Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| cyclic voltammetry and 1h-nmr of rhodopseudomonas palustris cytochrome c2. probing surface charges through anion-binding studies. | the effects of increasing concentrations of cl-, clo4-, and hco3- on the redox potential of rhodopseudomonas palustris cytochrome c2 indicate that the two polyatomic anions bind specifically to the protein at one site, while chloride simply exerts an ionic atmosphere effect. the change in e degree upon specific anion binding allows us to probe for the influence of surface charges on the redox potential of cytochromes c. the decrease in redox potential at null ionic strength (delta e degree i = 0 ... | 1995 | 7588763 |
| benzoate-coenzyme a ligase, encoded by bada, is one of three ligases able to catalyze benzoyl-coenzyme a formation during anaerobic growth of rhodopseudomonas palustris on benzoate. | the first step of anaerobic benzoate degradation is the formation of benzoyl-coenzyme a by benzoate-coenzyme a ligase. this enzyme, purified from rhodopseudomonas palustris, is maximally active with 5 microm benzoate. to study the molecular basis for this reaction, the benzoate-coenzyme a ligase gene (bada) was cloned and sequenced. the deduced amino acid sequence of bada showed substantial similarity to other coenzyme a ligases, with the highest degree of similarity being that to 4-hydroxybenzo ... | 1995 | 7592432 |
| electron paramagnetic resonance studies of ferric cytochrome c' from photosynthetic bacteria. | electronic ground nature of ferric cytochromes c' isolated from five photosynthetic bacteria. chromatium vinosum atcc 17899, rhodobacter capsulatus atcc 11166, rhodopseudomonas palustris atcc 17001, rhodospirillum molischianum atcc 14031, and rhodospirillum rubrum atcc 11170 has been investigated by electron paramagnetic resonance (epr) spectroscopy. epr spectra indicate that the electronic ground state of five ferric cytochromes c' is a quantum mechanical admixed-spin state of a high spin (s = ... | 1995 | 7669805 |
| refined crystal structure of ferrocytochrome c2 from rhodopseudomonas viridis at 1.6 a resolution. | the three-dimensional structure of ferrocytochrome c2 from the purple photosynthetic bacterium rhodopseudomonas viridis has been refined to a final r-factor of 18.2% for 15,014 unique reflections collected by synchrotron radiation between 6.0 and 1.6 a resolution. the refined model includes 107 amino acid residues, one heme prosthetic group and 125 water molecules. the root-mean-square deviations from the ideal bond lengths and angles were 0.014 a and 3.0 degrees, respectively. the atomic coordi ... | 1995 | 7674304 |
| crystallographic refinement at 2.3 a resolution and refined model of the photosynthetic reaction centre from rhodopseudomonas viridis. | the atomic model of the photosynthetic reaction centre from the purple bacterium rhodopseudomonas viridis has been refined to an r-value of 0.193 at 2.3 a resolution. the refined model contains 10,288 non-hydrogen atoms; 10,045 of these have well defined electron density. a luzzati-plot indicates an average co-ordinate error of 0.26 a. during refinement, the positions of a partially ordered carotenoid, a unibiquinone in the partially occupied qb site, a detergent molecule, seven putative sulphat ... | 1995 | 7877166 |
| picture story. the inverse light-bulb. | 1995 | 7773787 | |
| modeling the quinone-b binding site of the photosystem-ii reaction center using notions of complementarity and contact-surface between atoms. | functional identity and significant similarities in cofactors and sequence exist between the l and m reaction center proteins of the photosynthetic bacteria and the d1 and d2 photosystem-ii reaction center proteins of cyanobacteria, algae, and plants. a model of the quinone (qb) binding site of the d1 protein is presented based upon the resolved structure of the qb binding pocket of the l subunit, and introducing novel quantitative notions of complementarity and contact surface between atoms. th ... | 1995 | 7784425 |
| magnetic resonance of fe-s clusters: isolation and characterization of a 7fe ferredoxin from rhodopseudomonas palustris. | a novel iron-sulfur protein from the photosynthetic purple bacterium rhodopseudomonas palustris was purified to homogeneity and identified as a ferredoxin on the basis of its physicochemical properties. based on the uv/vis spectrum, iron quantitation, cyclic voltammetry, epr, and 1h nmr data, the ferredoxin is found to contain two iron-sulfur clusters, one [3fe-4s] and one [4fe-4s], which places this protein in the class of 7fe ferredoxins. the voltammetric peak potentials of the two clusters ar ... | 1995 | 7793975 |
| structure and properties of the bacteriochlorophyll binding site in peripheral light-harvesting complexes of purple bacteria. | in this paper, we have examined, using ft resonance raman spectroscopy, the bacteriochlorophyll (bchl) binding sites in the peripheral light-harvesting complexes extracted from a number of purple bacterial strains. a comparison of interactions of the bchl molecules with their binding sites in these lh2 complexes, together with the primary sequences of the alpha and beta polypeptides, allows three amino acids to be proposed to be involved in the hydrogen bonding of the 9-keto carbonyl of one of t ... | 1995 | 7819244 |
| molecular and crystal structure of an amphiphile: 4'-propoxybiphenyl-4-methyl-n,n-dimethylamineoxide dihydrate. | a novel amphiphile, 4'-propoxybiphenyl-4-methyl-n,n-dimethylamineoxide, has been synthesized, crystallized (p2(1)/a, a = 9.084 a, b = 8.911 a, c = 22.460 a, beta = 96.224 degrees) and its crystal structure was determined. the amphiphile forms a bilayer in which the amineoxide oxygen of each molecule binds two water molecules. in the hydrophobic part of the bilayer the biphenyls form edge-to-face contacts, in the polar layer there is a hydrogen bonding network. the potential use of the compound a ... | 1995 | 7696300 |
| energetics of the quinone electron acceptor complex in rubrivivax gelatinosus. | the ph and temperature dependences of the free energy stabilization of the q-a and q-b semiquinone anions (qa and qb are respectively the primary and secondary quinone electron acceptors) were studied in antenna-reaction centre complex from rubrivivax (r.) gelatinosus. this was achieved by measuring the rate constants of the p+q-a (kap) and p+q-b (kbp) (p is the primary electron donor) charge recombination processes by flash-induced absorption spectroscopy. despite the high primary sequence anal ... | 1995 | 8534672 |
| synthetic s-(2,3-dihydroxypropyl)-cysteinyl peptides derived from the n-terminus of the cytochrome subunit of the photoreaction centre of rhodopseudomonas viridis enhance murine splenocyte proliferation. | various lipopeptides representing the n-terminal part of the cytochrome subunit of the photosynthetic reaction centre from the purple bacterium rhodopseudomonas virdis were prepared by solid-phase peptide synthesis. these lipopeptides consisted of a s-[2,3-dihydroxypropyl]-cysteinyl (dhc) residue n-terminally coupled to the nonapeptide fepppattt. different numbers of palmitoyl (pam) chains were attached to dhc via ester and/or amide bonds. the lipopeptide dhc(pam)2-fepppattt containing two ester ... | 1995 | 9222995 |
| metabolism of cyclohexane carboxylic acid by the photosynthetic bacterium rhodopseudomonas palustris. | cyclohexane carboxylate supported relatively rapid growth (doubling times 7-8 h) of rhodopseudomonas palustris under oxic or photosynthetic conditions, but did not serve as a substrate for either of the known aromatic coa ligases. a coa ligase that thioesterifies cyclohexane carboxylate was partially purified and did not cross react immunologically with the two coa ligases purified previously from this bacterium. crude extracts of r. palustris cells grown with a range of aromatic or alicyclic ac ... | 1995 | 8572887 |
| energy transfer in spectrally inhomogeneous light-harvesting pigment-protein complexes of purple bacteria. | energy transfer within the peripheral light-harvesting antenna of the purple bacteria rhodobacter sphaeroides and rhodopseudomonas palustris was studied by one- and two-color pump-probe absorption spectroscopy with approximately 100-fs tunable pulses at room temperature and at 77 k. the energy transfer from b800 to b850 occurs with a time constant of 0.7 +/- 0.05 ps at room temperature and 1.8 +/- 0.2 ps at 77 k and is similar in both species. anisotropy measurements suggest a limited but fast b ... | 1995 | 8599629 |
| light-harvesting mechanisms in purple photosynthetic bacteria. | the processes by which photosynthetic bacteria capture light and transfer the energy to the reaction centre continue to be studied using an array of methodologies, both physical and biological. with the publication this year of the crystal structure of the lh2 complex from rhodopseudomonas acidophila and the projection structure of the lh1 complex from rhodospirillum rubrum, structural models now exist for all the components in the bacterial photosynthetic apparatus. | 1995 | 8749368 |
| structural model of the photosynthetic reaction center of rhodobacter capsulatus. | the reaction center (rc) from the photosynthetic bacterium rhodobacter (rb.) capsulatus has been the subject of a considerable amount of molecular biological and spectroscopic work aimed at improving our understanding of the primary steps of photosynthesis. however, no three-dimensional structure is available for this protein. we present here a model obtained by combining information from the structure of the highly homologous rc from rhodopseudomonas (rps.) viridis with molecular mechanics and ... | 1995 | 7479696 |
| [isolation and identification of rhodopseudomonas viridis and rhodopseudomonas sulfoviridis]. | under selective culture conditions, two pure cultures (strain g and strain sg) of the purple nonsulfur photosynthetic bacteria containing bacteriochlorophyll b were isolated from pulp effluent and sludge of sewage treatment plant by means of agar shake dilution. although the cells of strain g and strain sg contained bacteriochlorophyll b and carotenoids, intra-cytoplasmic membranes were of lamellar type parallel to cytoplasmic membrane, the two strains differ in using various organic carbon sour ... | 1995 | 7483578 |
| structure of the photochemical reaction centre of a spheroidene-containing purple-bacterium, rhodobacter sphaeroides y, at 3 a resolution. | the crystal structure of the photochemical reaction centre from rhodobacter sphaeroides y, a carotenoid-containing wild-type purple bacterium, has been determined at 3 a resolution. this membrane complex consists of three subunits (281, 307 and 260 residues, respectively) and ten cofactors. it was crystallized in presence of beta-d-octylglucoside. the crystals are orthorhombic with unit-cell dimensions, a = 143.7, b = 139.8, c = 78.7 a, space group p2(1)2(1)2(1) with four molecules in the unit c ... | 1995 | 15299304 |
| hydrogen-bond interactions of the primary donor of the photosynthetic purple sulfur bacterium chromatium tepidum. | we have used near-infrared fourier transform (pre)resonance raman spectroscopy to determine the protein interactions with the bacteriochlorophyll (bchl) dimer constituting the primary electron donor, p, in the reaction center (rc) from the thermophilic purple sulfur bacterium chromatium tepidum. in addition, we report the alignment of partial sequences of the l and m protein subunits of c. tepidum rcs in the vicinity of the primary donor with those of rhodobacter sphaeroides and rhodopseudomonas ... | 1996 | 8756709 |
| two-dimensional structure of light harvesting complex ii (lhii) from the purple bacterium rhodovulum sulfidophilum and comparison with lhii from rhodopseudomonas acidophila. | within the membranes of photosynthetic bacteria, up to three types of light harvesting complexes (lhi, lhii, lhiii) are found. these complexes absorb photons and transfer the excitation energy to the photosynthetic reaction centre. the lh complexes comprise units that contain alpha and beta polypeptides with associated pigment molecules. | 1996 | 8805531 |
| purification, molecular cloning and expression in escherichia coli of homospermidine synthase from rhodopseudomonas viridis. | homospermidine synthase (hss) catalyzes the synthesis of the polyamine homospermidine from 2 mol putrescine in an nad(+)-dependent reaction. in this study, the enzyme was purified from anaerobically grown cultures of the photosynthetic bacterium rhodopseudomonas viridis to electrophoretic homogeneity using a three-step procedure. the enzyme was shown to be a homodimer of 52-kda subunits. six endopeptidase lysc fragments were sequenced from the purified protein. with the aid of degenerate primers ... | 1996 | 8841401 |
| spectral broadening of interacting pigments: polarized absorption by photosynthetic proteins. | excitonic interaction between pigment molecules is largely responsible for the static and dynamic spectroscopic properties of photosynthetic pigment-proteins. this paper provides a new description of its effect on polarized absorption spectroscopy, in particular on circular dichroism (cd). we investigate excitonic spectra of finite width and use "spectral moments" to compare 1) inhomogeneously broadened excitonic spectra, 2) spectra that are (homogeneously broadened by vibrations or electron-pho ... | 1996 | 8889168 |
| modeling of the d1/d2 proteins and cofactors of the photosystem ii reaction center: implications for herbicide and bicarbonate binding. | a three-dimensional model of the photosystem ii (psii) reaction center from the cyanobacterium synechocystis sp. pcc 6803 was generated based on homology with the anoxygenic purple bacterial photosynthetic reaction centers of rhodobacter sphaeroides and rhodopseudomonas viridis, for which the x-ray crystallographic structures are available. the model was constructed with an alignment of d1 and d2 sequences with the l and m subunits of the bacterial reaction center, respectively, and by using as ... | 1996 | 8897606 |
| a model for the photosystem ii reaction center core including the structure of the primary donor p680. | for a detailed understanding of the function of photosystem ii (psii), a molecular structure is needed. the crystal structure has not yet been determined, but the psii reaction center proteins d1 and d2 show homology with the l and m subunits of the photosynthetic reaction center from purple bacteria. we have modeled important parts of the d1 and d2 proteins on the basis of the crystallographic structure of the reaction center from rhodopseudomonas viridis. the model contains the central core of ... | 1996 | 8931545 |
| deletion of a b800-850 light-harvesting complex in rhodospirillum molischianum dsm119 leads to "revertants" expressing a b800-820 complex: insights into pigment binding. | a b800-850 light-harvesting complex (also called lh2) deficient strain of rhodospirillum molischianum was constructed by replacing a portion of the lh2 gene cluster by a kanamycin resistance gene cartridge. the lh2 deficient strain was characterized spectroscopically and by southern blot analysis. surprisingly, pseudorevertants were obtained which express a b800-820 complex which could not be observed in the wild type. this b800-820 complex was isolated and characterized. it consists of an alpha ... | 1996 | 8639597 |
| expression of porin from rhodopseudomonas blastica in escherichia coli inclusion bodies and folding into exact native structure. | the homotrimeric membrane channel porin from rhodopseudomonas blastica was expressed without signal sequence in escherichia coli. the protein assembled in inclusion bodies in the cytosol, from which it could be recovered using urea and detergents. after purification by anion-exchange chromatography, the protein crystallized under wild-type conditions. the x-ray structure was determined at 2.2 angstroms resolution, and a comparison with the known wild-type structure showed that the recombinant po ... | 1996 | 8641415 |
| exciton delocalization in the antenna of purple bacteria: exciton spectrum calculations using z-ray data and experimental site inhomogeneity. | electron absorption and circular dichroism spectra of the peripheral light-harvesting complex (lh2) of photosynthetic purple bacteria were calculated taking into account the real-life spatial arrangement and experimental inhomogeneous broadening of bacteriochlorophyll molecules. it was shown that strong excitonic interactions between 18 bacteriochlorophyll molecules (bch1850) within the circular aggregate of the lh2 complex result in an exciton delocalization over all these pigment molecules. th ... | 1996 | 8654573 |
| the distance between bacterial species in sequence space. | despite the revolution caused by information from macromolecular sequences, the basis of bacterial classification remains the genus and the species. how do these terms relate to the variety of bacteria that exist on earth? in this paper, the inter- and intraspecies differences in amino acid sequence of several bacterial electron transport proteins, cytochromes c, and blue copper proteins are compared. for the soil and water organisms studied, bacterial species can be classed as "tight" when ther ... | 1996 | 8662021 |
| the synthesis and assembly of functional high and low light lh2 antenna complexes from rhodopseudomonas palustris in rhodobacter sphaeroides. | photosynthetic bacteria respond to lowered light intensity by increasing the level of the peripheral light-harvesting (lh2) complex. several species possess an additional mechanism, responding to variations in light conditions by making different types of lh2 complex. however, the study of these complexes in isolation and in the native membrane environment has not been possible. therefore two lh2 gene pairs from rhodopseudomonas palustris, associated, respectively, with high light (pucbaa) and l ... | 1996 | 8662765 |
| the antenna complexes of the purple non-sulfur photosynthetic bacterium rhodocyclus tenuis. structural and spectral characterization. | the photoreceptor complex (b885-rc) and the peripheral antenna complex (b800-860) were isolated from photosynthetic membranes of the purple non-sulfur bacterium rhodocyclus tenuis dsm 109 using a detergent combination of deriphate-160 and octyl glucoside and subsequent linear sucrose gradient centrifugation. the two complexes were characterized by room-temperature absorption, circular dichroism and fluorescence spectroscopy. the b800-860 complex has a more red-shifted b860 absorbance band. the a ... | 1996 | 8681949 |
| the conformation of the isoprenyl chain relative to the semiquinone head in the primary electron acceptor (qa) of higher plant psii (plastosemiquinone) differs from that in bacterial reaction centers (ubisemiquinone or menasemiquinone) by ca. 90 degrees. | the conformation and partial electron spin density distribution of the reduced primary electron acceptor (qa-), a plastosemiquinone-9 (pq-9-) anion radical, in photosystem ii protein complexes from spinach as well as free pq-9- in solution have been determined by epr and 1h endor spectroscopies. the data show that the conformation of the isoprenyl chain at c beta relative to the aromatic ring differs by 90 degrees for qa- in higher plant psii versus both types of bacterial reaction centers, rhod ... | 1996 | 8688432 |
| modelling for waste water treatment by rhodopseudomonas palustris y6 immobilized on fibre in a columnar bioreactor. | a kinetic model of continuous treatment of waste water by rhodopseudomonas palustris y6 immobilized on soft fibre in a columnar bioreaction system was established. good agreement was found between the model prediction and the experimental data from continuous operation [initial chemical oxygen demand (cod) concentration = 29.700 g/l] of the system. the optimum operational conditions for the maximum cod reduction capacity were investigated from the model prediction and the experimental data. the ... | 1996 | 8703436 |
| electron transfer dynamics of rhodopseudomonas viridis reaction centers with a modified binding site for the accessory bacteriochlorophyll. | femtosecond spectroscopy in combination with site-directed mutagenesis was used to study the influence of histidine l153 in primary electron transfer in the reaction center of rhodopseudomonas viridis. histidine was replaced by cysteine, glutamate, or leucine. the exchange to cysteine did not lead to significant changes in the primary reaction dynamics. in the case of the glutamate mutation, the decay of the excited electronic level of the special pair p* is slowed by a factor of 3. the exchange ... | 1996 | 8703929 |
| recognition of transmembrane alpha-helical segments with environmental profiles. | a method for assessing the environmental properties of membrane-spanning alpha-helical peptides in proteins has been proposed. the algorithm employs a set of environmental preference parameters derived for amino acid residues based on the analysis of the 3-d structures of membrane domains in bacteriorhodopsin and photoreaction centers rhodopseudomonas viridis and rhodobacter sphaeroides. the resulting 3-d-1-d scores for transmembrane segments are significantly different from those derived for al ... | 1996 | 8736492 |
| the crystal structure of the light-harvesting complex ii (b800-850) from rhodospirillum molischianum. | the light-harvesting complexes ii (lh-2s) are integral membrane proteins that form ring-like structures, oligomers of alpha beta-heterodimers, in the photosynthetic membranes of purple bacteria. they contain a large number of chromophores organized optimally for light absorption and rapid light energy migration. recently, the structure of the nonameric lh-2 of rhodopseudomonas acidophila has been determined; we report here the crystal structure of the octameric lh-2 from rhodospirillum molischia ... | 1996 | 8736556 |
| pigment-pigment interactions and energy transfer in the antenna complex of the photosynthetic bacterium rhodopseudomonas acidophila. | photosynthesis starts with the absorption of solar radiation by antenna pigment molecules. in purple bacteria these chromophores, (bacteriochlorophyll a and carotenoid) are embedded in the membrane; they are non-covalently bound to apoproteins which have the ability to modulate the chromophores' absorbing characteristics. the first structure of the bacterial antenna complex from rhodopseudomonas acidophila, strain 10050, shows a ring of nonameric symmetry. two concentric cylinders of apoproteins ... | 1996 | 8740367 |
| calculated coupling of electron and proton transfer in the photosynthetic reaction center of rhodopseudomonas viridis. | based on new rhodopseudomonas (rp.) viridis reaction center (rc) coordinates with a reliable structure of the secondary acceptor quinone (qb) site, a continuum dielectric model and finite difference technique have been used to identify clusters of electrostatically interacting ionizable residues. twenty-three residues within a distance of 25 a from qb (qb cluster) have been shown to be strongly electrostatically coupled to qb, either directly or indirectly. an analogous cluster of 24 residues is ... | 1996 | 8744288 |
| molecular analysis of the rhodobacter capsulatus b10 porin (porca) gene; purification and biochemical characterisation of the porin protein. | the pore-forming outer-membrane protein from rhodobacter (r.) capsulatus (wild-type b10 strain) was isolated and purified under non-denaturing conditions. the monomer unit of the isolated porin has a molecular mass of about 28 kda, as judged by sds-page, whereas the native protein migrates at 75 kda. this suggests that the native porin from r. capsulatus b10 exists in a trimeric form. the n-terminal amino acid sequence was used to design an oligonucleotide which was utilised to screen a pbluescr ... | 1996 | 9003311 |
| protein-detergent interactions in single crystals of membrane proteins studied by neutron crystallography. | the detergent micelles surrounding membrane protein molecules in single crystals can be investigated using neutron crystallography combined with h2o/d2o contrast variation. if the protein structure is known then the contrast variation method allows phases to be determined at a contrast where the detergent dominates the scattering. the application of various constraints allows the resulting scattering length density map to be realistically modeled. the method has been applied to two different for ... | 1996 | 9092456 |
| spectroscopic characterization of nitrosylheme in nitric oxide complexes of ferric and ferrous cytochrome c' from photosynthetic bacteria. | reactions of ferric and ferrous cytochromes c' from four photosynthetic bacteria (rhodobacter capsulatus atcc 11166, rhodopseudomonas palustris atcc 17001, rhodospirillum rubrum atcc 11170, and chromatium vinosum atcc 17899) with nitric oxide have been investigated by electronic absorption and electron paramagnetic resonance spectroscopies. the heme iron(iii) of these ferric cytochromes c' has been recently reported to be in a quantum mechanically admixed (s = 5/2, 3/2) state [fujii, s., yoshimu ... | 1996 | 8547347 |
| the structure of porin from paracoccus denitrificans at 3.1 a resolution. | the crystal structure of a non-specific porin from paracoccus denitrificans at 3.1 a resolution has been solved by molecular replacement using the porin from rhodopseudomonas blastica as the search model. paracoccus porin is very similar to other non-specific porins of known structure: a trimer of 16 stranded beta-barrels each with a central pore constricted by a long extracellular loop folding back against the barrel wall. the distinctive distribution of charged residues of this non-specific po ... | 1997 | 9119065 |
| an nmr study of the 7fe-8s ferredoxin from rhodopseudomonas palustris and reinterpretation of data on similar systems. | the oxidized 7fe-8s ferredoxin from rhodopseudomonas palustris is shown to possess a unique 1h nmr spectrum displaying at least one hyperfine-shifted beta-ch2 signal for each cysteine bound to the [3fe-4s] cluster. cosy and tocsy spectra and 1- and 2-dimensional noe experiments, in conjunction with a thorough reexamination of the 1h nmr data on similar systems, permitted the sequential assignment of all of the cysteine beta-ch2 protons even in the absence of the amino acid sequence. the sequenti ... | 1997 | 9132008 |
| molecular cloning and functional characterization of the paracoccus denitrificans porin. | bacterial porins facilitate the passive uptake of small solutes across the outer membrane of the cell. the channel properties and the primary structure of the porin from paracoccus denitrificans were investigated. as judged from single-channel conductance experiments, this porin forms trimeric pores that show no ion selectivity in potassium chloride solution, which indicates that the charges within or near the channel are balanced. based on peptide fragment sequence, the gene porg, which codes f ... | 1997 | 9151957 |
| apoprotein structure in the lh2 complex from rhodopseudomonas acidophila strain 10050: modular assembly and protein pigment interactions. | the refined structure of the peripheral light-harvesting complex from rhodopseudomonas acidophila strain 10050 reveals a membrane protein with protein-protein interactions in the trans-membrane region exclusively of a van der waals nature. the dominant factors in the formation of the complex appear to be extramembranous hydrogen bonds (suggesting that each apoprotein must achieve a fold close to its final structure in order to oligomerize), protein-pigment and pigment-pigment interactions within ... | 1997 | 9159480 |
| a cluster of bacterial genes for anaerobic benzene ring biodegradation. | a reductive benzoate pathway is the central conduit for the anaerobic biodegradation of aromatic pollutants and lignin monomers. benzene ring reduction requires a large input of energy and this metabolic capability has, so far, been reported only in bacteria. to determine the molecular basis for this environmentally important process, we cloned and analyzed genes required for the anaerobic degradation of benzoate and related compounds from the phototrophic bacterium, rhodopseudomonas palustris. ... | 1997 | 9177244 |
| molecular handling of photosynthetic proteins for molecular assembly construction. | methods of constructing proteins were examined with special reference to the molecular assembly using photosynthetic rcs as membrane proteins. molecular assemblies at the interfaces were studied by lb films, adsorption to the surface and reconstitution into liposomes and bilayer lipid membranes. the applications of biological specific ligands (recognition and binding), combinatorial chemical method, 2-d and 3-d order array assemblies and modification of protein molecules to make fusion proteins, ... | 1997 | 9204130 |
| 4-hydroxybenzoyl coenzyme a reductase (dehydroxylating) is required for anaerobic degradation of 4-hydroxybenzoate by rhodopseudomonas palustris and shares features with molybdenum-containing hydroxylases. | the anaerobic degradation of 4-hydroxybenzoate is initiated by the formation of 4-hydroxybenzoyl coenzyme a, with the next step proposed to be a dehydroxylation to benzoyl coenzyme a, the starting compound for a central pathway of aromatic compound ring reduction and cleavage. three open reading frames, divergently transcribed from the 4-hydroxybenzoate coenzyme a ligase gene, hbaa, were identified and sequenced from the phototrophic bacterium rhodopseudomonas palustris. these genes, named hbabc ... | 1997 | 9006014 |
| effect of pesticides on the diazotrophic growth and nitrogenase activity of purple nonsulfur bacteria. | 1997 | 9008058 | |
| very fast electron transfer from cytochrome to the bacterial photosynthetic reaction center at low temperature. | electron transfer from the proximal heme c-559 to the primary donor p has been studied in reaction centers of the photosynthetic bacterium rhodopseudomonas viridis in which the tyrosine residue l162 was replaced by threonine. in the wild type, when the two high-potential hemes of the tetraheme cytochrome are reduced before flash excitation, a rapid electron transfer (t1/2 = 190 ns) observed at ambient temperature disappears below 190 k. in the mutant, the reaction is partly maintained down to 8 ... | 1997 | 9013877 |
| anion binding to cytochrome c2: implications on protein-ion interactions in class i cytochromes c. | the binding of several inorganic and carboxylate anions to cytochrome c2 from rhodopseudomonas palustris has been investigated by monitoring the salt-induced changes in the redox potential of the heme, using an interpretative model based on the extended debye-hückel equation. most anions were found to interact specifically with the protein at one or multiple sites. binding constants to the oxidized protein in the range 10(1)-10(2) m-1 were determined from the anion concentration dependence of th ... | 1997 | 9056260 |
| cloning of dnak and dnaj homologous genes from a purple non-sulfur bacterium rhodopseudomonas species. | the dnak and dnaj genes were isolated as a cluster from a purple non-sulfur phototrophic bacterium, rhodopseudomonas species no. 7 by a polymerase chain reaction (pcr) based method. the deduced products of dnak (631 amino acids) and dnaj (379 amino acids) were 67% and 56% identical to the respective escherichia coli gene products. the functions of dnak and dnaj could be confirmed by complementation of the respective e. coli mutants. | 1997 | 9061015 |
| influence of asn/his l166 on the hydrogen-bonding pattern and redox potential of the primary donor of purple bacterial reaction centers. | the primary electron donor (p) of the photosynthetic reaction center (rc) from the purple bacterium rhodobacter (rb.) sphaeroides is constituted of two bacteriochlorophyll molecules in excitonic interaction. the c2 acetyl carbonyl group of one of the two bacteriochlorophyll molecules (pl), the one more closely associated with the l polypeptide subunit, is engaged in a hydrogen bond with histidine l168, while the other pi-conjugated carbonyl groups of p are free from such hydrogen-bonding interac ... | 1997 | 9062134 |
| transfer of the bacteriochlorophyll b-containing phototrophic bacteria rhodopseudomonas viridis and rhodopseudomonas sulfoviridis to the genus blastochloris gen. nov. | the phylogenetic positions of the bacteriochlorophyll (bchl) b-producing budding phototrophic bacteria rhodopseudomonas viridis and rhodopseudomonas sulfoviridis were studied on the basis of 16s rrna gene sequence information. these bacteria formed a tight cluster with the genus rhodoplanes as a sister group within the alpha-2 subgroup of the proteobacteria. genomic dna-dna hybridization assays showed that r. viridis and r. sulfoviridis were closely related but were different species. creation o ... | 1997 | 8995826 |
| structural and functional analysis of the phosphoenolpyruvate carboxylase gene from the purple nonsulfur bacterium rhodopseudomonas palustris no. 7. | the ppc gene, encoding phosphoenolpyruvate carboxylase (pepc), from rhodopseudomonas palustris no. 7 was cloned and sequenced. primer extension analysis identified a transcriptional start site 42 bp upstream of the ppc initiation codon. an r. palustris no. 7 pepc-deficient strain showed a slower doubling time compared with the wild-type strain either anaerobically in the light or aerobically in the dark, when pyruvate was used as a carbon source. | 1997 | 9244286 |
| reductive dehalogenation of halocarboxylic acids by the phototrophic genera rhodospirillum and rhodopseudomonas. | type strains of the purple nonsulfur species rhodospirillum rubrum, rhodospirillum photometricum, and rhodopseudomonas palustris grew phototrophically on a number of two- and three-carbon halocarboxylic acids in the presence of co2, by reductive dehalogenation and assimilation of the resulting acid. strains of each of these species were able to grow on chloroacetic, 2-bromopropionic, 2-chloropropionic, and 3-chloropropionic acids at a concentration of 2 mm. only r. palustris dsm 123 was able to ... | 1997 | 9251226 |
| the role of betaarg-10 in the b800 bacteriochlorophyll and carotenoid pigment environment within the light-harvesting lh2 complex of rhodobacter sphaeroides. | previous work has suggested that the betaarg-10 residue forms part of the binding site for the b800 bacteriochlorophyll in the lh2 complex of rhodobactersphaeroides [crielaard, w., visschers, r. w., fowler, g. j. s., van grondelle, r., hellingwerf, k. j., hunter, c. n. (1994) biochim. biophys. acta1183, 473-482], and this is consistent with the x-ray crystallographic data that have been subsequently obtained for the related lh2 complex from rhodopseudomonas acidophila [mcdermott, g., prince, s. ... | 1997 | 9287171 |
| [rieske protein--a component of transmembrane cytochrome complexes]. | 1997 | 9289727 | |
| membrane lipids of rhodopseudomonas viridis. | in search of the precyanobacterial origin of the typical thylakoid lipids found in cyanobacteria and chloroplasts, we analyzed the polar lipids of the anaerobic phototrophic bacterium rhodopseudomonas viridis. glycolipids (monogalactosyl-, digalactosyl- and glucuronosyl diacylglycerol), phospholipids (phosphatidyl choline, -ethanolamine, -glycerol and cardiolipin) and an ornithine lipid were isolated and identified by nmr (1h, 13c, 31p) and mass spectrometry. positional distribution and pairing ... | 1997 | 9295159 |
| characterization of porin from roseobacter denitrificans. | porin from roseobacter denitrificans was isolated and purified to homogeneity. the pore characteristics from this marine bacterium were compared to those of its phylogenetically closely related freshwater bacteria rhodobacter capsulatus, rhodobacter sphaeroides and rhodopseudomonas blastica. the porin formed weakly cation-selective, general diffusion pores in lipid bilayer membranes. high transmembrane potentials caused channel closing in steps that were of one or two thirds of the initial on-st ... | 1997 | 9298192 |
| the coupling of light-induced electron transfer and proton uptake as derived from crystal structures of reaction centres from rhodopseudomonas viridis modified at the binding site of the secondary quinone, qb. | in a reaction of central importance to the energetics of photosynthetic bacteria, light-induced electron transfer in the reaction centre (rc) is coupled to the uptake of protons from the cytoplasm at the binding site of the secondary quinone (qb). in the original structure of the rc from rhodopseudomonas viridis (pdb entry code 1prc), the qb site was poorly defined because in the standard rc crystals it was only approximately 30% occupied with ubiquinone-9 (uq9). we report here the structural ch ... | 1997 | 9351808 |
| fluorescence and photobleaching dynamics of single light-harvesting complexes. | single light-harvesting complexes lh-2 from rhodopseudomonas acidophila were immobilized on various charged surfaces under physiological conditions. polarized light experiments showed that the complexes were situated on the surface as nearly upright cylinders. their fluorescence lifetimes and photobleaching properties were obtained by using a confocal fluorescence microscope with picosecond time resolution. initially all molecules fluoresced with a lifetime of 1 +/- 0.2 ns, similar to the bulk v ... | 1997 | 9380686 |
| redox thermodynamics of the native and alkaline forms of eukaryotic and bacterial class i cytochromes c. | the reduction potentials of beef heart cytochrome c and cytochromes c2 from rhodopseudomonas palustris, rhodobacter sphaeroides, and rhodobacter capsulatus were measured through direct electrochemistry at a surface-modified gold electrode as a function of temperature in nonisothermal experiments carried out at neutral and alkaline ph values. the thermodynamic parameters for protein reduction (deltas degrees rc and deltah degrees rc) were determined for the native and alkaline conformers. enthalp ... | 1997 | 9405059 |
| influence of the protein binding site on the absorption properties of the monomeric bacteriochlorophyll in rhodobacter sphaeroides lh2 complex. | resonance raman spectroscopy was performed on peripheral light-harvesting proteins from rhodobacter sphaeroides in which the residue betaarg-10 has been modified by site-selected mutagenesis. we show that this residue is indeed involved (as proposed by x-ray crystallographic studies on the lh2 complex from rhodopseudomonas acidophila), in an h-bond with the acetyl carbonyl of the 800 nm-absorbing bchl in these proteins (b800), and that the presence of such an h-bond induces a ca. 10 nm red shift ... | 1997 | 9405063 |
| nucleotide sequences of genes coding for photosynthetic reaction centers and light-harvesting proteins of acidiphilium rubrum and related aerobic acidophilic bacteria. | the nucleotide sequences of the puf operons of the zn-bacteriochlorophyll a (zn-bchl a)-containing photosynthetic aerobic bacteria, acidiphilium rubrum and acidiphilium angustum, were determined. the nucleotide sequences of the pufl and -m of acidiphilium cryptum, acidiphilium multivorum, and acidiphilium organovorum were also determined. the puf operons of a. rubrum and a. angustum contained pufb, -a, -l, -m, and -c as seen in other purple bacteria with an unknown gene directly upstream of pufb ... | 1997 | 9435141 |
| in search of a bacterial species definition. | the bacterial species concept was examined within the framework of plant and animal associated alpha-2 proteobacteria, taking into consideration the phylogenetic, taxonomic and biological approaches as well as the microbiologists' perception. the virtue of the phylogenetic approach is that it gives an evolutionary perspective of the bacterial lineage; however the methods used possess low resolution for defining species located at the terminal branches of the phylogenetic trees. the merit of the ... | 1997 | 9458988 |
| the structure and function of the lh2 (b800-850) complex from the purple photosynthetic bacterium rhodopseudomonas acidophila strain 10050. | 1997 | 9481143 | |
| efficient exchange of the primary quinone acceptor q(a) in isolated reaction centers of rhodopseudomonas viridis. | a key step in the conversion of solar energy into chemical energy by photosynthetic reaction centers (rcs) occurs at the level of the two quinones, q(a) and q(b), where electron transfer couples to proton transfer. a great deal of our understanding of the mechanisms of these coupled reactions relies on the seminal work of okamura et al. [okamura, m. y., isaacson, r. a., & feher, g. (1975) proc. natl. acad. sci. usa 88, 3491-3495], who were able to extract with detergents the firmly bound ubiquin ... | 1997 | 11038584 |
| morphological and compositional shifts in an experimental bacterial community influenced by protists with contrasting feeding modes. | in a two-stage continuous-flow system, we studied the impacts of different protozoan feeding modes on the morphology and taxonomic structure of mixed bacterial consortia, which were utilizing organic carbon released by a pure culture of a rhodomonas sp. grown on inorganic medium in the first stage of the system. two of three second stages operated in parallel were inoculated by a bacterivorous flagellate, bodo saltans, and an algivorous ciliate, urotricha furcata, respectively. the third vessel ... | 1997 | 16535515 |
| [isolation and identification of rhodopseudomonas acidophila from fujian province, china]. | a strain p301 of gram negative purple nonsulfur bacterium was isolated from the ditch's mud collected in fuzhou, fujian. the cells are rod-shaped. multiplication occur by budding without stalk formation. growth optimum ph is 5.0-5.7. no growth factors required. the cells contain bacteriochlorophyll a. the photosynthetic membrane system consists of parallel lamellae. according to bergery's manual of determinative bacteriology, 8th ed. (1974) and 9th ed. (1994), the strain was identified to be rho ... | 1998 | 12549405 |
| electrostatic interactions at the donor side of the photosynthetic reaction center of rhodopseudomonas viridis. | the photosynthetic reaction center of rhodopseudomonas viridis, a purple bacterium, contains a tetraheme cytochrome subunit. after its photoinduced oxidation, the primary donor, p, is reduced by the nearby heme (c559) of the tetraheme subunit in about 200 ns. this heme, in turn, is reduced by another heme (c556) of the subunit in about 2 micro(s). the midpoint potentials of p, c559, and c556 are known to be +500, +380, and +320 mv, respectively. the reduction kinetics of p+ are strongly biphasic ... | 1998 | 9799492 |
| basis for monomer stabilization in rhodopseudomonas palustris cytochrome c' derived from the crystal structure. | the crystal structure of an unusual monomeric cytochrome c' from rhodopseudomonas palustris (rpcp) has been determined at 2.3 a resolution. rpcp has the four-helix (helices a, b, c and d) bundle structure similar to dimeric cytochromes c'. however the amino acid composition of the surface of helices a and b in rpcp is remarkably different from that of the dimeric cytochromes c'. this surface forms the dimer interface in the latter proteins. rpcp has seven charged residues on this surface contrar ... | 1998 | 9826513 |
| 1h nmr study of the reduced cytochrome c' from rhodopseudomonas palustris containing a high-spin iron(ii) heme moiety. | the assignment of the hyperfine shifted signals of the reduced cytochrome c' from rhodopseudomonas palustris has been obtained through saturation transfer experiments with assigned signals of the high-spin oxidized protein and through tailored experiments to reveal proton-proton dipolar connectivities in paramagnetic molecules. the peculiar shift pattern consisting of the 1-, 8-, and 5-methyl signals shifted upfield and the 3-methyl signal downfield, which is shared by all cytochromes c' so far ... | 1998 | 11670644 |
| characterization of gas transfer and mixing in a bubble column equipped with a rubber membrane diffuser | gas transfer and mixing were characterized in a 32-l bubble column reactor equipped with a commercially available rubber membrane diffuser. the performance of the membrane diffuser indicates that the slits in the membrane are best described as holes with elastic lids, acting as valves cutting off bubbles from the gas stream. the membrane diffuser thus functions as a one-way valve preventing backflow of liquid. our design of the bottom plate of the reactor enabled us to optimize the aeration by c ... | 1998 | 10099301 |
| energetics of electron-transfer and protonation reactions of the quinones in the photosynthetic reaction center of rhodopseudomonas viridis. | the electron-transfer reactions involving the quinones in the bacterial photosynthetic reaction center (brc) are coupled to a proton uptake by the brc. in this study, we calculated the energies of the different states of the brc occurring during these electron-transfer and protonation reactions by an electrostatic model. we considered the possibility that titratable groups of the brc can change their protonation during these reactions. the protonation probabilities of titratable groups were obta ... | 1998 | 9485397 |
| the cytochrome subunit structure in the photosynthetic reaction center of chromatium minutissimum. | gel-electrophoretic assay revealed that the photosynthetic reaction center (rc) of chromatium minutissimum, in contrast to the well-known rc rhodopseudomonas viridis, consists of five rather than four subunits with molecular masses of 37, 34, 25, 19, and 17 kda. the 37- and 19-kda subunits are stained with tetramethylbenzidine for the cytochrome c hemes. absorption spectra show that the concentration of reduced cytochromes in the c. minutissimum rc poised at redox potential of -150 mv (fully red ... | 1998 | 9490013 |
| 4-hydroxybenzoyl-coa reductase (dehydroxylating) from the denitrifying bacterium thauera aromatica--prosthetic groups, electron donor, and genes of a member of the molybdenum-flavin-iron-sulfur proteins. | 4-hydroxybenzoyl-coa reductase catalyzes an important reaction in the anaerobic metabolism of phenolic compounds, i.e. the reductive removal of an aromatic hydroxyl group. the prosthetic groups and the natural electron donor of the enzyme were investigated and the genes were cloned and sequenced. the enzyme is a molybdenum-flavin-iron-sulfur protein of subunit composition of alpha2beta2gamma2. it contains approximately 1.3 flavin nucleotide, probably fad, 1.9 mo, 15 fe, and 12.5 acid-labile sulf ... | 1998 | 9490068 |
| low-temperature electron transfer from cytochrome to the special pair in rhodopseudomonas viridis: role of the l162 residue. | electron transfer from the tetraheme cytochrome c to the special pair of bacteriochlorophylls (p) has been studied by flash absorption spectroscopy in reaction centers isolated from seven strains of the photosynthetic purple bacterium rhodopseudomonas viridis, where the residue l162, located between the proximal heme c-559 and p, is y (wild type), f, w, g, m, t, or l. measurements were performed between 294 k and 8 k, under redox conditions in which the two high-potential hemes of the cytochrome ... | 1998 | 9512015 |
| calculation of electron transfer reorganization energies using the finite difference poisson-boltzmann model. | a description is given of a method to calculate the electron transfer reorganization energy (lambda) in proteins using the linear or nonlinear poisson-boltzmann (pb) equation. finite difference solutions to the linear pb equation are then used to calculate lambda for intramolecular electron transfer reactions in the photosynthetic reaction center from rhodopseudomonas viridis and the ruthenated heme proteins cytochrome c, myoglobin, and cytochrome b and for intermolecular electron transfer betwe ... | 1998 | 9512022 |
| redox properties of an h-subunit-depleted photosynthetic reaction center from rhodopseudomonas viridis. | recently, we reported that a h-subunit-depleted photosynthetic reaction center (rc-h) was purified from purple nonsulfer photosynthetic bacterium rhodopseudomonas viridis (rps. viridis) using a strong detergent sodium alkyl ether sulfate. we compared the redox properties of a native photosynthetic reaction center (rc) and rc-h of rps. viridis. in rc-h prepared by our method, secondary quinone (qb) was removed while primary quinone (qa) was retained. absorption spectrum of rc-h was similar to tha ... | 1998 | 9518612 |
| crystallization of phycoerythrin 545 of rhodomonas lens using detergents and unusual additives. | phycoerythrin 545 from the cryptomonad alga, rhodomonas lens, has been crystallized under a wide variety of conditions. although this type of photosynthetic light-harvesting protein is water soluble, detergents were always required for crystallization. the crystals were typically poorly ordered, or ordered in only two dimensions. however, crystals that were well-ordered in three dimensions could be obtained under two different conditions. both used polyethylene glycol as precipitant and the dete ... | 1998 | 9541389 |
| [spatial structure of the photosynthetic bacterium rhodopseudomonas viridis b1015 complex]. | 1998 | 9541791 | |
| energy transfers in the b808-866 antenna from the green bacterium chloroflexus aurantiacus. | energy transfers within the b808-866 bchl a antenna in chlorosome-membrane complexes from the green photosynthetic bacterium chloroflexus aurantiacus were studied in two-color pump-probe experiments at room temperature. the steady-state spectroscopy and protein sequence of the b808-866 complex are reminiscent of well-studied lh2 antennas from purple bacteria. b808-->b866 energy transfers occur with approximately 2 ps kinetics; this is slower by a factor of approximately 2 than b800-->b850 energy ... | 1998 | 9545065 |
| sodium alkyl ether sulfate preparative electrophoresis for the preparation of reaction centers without h-subunit from rhodopseudomonas viridis. | sodium alkyl ether sulfate (aes), an analog of sodium dodecyl sulfate (sds) was used in polyacrylamide gel electrophoresis (page) for the partial decomposition of the photosynthetic reaction center (rc) of rhodopseudomonas viridis. unlike sds, aes did not completely dissociate rc into its subunits but selectively detached h-subunit from rc to give rc(-h) without losing the spectroscopic nature of rc. for the denaturation of rc(-h), aes was found to be as mild as 3-[3-cholamidopropyl)dimethylammo ... | 1998 | 9548298 |
| identification of the upper exciton component of the b850 bacteriochlorophylls of the lh2 antenna complex, using a b800-free mutant of rhodobacter sphaeroides. | in this paper, we report the circular dichroism (cd) spectra of two types of lh2-only mutants of rhodobacter sphaeroides. in the first, only the wild type lh2 is present, while i the second, the b800 binding site of lh2 has been either destabilized or removed. for the first time, we have identified a band in the cd spectrum of lh2, located at approximately 780 nm, that can be ascribed to the high exciton component of the b850 band. the experimental spectra have been modeled by theoretical calcul ... | 1998 | 9548732 |
| projection map of the reaction center-light harvesting 1 complex from rhodopseudomonas viridis at 10 a resolution. | the photosynthetic reaction center-light harvesting 1 complex from rhodopseudomonas viridis was purified and reconstituted into two-dimensional crystals. the single-layered crystalline sheets with lattice parameters a=b=133.3 a and gamma=120 degrees were investigated by electron cryo-microscopy and the projection map at 10 a resolution was calculated. the opening diameter of the light-harvesting ring of 72 a is sufficient to allow slight movement of the reaction center within the ring. based on ... | 1998 | 9563522 |
| structures of homologous composite transposons carrying cbaabc genes from europe and north america. | is1071 is a class ii transposable element carrying a tnpa gene related to the transposase genes of the tn3 family. copies of is1071 that are conserved with more than 99% nucleotide sequence identity have been found as direct repeats flanking a remarkable variety of catabolic gene sequences worldwide. the sequences of chlorobenzoate catabolic transposons found on pbrc60 (tn5271) in niagara falls, n.y., and on pcpe3 in bologna, italy, show that these transposons were formed from highly homologous ... | 1998 | 9572977 |
| 2-ketocyclohexanecarboxyl coenzyme a hydrolase, the ring cleavage enzyme required for anaerobic benzoate degradation by rhodopseudomonas palustris. | 2-ketocyclohexanecarboxyl coenzyme a (2-ketochc-coa) hydrolase has been proposed to catalyze an unusual hydrolytic ring cleavage reaction as the last unique step in the pathway of anaerobic benzoate degradation by bacteria. this enzyme was purified from the phototrophic bacterium rhodopseudomonas palustris by sequential q-sepharose, phenyl-sepharose, gel filtration, and hydroxyapatite chromatography. the sequence of the 25 n-terminal amino acids of the purified hydrolase was identical to the ded ... | 1998 | 9573182 |
| genotypic characterization of bradyrhizobium strains nodulating endemic woody legumes of the canary islands by pcr-restriction fragment length polymorphism analysis of genes encoding 16s rrna (16s rdna) and 16s-23s rdna intergenic spacers, repetitive extragenic palindromic pcr genomic fingerprinting, and partial 16s rdna sequencing. | we present a phylogenetic analysis of nine strains of symbiotic nitrogen-fixing bacteria isolated from nodules of tagasaste (chamaecytisus proliferus) and other endemic woody legumes of the canary islands, spain. these and several reference strains were characterized genotypically at different levels of taxonomic resolution by computer-assisted analysis of 16s ribosomal dna (rdna) pcr-restriction fragment length polymorphisms (pcr-rflps), 16s-23s rdna intergenic spacer (igs) rflps, and repetitiv ... | 1998 | 9603820 |
| cloning, sequencing, and characterization of the reca gene from rhodopseudomonas viridis and construction of a reca strain. | a recombination-deficient strain of the phototrophic bacterium rhodopseudomonas viridis was constructed for the homologous expression of modified photosynthetic reaction center genes. the r. viridis reca gene was cloned and subsequently deleted from the r. viridis genome. the cloned r. viridis reca gene shows high identity to known reca genes and was able to complement the rec- phenotype of a rhizobium meliloti reca strain. the constructed r. viridis reca strain showed the general rec- phenotype ... | 1998 | 9620976 |
| aerobic chemolithoautotrophic growth and rubisco function in rhodobacter capsulatus and a spontaneous gain of function mutant of rhodobacter sphaeroides. | photosynthetic prokaryotes that assimilate co2 under anoxic conditions may also grow chemolithoautotrophically with o2 as the electron acceptor. among the nonsulfur purple bacteria, two species (rhodobacter capsulatus and rhodopseudomonas acidophilus), exhibit aerobic chemolithoautotrophic growth with hydrogen as the electron donor. although wild-type strains of rhodobacter sphaeroides grow poorly, if at all, with hydrogen plus oxygen in the dark, we report here the isolation of a spontaneous mu ... | 1998 | 9639598 |
| crystallising the lh1-rc "core" complex of purple bacteria. | 1998 | 9649835 | |
| purification and primary structure analysis of two cytochrome c2 isozymes from the purple phototrophic bacterium rhodospirillum centenum. | the isolation and amino acid sequences of two cytochromes c-552 from the thermotolerant bacterium rhodospirillum (r.) centenum have been determined. they are very similar to one another with 85% identity. they are homologous to the cytochromes c2 from purple bacteria with approximately 67% identity to that from rhodopseudomonas (rps.) palustris compared to only 42% identity with others of the c2 subclass. in addition, they share an unusual six-residue insertion with rps. palustris cytochrome c2 ... | 1998 | 9659396 |
| model for the light-harvesting complex i (b875) of rhodobacter sphaeroides. | the light-harvesting complex i (lh-i) of rhodobacter sphaeroides has been modeled computationally as a hexadecamer of alphabeta-heterodimers, based on a close homology of the heterodimer to that of light-harvesting complex ii (lh-ii) of rhodospirillum molischianum. the resulting lh-i structure yields an electron density projection map that is in agreement with an 8.5-a resolution electron microscopic projection map for the highly homologous lh-i of rs. rubrum. a complex of the modeled lh-i with ... | 1998 | 9675170 |
| a novel, non-statistical method for predicting breaks in transmembrane helices. | we have developed a novel, non-statistical procedure for predicting possible breaks in transmembrane helices based on energy calculations. the procedure consists of stepwise elongation of the 'core' helical fragment determined by consensus results of several available prediction procedures. at each step, we calculate the conformational energies corresponding to the regular 'frozen' helical conformer of the 'core' fragment elongated by two flanking residues, e(alpha), as well as those to several ... | 1998 | 9680189 |
| porin mutants with new channel properties. | the general diffusion porin from rhodopseudomonas blastica was produced in large amounts in escherichia coli inclusion bodies and (re)natured to the exact native structure. here, we report on 13 mutants at the pore eyelet giving rise to new diffusion properties as measured in planar lipid bilayer experiments. the crystal structures of seven of these mutants were established. the effects of charge-modifying mutations at the pore eyelet are consistent with the known selectivity for cations. deleti ... | 1998 | 9684893 |
| interaction site for soluble cytochromes on the tetraheme cytochrome subunit bound to the bacterial photosynthetic reaction center mapped by site-directed mutagenesis. | the crystallographic structure of the blastochloris (formerly called rhodopseudomonas) viridis tetraheme cytochrome subunit bound to the photosynthetic reaction center (rc) suggests that all four hemes are located close enough to the surface of the protein to accept electrons from soluble cytochrome c2. to identify experimentally the site of this reaction we prepared site-directed mutants of rubrivivax gelatinosus rcs with surface charge substitutions in the bound cytochrome subunit and studied ... | 1998 | 9718296 |
| three cdg operons control cellular turnover of cyclic di-gmp in acetobacter xylinum: genetic organization and occurrence of conserved domains in isoenzymes. | cyclic di-gmp (c-di-gmp) is the specific nucleotide regulator of beta-1,4-glucan (cellulose) synthase in acetobacter xylinum. the enzymes controlling turnover of c-di-gmp are diguanylate cyclase (dgc), which catalyzes its formation, and phosphodiesterase a (pdea), which catalyzes its degradation. following biochemical purification of dgc and pdea, genes encoding isoforms of these enzymes have been isolated and found to be located on three distinct yet highly homologous operons for cyclic diguany ... | 1998 | 9721278 |
| cyclohexa-1,5-diene-1-carbonyl-coa hydratase [corrected], an enzyme involved in anaerobic metabolism of benzoyl-coa in the denitrifying bacterium thauera aromatica. | many aromatic compounds can be metabolized by bacteria under anoxic conditions via benzoyl-coa as the common intermediate. the central pathway of benzoyl-coa metabolism is initiated by an atp-driven reduction of the aromatic ring producing cyclohexa-1,5-diene-1-carbonyl-coa. the 1,5-dienoyl-coa intermediate is thought to be transformed to 6-hydroxycyclohex-1-ene-1-carbonyl-coa by a specific dienoyl-coa hydratase catalyzing the formal addition of water to one of the double bonds. this dienoyl-coa ... | 1998 | 9738901 |
| resonance raman and infrared spectral studies on radical anions of model photosynthetic reaction center quinones (naphthoquinone derivatives). | quinones play a vital role in the processes of electron transfer in bacterial photosynthetic reaction centers. it is of interest to investigate photochemical reactions involving quinones with a view to elucidate structure-function relationships in biological processes. resonance raman and ftir spectra of electrochemically generated radical anions of 2-methyl-1,4-naphthoquinone, and 2-methyl-3-phytyl-1,4-naphthoquinone, also known as vitamin k3 and vitamin k1, respectively, (model compound for qa ... | 1998 | 9745901 |
| genes coding for the benzoyl-coa pathway of anaerobic aromatic metabolism in the bacterium thauera aromatica. | many aromatic compounds are anaerobically oxidized to co2 via benzoyl-coa as the common aromatic intermediate. in thauera aromatica, the central benzoyl-coa pathway comprises the atp-driven two-electron reduction of the benzene ring; this reaction uses a ferredoxin as electron donor and is catalyzed by benzoyl-coa reductase. the first intermediate, cyclohex-1,5-diene-1-carboxyl-coa, is subsequently hydrated by dienoyl-coa hydratase to 6-hydroxycyclohex-1-ene-1-carboxyl-coa. formation of the main ... | 1998 | 9746358 |