ...19902153104
molecular cloning, sequencing and expression of cytochrome c2 from rhodospirillum rubrum.cytochrome c2 (mr 12,840) of the purple photosynthetic bacterium rhodospirillum rubrum functions as a mobile electron carrier in the cyclic photosynthetic electron-transport system of this organism. it acts as the electron donor to photochemically oxidized reaction centres and is reduced in turn by electrons from the cytochrome bc1 complex. by using synthetic oligonucleotides based on the known amino acid sequence of the protein, the structural gene (cyca) has been identified and isolated. dna s ...19902154194
versatile protein engineering vectors for mutagenesis, expression and hybrid enzyme formation. 19902158660
soluble cytochromes and a photoactive yellow protein isolated from the moderately halophilic purple phototrophic bacterium, rhodospirillum salexigens.three soluble cytochromes were found in two strains of the halophilic non-sulfur purple bacterium rhodospirillum salexigens. these are cytochromes c2, c and c-551. cytochrome c2 was recognized by the presence of positive charge at the site of electron transfer (measured by laser flash photolysis), although the protein has an overall negative charge (pi = 4.7). cytochrome c2 has a high redox potential (300 mv) and is monomeric (13 kda). cytochrome c was recognized from its characteristic absorpti ...19902158819
assignments of 15n and 1h nmr resonances and a neutral ph ionization in rhodospirillum rubrum cytochrome c2.the phi nh proton and 15n resonances of the ligand histidine of rhodospirillum rubrum fericytochrome c2 are found at 14.7 and 184 ppm, respectively, contradicting the proposal that this proton is absent in the r. rubrum ferricytochrome. substitution of the deuterium atom for this proton causes small upfield shifts of the phi nitrogen in both oxidation states, indicating that the phi nh-peptide carboxyl hydrogen bond is not substantially weakened by the substitution. the proton and 15n resonances ...19902159778
characterization of ph-dependent conformational heterogeneity in rhodospirillum rubrum cytochrome c2 using 15n and 1h nmr.the 15n-enriched ferricytochrome c2 from rhodospirillum rubrum has been studied by 15n and 1h nmr spectroscopy as a function of ph. the 15n resonances of the heme and ligand tau nitrogen are broadened beyond detection because of paramagnetic relaxation. the 15n resonance of the ligand histidine phi nitrogen was unambiguously identified at 184 ppm (ph 5.6). the 15n resonances of the single nonligand histidine are observed only at low ph, as in the ferrocytochrome because of the severe broadening ...19902159779
resonance raman spectroscopy of cytochrome bc1 complexes from rhodospirillum rubrum: initial characterization and reductive titrations.resonance raman spectra of bc1 complexes from rhodospirillum rubrum have been obtained. various resonance conditions and the stoichiometric redox titration of the complex were used to isolate and identify the contributions of the heme c1 and heme b active sites to the observed spectra. the complex was found to partially photoreduce when exposed to laser excitation.19902165419
proton nmr study of the comparative electronic/magnetic properties and dynamics of the acid in equilibrium with alkaline transition in a series of ferricytochromes c'.the proton nmr spectra of ferricytochrome c' from rhodopseudomonas palustris, rhodospirillum molischianum, rhodospirillum rubrum, and chromatium vinosum have been investigated for the purpose of further elucidating the common spectral and/or structural properties for this subclass of cytochromes in the acidic and alkaline forms, and to characterize in detail the dynamics and structural basis for this acid in equilibrium with alkaline transition. the identification of strongly upfield-shifted mes ...19902168882
the pet genes of rhodospirillum rubrum: cloning and sequencing of the genes for the cytochrome bc1-complex.a cytochrome bc1-complex of rs. rubrum was isolated and the three subunits were purified to homogeneity. the n-terminal amino acid sequence of the purified subunits was determined by automatic edman degradation. the pet genes of rhodospirillum rubrum coding for the three subunits of the cytochrome bc1-complex were isolated from a genomic library of rs. rubrum using oligonucleotides specific for conserved regions of the subunits from other organisms and a heterologous probe derived from the genes ...19902176269
nitrogenase in the archaebacterium methanosarcina barkeri 227.the discovery of nitrogen fixation in the archaebacterium methanosarcina barkeri 227 raises questions concerning the similarity of archaebacterial nitrogenases to mo and alternative nitrogenases in eubacteria. a scheme for achieving a 20- to 40-fold partial purification of nitrogenase components from strain 227 was developed by using protamine sulfate precipitation, followed by using a fast protein liquid chromatography apparatus operated inside an anaerobic glove box. as in eubacteria, the nitr ...19902254255
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
purification of a light-harvesting b880 complex from wild-type rhodospirillum rubrum.the light-harvesting b880 complex of rhodospirillum rubrum was purified by a new method which allowed recovery of 66% of the amount present in the crude solubilized extract. electrophoretic analysis of the isolated complex, followed by either coomassie brilliant blue or silver staining, revealed only two low-molecular-weight polypeptides. when compared to a previously described preparation, the stability of the complex was considerably increased. in addition, the new procedure yielded b880 of hi ...19862420229
reconstitution of the h+-atpase complex of rhodospirillum rubrum by the beta subunit of the chloroplast coupling factor 1.a method is described for isolating the beta subunit from spinach chloroplast f1 (cf1). the isolated beta subunit reconstituted an active f1 hybrid with the f1 of rhodospirillum rubrum chromatophores from which the beta subunit had been removed. the cf1 beta subunit was similar to the isolated beta subunit of escherichia coli f1 (gromet-elhanan, z., khananshivili, d., weiss, s., kanazawa, h., and futai, m. (1985) j. biol. chem. 260, 12635-12640) in that it restored a substantial rate of atp hydr ...19862427516
role of water in processes of energy transduction: ca2+-transport atpase and inorganic pyrophosphatase.after the proposal of the chemiosmotic theory by mitchell (1966, 1979) it has been recognized that different membrane-bound enzymes are able to use the energy derived from ionic gradients for the synthesis of atp. these include the f1-atpases of mitochondria and chloroplasts, the ca2+-dependent atpase of sarcoplasmic reticulum and the (na+,k+)-atpase of plasma membrane. in these systems the process of energy transduction is fully reversible. the enzyme can use the energy derived from the hydroly ...19852428374
determination of the functional homology of beta subunits isolated from various f1-atpase complexes: their role in catalysis and coupled proton-translocation. 19882458598
division of divalent cations into two groups in relation to their effect on the coupling of the f0f1-atpase of rhodospirillum rubrum to the protonmotive force.divalent cations are divided into two groups in relation to their ability to promote atp synthase catalyzed reactions. in the presence of mg2+, the following pattern rules: (i) uncoupler-stimulated atp hydrolysis of rhodospirillum rubrum chromatophores which shows an optimum concentration of the divalent cation; (ii) atp-induced proton pumping in chromatophores; (iii) light-induced atp synthesis in chromatophores; (iv) no or very low atpase activity of purified f1-atpase unmasked by diethylstilb ...19892482079
carbonyl sulfide: an alternate substrate for but not an activator of ribulose-1,5-bisphosphate carboxylase.carbonyl sulfide, a competitive inhibitor of ribulose-bisphosphate carboxylase with respect to co2 (laing, w. a., and christeller, j. t. (1980) arch. biochem. biophys. 202, 592-600), is an alternate substrate. thiocarboxylation was monitored by mass spectrometry as the stoichiometric consumption of carbonyl sulfide. the product, 1-thio-3-phosphoglycerate, was identified by 13c nmr and uv absorption spectroscopy and measured by enzymic conversion to thiolactate, coupled to the oxidation of nadh. ...19892492523
crystal structure of the binary complex of ribulose-1,5-bisphosphate carboxylase and its product, 3-phospho-d-glycerate.the crystal structure of the binary complex of non-activated ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum and its product 3-phospho-d-glycerate has been determined to 2.9-a resolution. this structure determination confirms the proposed location of the active site (schneider, g., lindqvist, y., brändén, c.-i., and lorimer, g. (1986) embo j. 5, 3409-3415) at the carboxyl end of the beta-strands of the alpha/beta-barrel in the carboxyl-terminal domain. one molecule of ...19892492987
regulation of carbon monoxide dehydrogenase and hydrogenase in rhodospirillum rubrum: effects of co and oxygen on synthesis and activity.exposure of the photosynthetic bacterium rhodospirillum rubrum to carbon monoxide led to increased carbon monoxide dehydrogenase and hydrogenase activities due to de novo protein synthesis of both enzymes. two-dimensional gels of [35s]methionine-pulse-labeled cells showed that induction of co dehydrogenase synthesis was rapidly initiated (less than 5 min upon exposure to co) and was inhibited by oxygen. both co dehydrogenase and the co-induced hydrogenase were inactivated by oxygen in vivo and i ...19892498285
ammonium inhibition of nitrogenase activity in herbaspirillum seropedicae.the effect of oxygen, ammonium ion, and amino acids on nitrogenase activity in the root-associated n2-fixing bacterium herbaspirillum seropedicae was investigated in comparison with azospirillum spp. and rhodospirillum rubrum. h. seropedicae is microaerophilic, and its optimal dissolved oxygen level is from 0.04 to 0.2 kpa for dinitrogen fixation but higher when it is supplied with fixed nitrogen. no nitrogenase activity was detected when the dissolved o2 level corresponded to 4.0 kpa. ammonium, ...19892498287
the orientation of substrate and reaction intermediates in the active site of ribulose-1,5-bisphosphate carboxylase.there are four possible orientations of the substrate ribulose 1,5-bisphosphate in the active site of ribulose-1,5-bisphosphate carboxylase. distinction between these four possible orientations has been made on the basis of 31p nmr and borohydride-trapping experiments. the orientation of the reaction-intermediate analog, 2'-carboxy-d-arabinitol 1,5-bisphosphate with respect to the divalent metal ion was determined by 31p nmr studies of the quaternary complex, enzyme.co2.ni2+.2'-carboxyarabinitol ...19892498340
mapping of the puh messenger rnas from rhodospirillum rubrum. evidence for tandem promoters.the mrna transcripts of rhodospirillum rubrum gene puh, coding for the h subunit of the photoreaction center, and of genes flanking puh were analyzed by blot hybridization. open reading frame g115, upstream of structural gene puh, is transcribed as a 2.25-kilobase mrna. gene puh itself is transcribed as two mrnas of 1118 and 1032 nucleotides. mung bean nuclease protection analysis shows that the puh transcripts have different 5' termini within open reading frame g115 and a unique rho-independent ...19892499583
examination of subunit interactions at the active site of ribulose 1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum by hybridization of site-directed mutants.the two active sites of homodimeric ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum are constituted by interacting domains of adjacent subunits, in which residues from each are required for catalytic activity. active-site residues include lys-166 of one domain and glu-48 of the interacting domain from the adjacent subunit. whereas all substitutions for lys-166, introduced by site-directed mutagenesis, abolished catalytic activity, only a negatively charged residue (e.g., a ...19892500136
a cyanobacterial mutant requiring the expression of ribulose bisphosphate carboxylase from a photosynthetic anaerobe.ribulose bisphosphate carboxylase is essential for both photoautotrophic and photoheterotrophic growth of the cyanobacterium synechocystis 6803. however, a mutant lacking cyanobacterial carboxylase could be obtained by replacing the natural carboxylase gene with the corresponding gene from rhodospirillum rubrum, a photosynthetic anaerobe. this treatment produced an organism whose growth depended on the activity of the structurally and functionally dissimilar foreign carboxylase. as a further con ...19892503824
effect of nucleotides on the activity of dinitrogenase reductase adp-ribosyltransferase from rhodospirillum rubrum.the mechanism by which mgadp stimulates the activity of dinitrogenase reductase adp-ribosyltransferase (drat) has been examined by using dinitrogenase reductases from rhodospirillum rubrum, klebsiella pneumoniae, and azotobacter vinelandii as acceptor substrates. in the presence of 0.2 mm nad, maximal rates of adp-ribosylation of all three acceptors were observed at an adp concentration of 150 microm; in the absence of added adp, drat activity with the dinitrogenase reductases from r. rubrum and ...19892504283
nickel is required for the transfer of electrons from carbon monoxide to the iron-sulfur center(s) of carbon monoxide dehydrogenase from rhodospirillum rubrum.the role of nickel in co oxidation and electron flow was investigated in carbon monoxide dehydrogenase from rhodospirillum rubrum. the fe-s centers of oxidized, nickel-containing (holo) co dehydrogenase were completely reduced within 1 min of exposure to co. the fe-s centers of oxidized, nickel-deficient (apo) co dehydrogenase were not reduced during a 35-min incubation in the presence of co. apo-co dehydrogenase fe-s centers were reduced by dithionite. the fe-s centers of cyanide-inhibited, hol ...19892504284
nickel-specific, slow-binding inhibition of carbon monoxide dehydrogenase from rhodospirillum rubrum by cyanide.the inhibition of purified carbon monoxide dehydrogenase from rhodospirillum rubrum by cyanide was investigated in both the presence and absence of co and electron acceptor. the inhibition was a time-dependent process exhibiting pseudo-first-order kinetics under both sets of conditions. the true second-order rate constants for inhibition were 72.2 m-1 s-1 with both substrates present and 48.9 and 79.5 m-1 s-1, respectively, for the reduced and oxidized enzymes incubated with cyanide. co partiall ...19892504285
posttranslational regulatory system for nitrogenase activity in azospirillum spp.the mechanism for "nh4+ switch-off/on" of nitrogenase activity in azospirillum brasilense and a. lipoferum was investigated. a correlation was established between the in vivo regulation of nitrogenase activity by nh4cl or glutamine and the reversible covalent modification of dinitrogenase reductase. dinitrogenase reductase adp-ribosyltransferase (drat) activity was detected in extracts of a. brasilense with nad as the donor molecule. dinitrogenase reductase-activating glycohydrolase (drag) activ ...19892504694
reversible adp-ribosylation of dinitrogenase reductase in a nifd- mutant of rhodospirillum rubrum.dinitrogenase reductase from a rhodospirillum rubrum strain lacking dinitrogenase was reversibly adp-ribosylated in vivo in response to dark-light transitions. addition of ammonia also led to adp-ribosylation in this strain. these results demonstrate that reduced dinitrogenase is a satisfactory substrate for the reversible adp-ribosylation system of r. rubrum in vivo.19892504701
delta ph driven energy-linked nad+ reduction in rhodospirillum rubrum chromatophores.an artificial proton gradient provided sufficient energy to drive reverse electron transport from succinate to nadh:ubiquinone oxidoreductase in chromatophores isolated from rhodospirillum rubrum. the ph gradient created was able to reduce nad+. in chromatophores, the optimal rate of nad+ reduction was about 0.4-0.45 mumol nadh formed/min.mumol bacteriochlorophyll at delta ph 3. the presence of oligomycin was an obligate factor in the assay in order to observe the maximal rate of nad+ reduction. ...19892505679
demonstration and partial characterization of adp-ribosylation in pseudomonas maltophilia.adp-ribosylation of proteins occurs in many eukaryotes, and it is also the mechanism of action of a growing number of important bacterial toxins. to date, however, there is only one well-characterized adp-ribosylation system where the adp-ribosyltransferase and the substrate protein are both bacterial in origin, namely within the nitrogen-fixing bacterium rhodospirillum rubrum. the present paper demonstrates the endogenous adp-ribosylation of two proteins of mr 32,000 and 20,000 within pseudomon ...19892505752
genes coding for the reversible adp-ribosylation system of dinitrogenase reductase from rhodospirillum rubrum.nitrogen fixation activity in the photosynthetic bacterium rhodospirillum rubrum is controlled by the reversible adp-ribosylation of the dinitrogenase reductase component of the nitrogenase enzyme complex. this report describes the cloning and characterization of the genes encoding the adp-ribosyltransferase (drat) and the adp-ribosylglycohydrolase (drag) involved in this regulation. these genes are shown to be contiguous on the r. rubrum chromosome and highly linked to the nifhdk genes. sequenc ...19892506427
carbonyl sulfide inhibition of co dehydrogenase from rhodospirillum rubrum.carbonyl sulfide (cos) has been investigated as a rapid-equilibrium inhibitor of co oxidation by the co dehydrogenase purified from rhodospirillum rubrum. the kinetic evidence suggests that the inhibition by cos is largely competitive versus co (ki = 2.3 microm) and uncompetitive versus methylviologen as electron acceptor (ki = 15.8 microm). the data are compatible with a ping-pong mechanism for co oxidation and cos inhibition. unlike the substrate co, cos does not reduce the iron-sulfur centers ...19892510818
coupling of atp hydrolysis to phosphate uptake in rhodospirillum rubrum chromatophores under the influence of ca2+ and mg2+.the pi-atp exchange and atp hydrolytic reactions, by the f0f1 complex, were studied in rhodospirillum rubrum chromatophores in the dark. an optimal ph between 7.0 and 8.5 was determined for the hydrolytic and exchange reactions. under these conditions, the hydrolysis/exchange ratio was approximately 2. the kinetic analysis of the hydrolytic and exchange reactions using mg-atp as substrate showed a change in the hydrolysis/exchange ratio that varied between 2.0 and 2.8 as the substrate concentrat ...19892512287
protein phosphorylation and control of excitation energy transfer in photosynthetic purple bacteria and cyanobacteria.the function of phosphorylation of light-harvesting polypeptides is well characterised in chloroplasts of green plants, but the prokaryotic cyanobacteria and purple photosynthetic bacteria have quite different light-harvesting polypeptides whose structure and function cannot be controlled in precisely the same way. nevertheless, cyanobacteria show light-dependent phosphorylation of membrane polypeptides associated with photosystem ii and with the light-harvesting phycobilisome, and purple bacter ...19892512993
protein phosphorylation in purple photosynthetic bacteria.endogenous protein phosphorylation was shown in both in vitro and in vivo experiments in r. rubrum and in other purple photosynthetic bacteria. among the substrates of this protein kinase activity the apoproteins of the light harvesting complex were tentatively identified. phosphoamino acid analysis revealed the presence of phosphoserine, phosphothreonine and phosphotyrosine in r. rubrum. a tyrosine kinase was partially purified in the same bacteria.19892512995
evolution of antioxidant mechanisms: thiol-dependent peroxidases and thioltransferase among procaryotes.glutathione peroxidase and glutathione s-transferase both utilize glutathione (gsh) to destroy organic hydroperoxides, and these enzymes are thought to serve an antioxidant function in mammalian cells by catalyzing the destruction of lipid hydroperoxides. only two groups of procaryotes, the purple bacteria and the cyanobacteria, produce gsh, and we show in the present work that representatives from these two groups (escherichia coli, beneckea alginolytica, rhodospirillum rubrum, chromatium vinos ...19892515292
functional expression of a rhodospirillum rubrum gene encoding dinitrogenase reductase adp-ribosyltransferase in enteric bacteria.the function of the cloned drat gene of rhodospirillum rubrum was studied by placing it under the control of the tac promoter in the vector, pkk223-3. after induction with isopropyl-beta-d-thiogalactopyranoside, dinitrogenase reductase adp-ribosyltransferase (drat) activity was detected in crude extracts of the heterologous hosts escherichia coli and klebsiella pneumoniae. in addition, the expression of drat produced a nif- phenotype in the otherwise wild-type k. pneumoniae strains, the result o ...19892515993
ability of the phototrophic bacterium rhodospirillum rubrum to produce various poly (beta-hydroxyalkanoates): potential sources for biodegradable polyesters.studies have been carried out in order to optimize growth and culture conditions for the intracellular formation of poly(beta-hydroxyalkanoates) (pha) in the phototrophic, purple, non-sulphur bacterium rhodospirilum rubrum. its potential to produce novel copolymers was investigated. recently, it has become of industrial interest to evaluate these polyesters as potentially biodegradable plastics for a wide range of possible applications. on an industrial scale, the use of photosynthetic bacteria ...19892518731
atp-synthesis by proteoliposomes incorporating rhodospirillum rubrum f0f1 as measured with firefly luciferase: dependence on delta psi and delta ph.atp-synthesis catalyzed by proteoliposomes incorporating rhodospirillum rubrum f0f1 was driven by artificially applied electrochemical proton gradients. the time-course of atp-synthesis was followed continuously by means of firefly luciferase. correction methods were developed which allow one to calculate the initial rate of atp-synthesis from the observed luminescence kinetics. the following results were obtained: (1) atp-synthesis occurred above a threshold delta mu h+ of 90 mv; this threshold ...19892528991
amount and turnover rate of the f0f1-atpase and the stoichiometry of its inhibition by oligomycin in rhodospirillum rubrum chromatophores.the amount of f1-atpase in chromatophores from rhodospirillum rubrum was determined by western blotting using anti-rrf1 rabbit antibodies. 9.1 mmol f1 (mol bacteriochlorophyll)-1 was obtained or 14% of the total protein content of the chromatophores. the turnover rate of the f0f1-atpase was 17 molecules atp s-1 during synthesis, 2 molecules atp s-1 during hydrolysis under coupled conditions with mg2+ as the divalent cation, and 7 molecules atp s-1 during hydrolysis in the presence of carbonyl cy ...19892532130
f1-atpase from rhodopseudomonas blastica. 19892535110
the effect of equisetin on energy-linked reactions in rhodospirillum rubrum chromatophores.light-induced proton uptake, light-induced carotenoid absorbance shift, photophosphorylation, and hydrolysis of mg-atp, ca-atp, and ppi in rhodospirillum rubrum chromatophores are shown to be inhibited by the antibiotic equisetin. the mg- and ca-atpase activities of purified f0f1-atpase are inhibited by equisetin. in contrast, only the ca-atpase activity of purified f1-atpase is decreased by equisetin, whereas the mg-atpase is stimulated. both equisetin and n,n'-dicyclohexylcarbodiimide (dccd) i ...19892536535
extended x-ray absorption fine structure study of rhodospirillum rubrum and rhodospirillum molischianum cytochromes c': relationship between heme stereochemistry and spin state.an exafs study on the oxidized and reduced forms of cytochromes c' from rhodospirillum rubrum and rhodospirillum molischianum was performed at ph 7. the cytochromes c' have an apparent coordination number of 5 in both oxidation states. average fe-ligand bond lengths of 2.02 +/- 0.025 and 2.06 +/- 0.025 a are obtained in their oxidized and reduced forms, respectively. by use of suitable values for the fe-nhis bond length and fe out-of-plane displacement, as determined by small molecule crystallog ...19892541757
steric and hydrophobic effects in alkyl isocyanide binding to rhodospirillum molischianum cytochrome c'.equilibrium constants for the binding of a series of alkyl isocyanides to ferrous cytochrome c' from rhodospirillum molischianum have been measured spectrophotometrically. the equilibrium constants range from 3.3 m-1 to 2.6 x 10(2) m-1 and follow the order methyl greater than ethyl less than n-propyl less than tert-butyl less than n-butyl less than amyl less than cyclohexyl less than n-hexyl. the decrease in equilibrium constant from methyl to ethyl isocyanide provides evidence for a steric inte ...19892541775
examination of the function of active site lysine 329 of ribulose-bisphosphate carboxylase/oxygenase as revealed by the proton exchange reaction.diverse approaches that include site-directed mutagenesis have indicated a catalytic role of lys-329 of ribulosebisphosphate carboxylase/oxygenase from rhodospirillum rubrum. to determine whether lys-329 is required for the initial enolization of ribulose bisphosphate or for some subsequent step in the overall reaction pathway, the competence of position 329 mutant proteins (devoid of carboxylase activity) in catalyzing exchange of solvent protons with the c-3 proton of substrate has now been ex ...19892545684
the rhodospirillum rubrum cytochrome bc1 complex: peptide composition, prosthetic group content and quinone binding.a cytochrome bc1 complex, essentially free of bacteriochlorophyll, has been purified from the photosynthetic purple non-sulfur bacterium rhodospirillum rubrum. the complex catalyzes electron flow from quinol to cytochrome c (turnover number = 75 s-1) that is inhibited by low concentrations of antimycin a and myxothiazol. the complex contains only three peptide subunits: cytochrome b (mr = 35,000); cytochrome c1 (mr = 31,000) and the rieske iron-sulfur protein (mr = 22,400). em values (ph 7.4) we ...19892548618
characterization of four herbicide-resistant mutants of rhodopseudomonas viridis by genetic analysis, electron paramagnetic resonance, and optical spectroscopy.herbicides of the triazine class block electron transfer in the photosynthetic reaction centers of purple bacteria and psii of higher plants. they are thought to act by competing with one of the electron acceptors, the secondary quinone, qb, for its binding site. several mutants of the purple bacterium rhodopseudomonas viridis resistant to terbutryn [2-(methylthio)-4-(ethylamino)-6-(tert-butylamino)-s-triazine] have been isolated by their ability to grow photosynthetically in the presence of the ...19892550055
identification of a ni- and fe-containing cluster in rhodospirillum rubrum carbon monoxide dehydrogenase.methyl viologen-oxidized carbon monoxide dehydrogenase (codh) from rhodospirillum rubrum exhibits complex epr. comparison to epr of oxidized apo-codh (codh from which ni is lacking) leads to the identification of signals whose intensity is correlated with the presence of ni. 61ni labeling observably broadens the sharpest feature of these signals, as does 57fe. r. rubrum codh thus contains a cluster containing both ni and fe. the epr associated with this cluster is unlike any epr previously attri ...19892550436
purification and partial characterization of glutamine synthetase from the photosynthetic bacterium rhodospirillum rubrum.glutamine synthetase (l-glutamate: ammonia ligase (adp-forming), ec 6.3.1.2) from the photosynthetic bacterium rhodospirillum rubrum grown under nitrogen fixing conditions has been purified to homogeneity. the purification procedure involves affinity chromatography on adp-agarose type 2 as the major purification step. the recovery in the purification is 70%. the specific activity of the purified enzyme is about 10-times higher in the gamma-glutamyl transferase assay than in the coupled biosynthe ...19892562919
regulation of nitrogenase activity by reversible adp ribosylation. 19892575970
r-body-producing bacteria.until 10 years ago, r bodies were known only as diagnostic features by which endosymbionts of paramecia were identified as kappa particles. they were thought to be limited to the cytoplasm of two species in the paramecium aurelia species complex. now, r bodies have been found in free-living bacteria and other paramecium species. the organisms now known to form r bodies include the cytoplasmic kappa endosymbionts of p. biaurelia and p. tetraurelia, the macronuclear kappa endosymbionts of p. cauda ...19892651865
isolation and partial characterization of a cytochrome-o complex from chromatophores of the photosynthetic bacterium rhodospirillum rubrum fr1.a cytochrome-o complex was isolated from chromatophores of photoheterotrophically grown rhodospirillum rubrum fr1. the enzyme was extracted with the non-denaturating detergent taurodeoxycholate and subsequently purified by sucrose-density-gradient centrifugation and gel-permeation hplc. the complex contains two types of cytochromes, one of them cytochrome o, and two copper atoms. it catalyzes the reduction of molecular oxygen, when n,n,n',n'-tetramethyl-p-phenylenediamine or ubiquinol 10 are off ...19892659347
linear optimization of predictors for secondary structure. application to transbilayer segments of membrane proteins.sliding-window averaging of amino acid properties is a standard method for predicting protein secondary structure. for example, transmembrane segments are predicted to occur near the peaks in a hydropathy plot of a membrane protein. such a scheme (linear convolutional recognizer, lcr) assigns a number (weight) to each type of monomer, and then convolutes some window function with the sequence of weights. the window has commonly been rectangular, and the weights derived from singlet amino acid fr ...19892685329
crystal structure of the complex of ribulose-1,5-bisphosphate carboxylase and a transition state analogue, 2-carboxy-d-arabinitol 1,5-bisphosphate.the crystal structure of the binary complex of nonactivated ribulose-1,5-bisphosphate carboxylase/oxygenase from rhodospirillum rubrum and a transition state analogue, 2-carboxy-d-arabinitol 1,5-bisphosphate has been determined to 2.6 a resolution with x-ray crystallographic methods. the transition state analogue binds in a rather extended conformation at the active site. the orientation of the transition state analogue within the active site could be determined from the electron density maps. t ...19892708355
1h-nmr studies of high-potential iron-sulfur protein from the purple phototrophic bacterium, rhodospirillum tenue.the high-potential iron-sulfur protein (hipip) from rhodospirillum tenue (strain 3761) shows only a weak (20-25%) sequence similarity to hipips from chromatium vinosum, ectothiorhodospira halophila and ectothiorhodospira vacuolata, including the strict conservation of only two of the twelve residues assumed to be in the 4fe-4s cluster packing region [tedro, s. m., meyer, t. e. and kamen, m. d. (1979) j. biol. chem. 254, 1495-1500]. in spite of these differences, the general range and distributio ...19892714284
rhodospirillum centenum, sp. nov., a thermotolerant cyst-forming anoxygenic photosynthetic bacterium.a novel non-sulfur purple photosynthetic bacterium, designated rhodospirillum centenum, was isolated from an enrichment culture designed to favor growth of anoxygenic photosynthetic n2-fixing bacteria. r. centenum grows optimally at 40-42 degrees c and has the capacity to produce cytoplasmic 'r bodies', refractile structures not observed hitherto in photosynthetic prokaryotes. the bacterium is also unusual among photosynthetic bacteria in that it forms desiccation-resistant cysts when grown aero ...19892757370
isolation, characterization, and biological activity of ferredoxin-nad+ reductase from the methane oxidizer methylosinus trichosporium ob3b.a ferredoxin-nad+ oxidoreductase (ec 1.18.1.3) has been isolated from extracts of the obligate methanotroph methylosinus trichosporium ob3b. this enzyme was shown to couple electron flow from formate dehydrogenase (nad+ requiring) to ferredoxin. ferredoxin-nad+ reductase was purified to homogeneity by conventional chromatography techniques and was shown to be a flavoprotein with a molecular weight of 36,000 +/- 1,000. this ferredoxin reductase was specific for nadh (km, 125 microm) and coupled e ...19892768195
distribution of delta-aminolevulinic acid biosynthetic pathways among phototrophic bacterial groups.two biosynthetic pathways are known for the universal tetrapyrrole precursor, delta-aminolevulinic acid (ala). in the ala synthase pathway which was first described in animal and some bacterial cells, the pyridoxal phosphate-dependent enzyme ala synthase catalyzes condensation of glycine and succinyl-coa to form ala with the loss of c-1 of glycine as co2. in the five-carbon pathway which was first described in plant and algal cells, the carbon skeleton of glutamate is converted intact to ala in ...19892789025
oxidation of cytochrome c2 and of cytochrome c by reaction centers of rhodospirillum rubrum and rhodobacter sphaeroides. the effect of ionic strength and of lysine modification on oxidation rates.the oxidation of cytochrome c2 by the photooxidized reaction center bacteriochlorophyll, p+-870, in chromatophores of rhodospirillum rubrum can be described using second-order kinetics at all ionic strengths. in a system consisting of isolated r. rubrum reaction centers and purified r. rubrum cytochrome c2, the oxidation of cytochrome c2 also follows second-order kinetics. in both cases, the reaction rates at low ionic strength are weakly dependent on the ionic strength. the data suggest that th ...19872820485
sequence analysis of the alcaligenes eutrophus chromosomally encoded ribulose bisphosphate carboxylase large and small subunit genes and their gene products.the nucleotide sequence of the chromosomally encoded ribulose bisphosphate carboxylase/oxygenase (rubpcase) large (rbcl) and small (rbcs) subunit genes of the hydrogen bacterium alcaligenes eutrophus atcc 17707 was determined. we found that the two coding regions are separated by a 47-base-pair intergenic region, and both genes are preceded by plausible ribosome-binding sites. cotranscription of the rbcl and rbcs genes has been demonstrated previously. the rbcl and rbcs genes encode polypeptides ...19872820933
the reaction domain on rhodospirillum rubrum cytochrome c2 and horse cytochrome c for the rhodospirillum rubrum cytochrome bc1 complex.the interaction of the rhodospirillum rubrum cytochrome bc1 complex with r. rubrum cytochrome c2 and horse cytochrome c was studied using specific lysine modification and ionic strength dependence methods. in order to define the reaction domain on cytochrome c2, several fractions consisting of mixtures of singly labeled carboxydintrophenyl-cytochrome c2 derivatives were employed. fraction a consisted of a mixture of derivatives modified at lysines 58, 81, and 109 on the back of cytochrome c2, wh ...19872820990
incorporation of reaction centers into submitochondrial particles resulting in light induced electron transfer.conditions for the incorporation of reaction centers, isolated from rhodospirillum rubrum, into submitochondrial particles have been studied. incorporation of the reaction centers into the lipid bilayer occurs in both orientations. electron flow from the light activated reaction center to the b-c1 complex is demonstrated. preliminary data on the reaction kinetics of the b cytochromes are given.19872823802
nickel-deficient carbon monoxide dehydrogenase from rhodospirillum rubrum: in vivo and in vitro activation by exogenous nickel.an inactive, ni-deficient form of carbon monoxide (co) dehydrogenase [carbon-monoxide:(acceptor) oxidoreductase; ec 1.2.99.2], designated apo-co dehydrogenase, accumulated in rhodospirillum rubrum when cells were grown in the absence of ni and treated with co. in vivo, both co dehydrogenase activity and hydrogenase activity increased several hundred fold upon addition of 2 microm nicl2. apo-co dehydrogenase was purified to homogeneity and differed from holo-co dehydrogenase only in its activity ...19882829176
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 ...19882832374
ph-induced changes in rhodospirillum rubrum cytochrome c2 and subsequent renaturation: an 15n nmr study.the 15n-enriched ferrocytochrome c2 from rhodospirillum rubrum was studied by 15n nmr at different solvent ph values. the mobility and chemical shift of the n-terminal glutamic acid (335.4 ppm at ph 5.1) were found to depend on ph. it was least mobile between ph 8 and 9.0, which is explained in terms of ph-dependent conformational changes and formation of salt linkages and/or hydrogen bonds. the resonances of the lysine side chains are centered around 341.7 ppm at low ph and move upfield with ph ...19882834719
the structural genes coding for the l and m subunits of rhodospirillum rubrum photoreaction 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 ...19882836391
15n and 1h nmr studies of rhodospirillum rubrum cytochrome c2.15n-enriched cytochrome c2 was purified from rhodospirillum rubrum that had been grown on 15nh4cl, and the diamagnetic iron(ii) form of the cytochrome was studied by 15n and 1h nmr spectroscopy. 15n resonances of the four pyrrole nitrogens, the ligand histidine nitrogens, the highly conserved tryptophan indole nitrogen, and some proline nitrogens are assigned. the resonances of the single nonligand histidine are observed only at low ph because of severe broadening produced by proton tautomerizat ...19882837275
regulation of ribulose bisphosphate carboxylase expression in rhodospirillum rubrum: characteristics of mrna synthesized in vivo and in vitro.the synthesis of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubpcase) in rhodospirillum rubrum was regulated by the co2 concentration in the culture medium. the specific activity of rubpcase in cells grown photolithotrophically in low concentrations of co2 (1.5%) was five to ten times higher than that in cultures grown at high concentrations of co2 (10%). increased enzyme activity was reflected by an increase in both rubpcase mrna and rubpcase protein. rubpcase expression was also studied ...19882842301
properties and regulation of 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
structural studies of rubisco from tobacco.an electron density map of ribulose 1,5-bisphosphate carboxylase-oxygenase (rubisco) from tobacco (nicotiana tabacum) has been obtained by x-ray crystallography at a nominal resolution of 0.34 nm. phases were determined by multiple isomorphous replacement with three heavy atom derivatives and then refined by solvent flattening. rubisco is barrel-shaped, and has (422) symmetry. the fourfold axis runs down an open central channel, concentric with the barrel. the molecule measures 10.5 nm along the ...19862878449
changes in amino acid and nucleotide pools of rhodospirillum rubrum during switch-off of nitrogenase activity initiated by nh4+ or darkness.amino acid and nucleotide pools were measured in nitrogenase-containing rhodospirillum rubrum cultures during nh4+- or dark-induced inactivation (switch-off) of the fe protein. a big increase in the glutamine pool size preceded nh4+ switch-off of nitrogenase activity, but the glutamine pool remained unchanged during dark switch-off. furthermore, methionine sulfoximine had no effect on the rate of dark switch-off, suggesting that glutamine plays no role in this process. in the absence of nh4+ aza ...19872878918
coreconstitution of bacterial atp synthase with monomeric bacteriorhodopsin into liposomes. a comparison between the efficiency of monomeric bacteriorhodopsin and purple membrane patches in coreconstitution experiments.the conditions for coreconstitution of a bacterial atp synthase and bacteriorhodopsin into lecithin liposomes and for light driven atp synthesis have been optimized. a rate of maximally 280 nmol atp min-1 mg atp synthase-1 was achieved with monomerized bacteriorhodopsin compared with a rate of up to 45 nmol atp min-1 mg-1 found for proteoliposomes containing bacteriorhodopsin in the form of purple membrane patches. the different rates are explained by the finding that monomeric bacteriorhodopsin ...19872883008
amino acid concentrations in rhodospirillum rubrum during expression and switch-off of nitrogenase activity.the amino acid concentrations in the phototrophic bacterium rhodospirillum rubrum were measured during growth under nif-repressing and nif-derepressing conditions. the effects of ammonium, glutamine, darkness, phenazine methosulfate, and the inhibitors methionine sulfoximine and azaserine on amino acid levels of cells were tested. the changes were compared to changes in whole-cell nitrogenase activity and adp-ribosylation of dinitrogenase reductase. glutamate was the dominant amino acid under ev ...19872885306
essentiality of glu-48 of ribulose bisphosphate carboxylase/oxygenase as demonstrated by site-directed mutagenesis.previous reports provide indirect evidence for the presence of glu-48 at the active site of ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum. this possibility has been examined directly by replacement of glu-48 with glutamine via site-directed mutagenesis. this single amino acid substitution does not prevent subunit association or ligand binding. however, the glu-48 mutant is severely deficient in catalytic activity, exhibiting a kcat only 0.05% that of wild-type enzyme. th ...19872886121
activation of mg-atp hydrolysis in isolated rhodospirillum rubrum h+-atpase.the effects of lauryl dimethylamine oxide on the rhodospirillum rubrum h+-atpase have been studied. this detergent activates mg2+-dependent atp hydrolysis in the isolated r. rubrum f0-f1 34-fold, whereas the ca2+-atpase activity is only slightly modified. atpase activation by lauryl dimethylamine oxide enhances the effect on atp hydrolysis exerted by free mg2+ ions. concentrations of free mg2+ in the range of 0.025 mm favor activation while higher concentrations inhibit atpase activity by approx ...19872889424
properties and regulation of the h+-atp synthase of mitochondria.a brief survey is made of the function of the h+-atp synthase of mitochondria with emphasis on how it is regulated. a main regulatory factor is a low molecular weight protein whose binding to the enzyme appears to be essential for optimal accumulation of atp as driven by electron transport. the atp synthase is also controlled by adp that, by binding to a site in the enzyme, inhibits atp hydrolysis. data on the spontaneous synthesis of a tightly bound atp are discussed. apparently, this requires ...19882896020
subtle alteration of the active site of ribulose bisphosphate carboxylase/oxygenase by concerted site-directed mutagenesis and chemical modification.both activities of ribulose bisphosphate carboxylase/oxygenase are dependent on carbamylation by co2 of a specific lysyl epsilon-amino group (lys-191 of the enzyme from rhodospirillum rubrum). to examine the stringency of the requirement for this lysyl side chain, lys-191 was converted to an aminoethylcysteinyl residue (net replacement of a gamma-methylene group by a sulfur atom) by a combination of site-directed mutagenesis and subsequent chemical modification. the purified cys-191 mutant was t ...19882896501
some evolutionary relationships of the primary biological catalysts glutamine synthetase and rubisco. 19872900091
conversion of coupling factor 1 of rhodospirillum rubrum from a ca2+-atpase into a mg2+-atpase.isolation of f1-atpase from rhodospirillum rubrum by chloroform extraction of chromatophores, followed by purification on a glycerol gradient, results in a very pure enzyme preparation containing five subunits with high ca2+-atpase activity (15 mumol per min per mg protein). furthermore, conditions are reported under which the purified f1 exhibits mg2+-dependent atpase activity of about 35 mumol per min per mg protein. nahco3 stimulates the mg2+-activity from 1.5 mumol per min per mg protein to ...19882901272
diethylstilbestrol. interactions with membranes and proteins and the different effects upon ca2+- and mg2+-dependent activities of the f1-atpase from rhodospirillum rubrum.the hydrophobic compound diethylstilbestrol inhibits the generation of the proton gradient and the membrane potential in chromatophores from rhodospirillum rubum and dissipates proton gradients over asolectin vesicle membranes. the ca2+-atpase activity of chromatophores, of purified f0f1-atpase and of purified f1-atpase is also decreased in the presence of diethylstilbestrol. other repressed activities are the pyrophosphatase activity of soluble pyrophosphatase from yeast and the nadh oxidation ...19882901353
dna sequence of a gene cluster coding for subunits of the f0 membrane sector of atp synthase in rhodospirillum rubrum. support for modular evolution of the f1 and f0 sectors.a region was cloned from the genome of the purple non-sulphur photobacterium rhodospirillum rubrum that contains genes coding for the membrane protein subunits of the f0 sector of atp synthase. the clone was identified by hybridization with a synthetic oligonucleotide designed on the basis of the known protein sequence of the dicyclohexylcarbodi-imide-reactive proteolipid, or subunit c. the complete nucleotide sequence of 4240 bp of this region was determined. it is separate from an operon descr ...19882902844
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
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