| fimbriation in gliding bacteria. | of twenty-two strains of gliding prokaryotes examined, all but three were found to possess polar fimbriae. fimbriae were not observed on two gliders, while chloroflexus aurantiacus bore abundant peritrichous fimbriae. in some gliding bacteria, fimbriae were associated with 'holes' surrounded by an electron-transparent collar bearing 12 spike-like projections. | 1977 | 407994 |
| uncultivated cyanobacteria, chloroflexus-like inhabitants, and spirochete-like inhabitants of a hot spring microbial mat. | analysis of 16s rrna sequences retrieved as cdna (16s rcdna) from the octopus spring cyanobacterial mat has permitted phylogenetic characterization of some uncultivated community members, expanding our knowledge or diversity within this microbial community. two new cyanobacterial 16s rrna sequences were discovered, raising to four the number of cyanobacterial sequence types known to occur in the mat. none of the sequences found is that of the cultivated thermophilic cyanobacterium synechococcus ... | 1992 | 1282313 |
| malate dehydrogenase from chlorobium vibrioforme, chlorobium tepidum, and heliobacterium gestii: purification, characterization, and investigation of dinucleotide binding by dehydrogenases by use of empirical methods of protein sequence analysis. | malate dehydrogenase (mdh; ec 1.1.1.37) from strain ncib 8327 of the green sulfur bacterium chlorobium vibrioforme was purified to homogeneity by triazine dye affinity chromatography followed by gel filtration. purification of mdh gave an approximately 1,000-fold increase in specific activity and recoveries of typically 15 to 20%. the criteria of purity were single bands on sodium dodecyl sulfate (sds) and nondenaturing polyacrylamide electrophoresis (page) and the detection of a single n termin ... | 1992 | 1735722 |
| photosynthetic sulfide oxidation by chloroflexus aurantiacus, a filamentous, photosynthetic, gliding bacterium. | chloroflexus, a newly described genus of filamentous, photosynthetic, gliding bacteria, oxidizes sulfide anaerobically under photoautotrophic or photoheterotrophic growh conditions and deposits elemental sulfur outside the cell. the formation of sulfur granules outside the cell supports the idea that this organism is related to the green sulfur bacteria (chlorobiaceae). | 1975 | 1092670 |
| bacteriochlorophyll cs, a new bacteriochlorophyll from chloroflexus aurantiacus. | from four strains of the gliding phototrophic bacterium chloroflexus aurantiacus, the as yet unknown bacteriochlorophyll cs was isolated in addition to small amounts of the known bacteriochlorophyll ap. the new bacteriochlorophyll cs is the main photosynthetic pigment of these organisms under the growth conditions used. it is different from the known bacteriochlorophylls c, as could be shown unequivocally by chromatographic examinations. evidence for the structure of the new bacteriochlorophyll ... | 1978 | 697505 |
| gene encoding the 5.7-kilodalton chlorosome protein of chloroflexus aurantiacus: regulated message levels and a predicted carboxy-terminal protein extension. | the major light-harvesting pigment of the green filamentous bacterium chloroflexus aurantiacus is bacteriochlorophyll (bchl) c, localized in chlorosomes attached to the inner surface of the cytoplasmic membrane. chlorosomes consist of four polypeptides and associated pigments and lipids. previous studies of the inducible assembly of the photosynthetic apparatus had indicated that the major chlorosomal polypeptides are present as high-molecular-weight aggregates before the appearance of mature ch ... | 1990 | 2376566 |
| adaptation by hot spring phototrophs to reduced light intensities. | photosynthesis was measured by the 14c method on natural as well as low light adapted populations of chloroflexus (a photosynthetic bacterium) and synechococcus (a blue-green alga) from hot springs in yellowstone national park (wyoming u.s.a.), to test the ability of these phototrophs to photosynthesize at a variety of light intensities. the herbicide 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (dcmu) was used to distinguish uptake of the blue-green alga from that of the photosynthetic bacterium, w ... | 1977 | 407880 |
| [fine structure of chloroflexus aurantiacus var. mesophilus (nom. prof.) grown in the light under aerobic and anaerobic conditions]. | the fine structure was studied in two mesophilic strains of chloroflexus aurantiacus var. mesophilus (nom. prof.): kn-4 and br-1. trichomes are covered with a mucous fibrillar sheath which is more developed in the kn-4 strain. photosynthetic structures, "chlorobium-vesicles", are located at the periphery of the cells of both strains. the structure of the cell was is typical of gram-negative microorganisms. by their electron density and dimensions, inner cytoplasmic structures are identified as p ... | 1977 | 407429 |
| [characteristics of filamentous phototrophic bacteria from freshwater lakes]. | filamentous phototrophic bacteria were isolated in pure cultures from fresh-water stratified lakes, and identified as chlorobacteria. the photosynthesizing apparatus of these bacteria is chlorobium-vesicules, the main pigment is bacteriochlorophyll c. the bacteria do not require reduced compounds of sulphur; they are capable of anaerobic photosynthesis on organic compounds or grow under aerobic conditions in the light or in the darkness. they are mesophilic (optimum temperature is 25 degrees c); ... | 1975 | 126349 |
| evolutionary relationships between "q-type" photosynthetic reaction centres: hypothesis-testing using parsimony. | hypotheses concerning the evolutionary relationships between "q-type" photosynthetic reaction centres are tested using amino acid parsimony analysis of subunit sequences and an alignment based on dot matrix comparisons. strong evidence is found for independent gene duplications having produced the l and m subunits of the photosynthetic purple bacterial reaction centre and d1 and d2 of photosystem-ii. much support is also found for the l and m subunits of the green filamentous bacterium chlorofle ... | 1990 | 2246901 |
| selective solubilization of chlorosome proteins in chloroflexus aurantiacus. | proteins were solubilized selectively from chlorosomes of chloroflexus aurantiacus by electrophoretic gel filtration according to griebenow et al. whereas the 11 kda and 18 kda proteins were extracted almost completely, the remaining modified chlorosomes contained high amounts of pigment and c-protein. it was concluded that the c-protein in contradiction to the publication by griebenow et al. is indeed localized in the interior of chloroflexus chlorosomes. | 1990 | 2199213 |
| two-dimensional crystallization of reaction centers from chloroflexus aurantiacus. | two-dimensional crystals of photosynthetic reaction centers from chloroflexus aurantiacus were obtained from protein-lipid-detergent micelles by detergent dialysis. the size of crystals was up to 2 microns. some of them were multilayered crystals. however, other crystal forms were also observed. preliminary image processing analysis showed that crystals of one crystal form referred to two-sided plane group p2 and had the following unit cell parameters: a = 17.6 nm, b = 18.0 nm, gamma = 84 degree ... | 1990 | 2194827 |
| distribution of phototrophic microbes in the flat laminated microbial mat at laguna figueroa, baja california, mexico. | the microbial mat community in the saltmarsh/evaporate flat interface at laguna figueroa involved in the deposition of laminated sediments was investigated. pigment analysis, light microscopy and transmission electron microscopy were used to determine the relative abundance and distribution of phototrophic species. the community is vertically stratified into four distinct phototrophic populations. the layering could be distinguished by pigment and species composition. the two layers closest to t ... | 1990 | 2108737 |
| resonance raman studies on the structure of bacteriochlorophyll c in chlorosomes from chloroflexus aurantiacus. | resonance raman spectra of chlorosomes isolated from the thermophilic green photosynthetic bacterium chloroflexus aurantiacus have been obtained with several excitation wavelengths from 441.6 to 514.5 nm. resonance raman spectra of bacteriochlorophyll (bchl) c isolated from c. aurantiacus cells have also been observed. the c=c stretching frequencies of bchl c in the chlorosomes were found to be at 1,556 (strong) and 1,544 (shoulder) cm-1, which correspond to those expected for the 5-coordinated ... | 1990 | 2081732 |
| [study of the structure of the photosynthetic reaction center of the green thermophilic bacteria chloroflexus aurantiacus]. | analysis of the chloroflexus aurantiacus reaction centre (rc) using both protein and recombinant dna techniques resulted in determination of its polypeptide composition and the primary structures of its two subunits. a model of the polypeptide chains' folding in the membrane is suggested based on: i) homology between l- and m-subunits of chloroflexus aurantiacus rc and their counterparts in purple bacteria; ii) comparison of their hydropathy plots, and iii) data on the tertiary structures of pur ... | 1990 | 2080929 |
| bacteriochlorophyll c formation via the c5 pathway of 5-aminolevulinic acid synthesis in chloroflexus aurantiacus. | biosynthesis of 5-aminolevulinic acid (ala) in chloroflexus aurantiacus, a thermophilic bacterium forming bacteriochlorophyll c, is shown to proceed via the c5 pathway by demonstrating (1) the specific labeling of its chlorin ring with [1 - 13c]glutamate and (2) the enzyme activity to produce ala from glutamate in a cell-free extract. from the phylogenetic distribution it is suggested that ala synthetase distributed in some aerobic eubacteria could be monophyletic in origin. | 1991 | 2015889 |
| functioning of quinone acceptors in the reaction center of the green photosynthetic bacterium chloroflexus aurantiacus. | the photosynthetic reaction centers (rc) of the green bacterium chloroflexus aurantiacus have been investigated by spectral and electrometrical methods. in these reaction centers, the secondary quinone was found to be reconstituted by the addition of ubiquinone-10. the equilibrium constant of electron transfer between primary (qa) and secondary (qb) quinones was much higher than that in rc of purple bacteria. the qb binding to the protein decreased under alkalinization with apparent pk 8.8. the ... | 1991 | 1915846 |
| isolation and protein chemical characterization of the b806-866 antenna complex of the green thermophilic bacterium chloroflexus aurantiacus. | the b806-866 antenna complex was isolated from cytoplasmic membranes of the green thermophilic bacterium chloroflexus aurantiacus. the membranes were treated with 7 m urea at 50 degrees c, the b806-866 antenna complex was solubilized with a mixture of noni-fjdet p-40 (octylphenoxypolyethoxyethanol (sigma)) and sodium dodecylsulphate (2:1) and isolated by sucrose density gradient centrifugation. this antenna complex was characterized by reversed-phase chromatography (fast polypeptide and polynucl ... | 1991 | 1904920 |
| incorporation of light-harvesting complex i alpha and beta polypeptides into the intracytoplasmic membrane of rhodobacter capsulatus. | the light-harvesting complex i (lhi) of rhodobacter capsulatus is an oligomer of basic subunits each consisting of the two different pigment-binding polypeptides lhi alpha and lhi beta, encoded by the pufa (lhi alpha) and pufb (lhi beta) genes. pulse-labeling experiments showed that in the presence of the lhi alpha polypeptide, the lhi beta polypeptide was inserted earlier into the intracytoplasmic membrane than was the lhi alpha polypeptide. each of the pufa and pufb genes was deleted to test w ... | 1991 | 1885514 |
| temperature and solvent effects on reaction centers from chloroflexus aurantiacus and chromatium tepidum. | temperature and solvent effects on reaction center structures were examined in two thermophilic photosynthetic bacteria, chloroflexus aurantiacus and chromatium tepidum, in order to gain insight into the interactions among the reaction center proteins and pigment systems. thermal stability of the reaction centers was found to be proportional to the optimum growth temperature. circular dichroism (cd) spectra in the 250-300 nm region indicated that thermal denaturation destroyed tertiary structure ... | 1991 | 1778980 |
| temperature dependence of charge recombination from the p+qa- and p+qb- states in photosynthetic reaction centers isolated from the thermophilic bacterium chloroflexus aurantiacus. | the temperature dependence of charge recombination from the p+qa- and from the p+qb- states produced by a flash was studied in reaction centers isolated from the photosynthetic thermophilic bacterium chloroflexus aurantiacus. p designates the primary electron donor; qa and qb the primary and secondary quinone electron acceptors respectively. in qb-depleted reaction centers the rate constant (kap) for p+qa- recombination was temperature independent between 0-50 degrees c (17.6 +/- 0.7 s-1 at ph 8 ... | 1991 | 1761060 |
| 5s rrna sequences of representatives of the genera chlorobium, prosthecochloris, thermomicrobium, cytophaga, flavobacterium, flexibacter and saprospira and a discussion of the evolution of eubacteria in general. | 5s rrna sequences were determined for the green sulphur bacteria chlorobium limicola, chlorobium phaeobacteroides and prosthecochloris aestuarii, for thermomicrobium roseum, which is a relative of the green non-sulphur bacteria, and for cytophaga aquatilis, cytophaga heparina, cytophaga johnsonae, flavobacterium breve, flexibacter sp. and saprospira grandis, organisms allotted to the phylum 'bacteroides-cytophaga-flavobacterium' and relatives as determined by 16s rrna analyses. by using a cluste ... | 1990 | 1693658 |
| a phototrophic gliding filamentous bacterium of hot springs, chloroflexus aurantiacus, gen. and sp. nov. | | 1974 | 4374148 |
| the primary structure of cytochrome c-554 from the green photosynthetic bacterium chloroflexus aurantiacus. | the complete nucleotide sequence of the cytochrome c-554 gene from the green photosynthetic bacterium chloroflexus aurantiacus has been determined. the derived amino acid sequence showed that the cytochrome precursor protein consists of 414 residues and contains 4-cys-x-x-cys-his- heme binding motifs. the only regions of the cytochrome c-554 sequence that were found to be significantly similar to the sequences of cytochromes from other organisms were the heme binding sites. the highest similarit ... | 1991 | 1660302 |
| membrane-bound cytochromes in chloroflexus aurantiacus studied by epr. | the heme components of chlorosome-depleted membranes of the green-gliding bacterium chloroflexus aurantiacus were studied by epr spectroscopy. the four major species, which are present in approximately equimolar quantities, are characterized by the following gz values, redox midpoint potentials and orientations of heme planes with respect to the plane of the membrane: gz = 3.40, em = +280 mv, 30 degrees; gz = 3.33, em = 0 mv, 45 degrees; gz = 3.03, em = +95 mv, 40-50 degrees and gz = 2.95, em = ... | 1991 | 1649048 |
| experimental evidence of oligomeric organization of antenna bacteriochlorophyll c in green bacterium chloroflexus aurantiacus by spectral hole burning. | spectral hole burning has been used to prove experimentally the existence in natural antenna of one of the predicted structural optimizing factors--antenna pigment oligomerization [j. theor. biol. 140 (1989) 167]--ensuring high efficiency of excitation energy transfer from antenna to reaction center. this point has been examined for the chlorosomal antenna of green bacterium chloroflexus aurantiacus by hole burning in fluorescence excitation and emission spectra of intact cells at 1.8 k. the per ... | 1992 | 1644194 |
| light and oxygen regulation of the synthesis of bacteriochlorophylls a and c in chloroflexus aurantiacus. | control of the synthesis of bacteriochlorophylls (bchls) a and c by light and oxygen was studied in chloroflexus aurantiacus grown in batch or chemostat culture with serine as the growth-limiting substrate. for comparison, inhibition by gabaculine of the formation of selected tetrapyrroles was studied. the inhibitory effect of gabaculine decreased in the following order of tetrapyrrole formation: coproporphyrin greater than bchl c greater than bchl a. not only did addition of 5-aminolevulinate ( ... | 1992 | 1629158 |
| 13c-nmr study of autotrophic co2 fixation pathways in the sulfur-reducing archaebacterium thermoproteus neutrophilus and in the phototrophic eubacterium chloroflexus aurantiacus. | the unresolved autotrophic co2 fixation pathways in the sulfur-reducing archaebacterium thermoproteus neutrophilus and in the phototrophic eubacterium chloroflexus aurantiacus have been investigated. autotrophically growing cultures were labelled with [1,4-13c1]succinate, and the 13c pattern in cell constituents was determined by 1h- and 13c-nmr spectroscopy of purified amino acids and other cell constituents. in both organisms succinate contributed to less than 10% of cell carbon, the major par ... | 1992 | 1572376 |
| the functional role of protein in the organization of bacteriochlorophyll c in chlorosomes of chloroflexus aurantiacus. | the preparation of five different fractions containing bacteriochlorophyll (bchl) c and their absorption and circular dichroic properties have been described. the fractions investigated were purified chlorosomes, proteolytically modified chlorosomes, chlorosomes treated with lithium dodecyl sulfate (lds) which were subsequently subjected to size-exclusion chromatography, in vitro bchl c aggregates and, additionally, the so-called gef chlorosomes [prepared according to griebenow and holzwarth (19 ... | 1992 | 1541281 |
| isolation, characterization, and amino acid sequences of auracyanins, blue copper proteins from the green photosynthetic bacterium chloroflexus aurantiacus. | three small blue copper proteins designated auracyanin a, auracyanin b-1, and auracyanin b-2 have been isolated from the thermophilic green gliding photosynthetic bacterium chloroflexus aurantiacus. all three auracyanins are peripheral membrane proteins. auracyanin a was described previously (trost, j. t., mcmanus, j. d., freeman, j. c., ramakrishna, b. l., and blankenship, r. e. (1988) biochemistry 27, 7858-7863) and is not glycosylated. the two b forms are glycoproteins and have almost identic ... | 1992 | 1313011 |
| red shift of absorption maxima in chlorobiineae through enzymic methylation of their antenna bacteriochlorophylls. | the bacteriochlorophyll d producing photosynthetic green sulfur bacteria chlorobium vibrioforme forma thiosulfatophilum strain ncib 8327 and c. vibrioforme strain b1-20 respond to reduced light conditions in culture by performing methylations at the 4- and 5-substituents, for example, converting the 4-et into 4-n-pr, 4-i-bu, and even 4-neopn. during this process, the absorption maximum in living cells of c. vibrioforme strain b1-20 red shifts from 714 to about 728 nm. eventually, the c. vibriofo ... | 1990 | 2350541 |
| a high-yield method for the isolation of hydrophobic proteins and peptides from polyacrylamide gels for protein sequencing. | a methodological approach is described which allows the isolation of hydrophobic and hydrophilic proteins and peptides in high yield. the technique consists of (1) preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis, (2) protein elution from polyacrylamide gels with an organic solvent mixture composed of formic acid/acetonitrile/isopropanol/h2o (50/25/15/10, v/v/v/v), and (3) purification of eluted proteins by size exclusion chromatography on a superose 12 column using this org ... | 1990 | 2382824 |
| the primary structure of the chloroflexus aurantiacus reaction-center polypeptides. | the complete nucleotide sequence of two chloroflexus aurantiacus reaction-center genes has been obtained. the amino acid sequence deduced from the first gene showed 40% similarity to the l subunit of the rhodobacter sphaeroides reaction center. this l subunit was 310 amino acids long and had an approximate molecular mass of 35 kda. the second gene began 17 bases downstream from the first gene. the amino acid sequence deduced from it (307 amino acids; 34950 da) was 42% similar to the m subunit of ... | 1989 | 2651125 |
| [site-specific endonuclease caub31 from chloroflexus aurantiacus b3]. | a sequence-specific endonuclease caub3i has been isolated from cell extracts of chloroflexus aurantiacus and partially purified by chromatography on heparin-sepharose; the yield was 3000 units per 1 g of cells. the final preparation is free of non-specific nucleases. it is shown that endonuclease caub3i recognizes 5' t decreases ccgga 3' sequence in double-stranded dna and cleaves it as shown by an arrow. methylation of adenine in the recognition sequence makes it resistant to caub3i. | 1987 | 2823833 |
| photosynthetic reaction centre of chloroflexus aurantiacus. i. primary structure of l-subunit. | the l-subunit primary structure of the reaction centre from chloroflexus aurantiacus composed of 310 amino acid residues has been determined by parallel analysis of the protein and corresponding dna. significant homology between this protein and l-subunits from reaction centres of purple bacteria is observed. this implies close similarity in the tertiary structure of these proteins. | 1988 | 2834225 |
| oxidation-reduction thermodynamics of the acceptor quinone complex in whole-membrane fragments from chloroflexus aurantiacus. | oxidation-reduction thermodynamic equilibria involving the quinone-acceptor complex have been examined in whole-membrane fragments from chloroflexus aurantiacus. the primary quinone acceptor was titrated by monitoring the amount of cytochrome c554 photooxidized by a flash of light as a function of the redox potential. in contrast to previous data obtained in purified plasma membranes, in which the primary quinone acceptor exhibited a midpoint potential equal to -50 mv at ph 8.2, in whole-membran ... | 1988 | 2850180 |
| phototrophic bacteria (an incoherent group of prokaryotes). a taxonomic versus phylogenetic survey. | in spite of their apparently consistent classical systematic scheme the phototropic bacteria are, as 16s-rrna oligonucleotide cataloguing and sequencing have shown, deeply split into phylogenetic divisions of very little relationships between one another. phototrophy as a mode of energy metabolism occurs in the phylogenetic divisions of a) "gram-positive eubacteria", b) "cyanobacteria/chloroplasts", c) "green sulfur bacteria", d) "chloroflexus and related taxa", and e) "purple bacteria and relat ... | 1987 | 3077326 |
| malate dehydrogenase from the thermophilic green bacterium chloroflexus aurantiacus: purification, molecular weight, amino acid composition, and partial amino acid sequence. | malate dehydrogenase (mdh; ec 1.1.1.37) from the thermophilic green nonsulfur bacterium chloroflexus aurantiacus was purified by a two-step procedure involving affinity chromatography and gel filtration. the enzyme consists of identical subunits which had molecular weights of approximately 35,000. in its active form at 55 degrees c, it formed tetramers. at lower temperatures, inactive dimers and trimers existed. antibodies against the purified enzyme were produced, and immunotitration and enzyme ... | 1988 | 3133356 |
| photosynthetic reaction centre of chloroflexus aurantiacus. primary structure of m-subunit. | the m-subunit primary structure of the reaction centre (rc) from chloroflexus aurantiacus composed of 306 amino acid residues has been determined by parallel analysis of the protein and corresponding dna. the blocked n-terminus as well as replacement of the essential histidine liganding mg of an accessory bacteriochlorophyll in purple bacteria by leucine distinguishes the m-subunit of chloroflexus rc from that of purple bacteria. | 1988 | 3288502 |
| the photochemical reaction center of chloroflexus aurantiacus is composed of two structurally similar polypeptides. | a method has been devised which allowed the isolation of highly purified reaction center from the thermophilic green bacterium, chloroflexus aurantiacus. the procedure consisted of three chromatography steps. the final step was fast protein liquid chromatography on mono q in the presence of nonanoyl-n-methylglucamide (mega-9). the purified reaction center complex was photochemically active and had an a280/a813 of 1.4 or less. under non-denaturing conditions, a pigmented protein band having a mr ... | 1987 | 3308462 |
| structural differences in chlorosomes from chloroflexus aurantiacus grown under different conditions support the bchl c-binding function of the 5.7 kda polypeptide. | structurally different chlorosomes were isolated from the green photosynthetic bacterium chloroflexus aurantiacus grown under different conditions. they were analysed with respect to variable pigment-protein stoichiometries in view of the presumed bchl c-binding function of the 5.7 kda chlorosome polypeptide. under high-light conditions on substrate-limited growth medium the pigment-protein ratio of isolated chlorosomes was several times lower than under low-light conditions on complex medium. p ... | 1994 | 8150092 |
| subunit structure of atp synthase from chloroflexus aurantiacus. | an atp synthase has been isolated from green nonsulfur photosynthetic bacterium chloroflexus aurantiacus, a representative of a lower branch of eubacteria. the enzyme, reconstituted with the bacterial lipids into proteoliposomes, is shown to catalyze [32p]pi-atp exchange (at a rate of 180 nmol [32p]atp/min/mg). the atp synthase is composed of nine polypeptide species (60, 50, 33, 19, 16.5, 15.5, 14.5, 13, and 8 kda as determined by urea-sds-page). the catalytic part of the atp synthase (which is ... | 1993 | 8243672 |
| absence of a characteristic cell wall lipopolysaccharide in the phototrophic bacterium chloroflexus aurantiacus. | two strains of the gliding phototrophic bacterium chloroflexus aurantiacus were investigated for the presence of lipopolysaccharide (lps). with both strains, all fractions of hot phenol-water extracts and the extracted cell residues from whole cells or cell homogenates were found to be free from characteristic lps constituents, such as 3-hydroxy fatty acids, 2-keto-3-deoxyoctonate, heptoses, or o-chain sugars. phenolchloroform-petroleum ether extracts were also free from precipitable lps. a lipi ... | 1988 | 3384807 |
| antenna organization in green photosynthetic bacteria. 1. oligomeric bacteriochlorophyll c as a model for the 740 nm absorbing bacteriochlorophyll c in chloroflexus aurantiacus chlorosomes. | bacteriochlorophyll (bchl) c was extracted from chloroflexus aurantiacus and purified by reverse-phase high-pressure liquid chromatography. this pigment consists of a complex mixture of homologues, the major component of which is 4-ethyl-5-methylbacteriochlorophyll c stearyl ester. unlike previously characterized bchls c, the pigment from c. aurantiacus is a racemic mixture of diastereoisomers with different configurations at the 2a chiral center. diluting a concentrated methylene chloride solut ... | 1987 | 3442679 |
| antenna organization in green photosynthetic bacteria. 2. excitation transfer in detached and membrane-bound chlorosomes from chloroflexus aurantiacus. | the photosynthetic antenna of chloroflexus aurantiacus includes bacteriochlorophyll (bchl) c740 and bchl a792, both of which occur in chlorosomes, and b808-866 (containing bchl a808 and bchl a866), which is membrane-located (subscripts refer to near-infrared absorption maxima in vivo). bchl a792 is thought to mediate excitation transfer from bchl c740 to bchl a808. lifetimes of fluorescence from bchl c740 and bchl a792 were measured in isolated and membrane-bound chlorosomes in order to study en ... | 1987 | 3442680 |
| pathway of proton transfer in bacterial reaction centers: second-site mutation asn-m44-->asp restores electron and proton transfer in reaction centers from the photosynthetically deficient asp-l213-->asn mutant of rhodobacter sphaeroides. | site-directed mutagenesis of the photosynthetic reaction center (rc) from rhodobacter sphaeroides has shown asp-213 of the l subunit (asp-l213) to be important for photosynthetic viability. replacement of asp-l213 with asn resulted in a photosynthetically deficient mutant, due to the 10(4)-fold slower rate for the proton-coupled electron transfer reaction qa-qb- + 2h+-->qaqbh2 (k(2)ab). the detrimental effect of asn-l213 is surprising since rcs from rhodopseudomonas viridis, rhodospirillum rubru ... | 1993 | 8381964 |
| preliminary analysis of lipids and fatty acids of green bacteria and chloroflexus aurantiacus. | the complex lipids and fatty acids of the seven type species of green bacteria and three strains of chloroflexus aurantiacus were analyzed. the green bacteria contained lipids that behaved as cardiolipin and phosphatidylglycerol on thin-layer chromatography. they did not contain phosphatidylethanolamine or phosphatidylserine. similarly, chloroflexus contained lipids that behaved as phosphatidylglycerol and phosphatidylinositol on thin-layer chromatography and did not contain phosphatidylethanola ... | 1974 | 4421249 |
| isolation of two restriction endonucleases from chloroflexus aurantiacus (caui, cauii). | | 1982 | 6286421 |
| the sequence specificity of endonucleases caui and cauii isolated from chloroflexus aurantiacus. | the type ii restriction enzymes caui and cauii, isolated from chloroflexus aurantiacus, recognize and cleave (at the position indicated by an arrow) the sequences g decreases g a/t cc and cc decreases g/c gg, respectively. these conclusions are supported by the results from restriction site mapping, sequence analysis by partial chemical degradation, end-group analysis after lambda exonuclease treatment and computer-assisted comparison of dna sequence data. | 1982 | 6286422 |
| chloroflexus aurantiacus has 30s ribosomal subunits of the eubacterial type. | ribosomal subunits from chloroflexus aurantiacus were isolated and examined by sucrose gradient sedimentation, gel electrophoresis, and electron microscopy. the 30s subunits had all the characteristic structural features of other eubacterial 30s subunits. the data support the proposal that the absence of the archaebacterial bill is a valid phylogenetic marker of the eubacterial lineage. | 1983 | 6348030 |
| primary photochemistry in the facultative green photosynthetic bacterium chloroflexus aurantiacus. | the mechanism of primary photochemistry has been investigated in purified cytoplasmic membranes and isolated reaction centers of chloroflexus aurantiacus. redox titrations on the cytoplasmic membranes indicate that the midpoint redox potential of p870, the primary electron donor bacteriochlorophyll, is +362 mv. an early electron acceptor, presumably menaquinone has em 8.1 = -50 mv, and a tightly bound photooxidizable cytochrome c554 has em 8.1 = +245 mv. the isolated reaction center has a bacter ... | 1983 | 6671994 |
| isolation of pigmentation mutants of the green filamentous photosynthetic bacterium chloroflexus aurantiacus. | mutants deficient in the production of bacteriochlorophyll c (bchl c) and one mutant lacking colored carotenoids were isolated from the filamentous gliding bacterium chloroflexus aurantiacus. mutagenesis was achieved by using uv radiation or n-methyl-n'-nitro-n-nitrosoguanidine. several clones were isolated that were deficient in bchl c synthesis. all reverted. one double mutant deficient both in bchl c synthesis and in the synthesis of colored carotenoids under anaerobic conditions was isolated ... | 1984 | 6735980 |
| heliothrix oregonensis, gen. nov., sp. nov., a phototrophic filamentous gliding bacterium containing bacteriochlorophyll a. | an unusual filamentous, gliding bacterium was found in a few hot springs in oregon where it formed a nearly unispecific top layer of microbial mats. it contained a bacteriochlorophyll a-like pigment and an abundance of carotenoids. there were no chlorosomes or additional chlorophylls. the organism was aerotolerant and appeared to be photoheterotrophic. it was successfully co-cultured with an aerobic chemoheterotroph in a medium containing glucose and casamino acids. although it has many characte ... | 1985 | 2412519 |
| in vitro kinetics of reduction of cytochrome c554 isolated from the reaction center of the green phototrophic bacterium, chloroflexus aurantiacus. | the photochemical reaction center in the green bacterium chloroflexus aurantiacus is similar to that found in purple phototrophic bacteria and interacts with a multiheme membrane-bound cytochrome. we have examined the kinetics of reduction of the pure solubilized reaction center cytochrome by laser flash photolysis of solutions containing lumiflavin or fmn. reduction by lumiflavin semiquinone followed single exponential kinetics and the observed rate constant (kobs) was linearly dependent on pro ... | 1989 | 2544143 |
| organic nitrogen metabolism of phototrophic bacteria. | recent reviews dealing with phototrophic bacteria are concerned with bioenergetics, nitrogen fixation and hydrogen metabolism, synthesis of the photosynthetic apparatus and phylogeny/taxonomy. the organic n-metabolism of these phylogenetically diverse bacteria has last been reviewed in 1978. however, amino acid utilization and biosynthesis, ammonia assimilation, purine and pyrimidine metabolism and biosynthesis of delta-aminolevulinic acid as precursor of bacteriochlorophylls and hemes are topic ... | 1989 | 2569291 |
| the primary structure of two chlorosome proteins from chloroflexus aurantiacus. | the complete nucleotide sequence of two chlorosome proteins with apparent molecular weights of m(r) 18,000 and m(r) 11,000 from chloroflexus aurantiacus have been determined. the two polypeptides were 145 and 97 amino acids long and possessed true molecular masses of 15,545 and 10,820 da, respectively. protein chemical sequencing was done in parallel to confirm the primary structure deduced from nucleotide sequencing. by northern blot analysis of rna isolated from phototrophically grown cells a ... | 1994 | 7511541 |
| cloning and sequencing of the genes encoding the light-harvesting b806-866 polypeptides and initial studies on the transcriptional organization of puf2b, puf2a and puf2c in chloroflexus aurantiacus. | the genes encoding the alpha- and beta-polypeptide subunits of the b806-866 membrane-bound light-harvesting complex of chloroflexus aurantiacus have been cloned and the nucleotide sequences determined. the gene puf2a, which encodes the b806-866 alpha-polypeptide, began 28 bases downstream of the stop codon of puf2b, which encodes the b806-866 beta gene. the gene-encoding cytochrome c-554, puf2c, was found about 250 bp downstream of puf2a. puf2a encoded a 13 amino acid extension at the c-terminus ... | 1995 | 7535995 |
| chloroflexus aggregans sp. nov., a filamentous phototrophic bacterium which forms dense cell aggregates by active gliding movement. | two strains of thermophilic photosynthetic bacteria, designated md-66t (t = type strain) and yi-9, were isolated from bacterial mats in two separate hot springs in japan. these new isolates were phenotypically similar to chloroflexus aurantiacus in some respects. they were thermophilic filamentous photosynthetic bacteria that grew well at 55 degrees c either anaerobically as photoheterotrophs or aerobically as chemoheterotrophs. they exhibited gliding motility, produced bacteriochlorophylls a an ... | 1995 | 7547286 |
| polyclonal antibodies to chlorosome proteins as probes for green sulfur bacteria. | we found that polyclonal antibodies raised against chlorosome polypeptides from green sulfur bacteria reacted to chlorobium tepidum, chlorobium limicola, and chlorobium phaeobacteroides but not to chloroflexus aurantiacus. these antibodies successfully labeled only green sulfur species in marine microbial mat samples. our results suggest that these antibodies may be useful as immunohistochemical probes. | 1995 | 7574615 |
| near-infrared resonance raman spectra of chloroflexus aurantiacus photosynthetic reaction centers. | resonance raman spectra of the photosynthetic reaction center isolated from the green bacterium chloroflexus aurantiacus have been obtained with excitation in the near-infrared absorption bands of the special pair (p) and the accessory bacteriochlorophyll (b) using shifted-excitation raman difference spectroscopy (serds). these spectra are compared with the previously reported raman spectra of p and b in reaction centers from the purple bacterium rhodobacter sphaeroides. the spectra of p and b f ... | 1995 | 7711050 |
| purification and characterization of a thermostable neutral metalloprotease i from chloroflexus aurantiacus j-10-fl. | chloroflexus aurantiacus j-10-fl was found to contain two types (protease i and protease ii) of thermostable proteases which were separated by butyl-toyopearl 650 m chromatography. protease i was purified to electrophoretic homogeneity from the culture broth of c. aurantiacus j-10-fl. the molecular mass of protease i was estimated to be approximately 66 kda by sds-page, and the value of approximately 66 kda was also obtained by the hedrick-smith method, indicating that protease i was a monomer. ... | 1993 | 7764368 |
| presence and significance of minor antenna components in the energy transfer sequence of the green photosynthetic bacterium chloroflexus aurantiacus. | antenna components in the energy transfer processes of a green photosynthetic bacterium chloroflexus aurantiacus were spectrally investigated by time-resolved fluorescence spectroscopy at -196 degrees c on intact cells. besides major antenna components so far reported, three minor components were resolved; those were bchl c located at 785 nm, the baseplate bchl a at 819 nm and bchl a in the b808-866 complex at 910 nm. the last component was assigned to a longer wavelength antenna closely associa ... | 1994 | 8131839 |
| retrobiosynthetic analysis of carbon fixation in the phototrophic eubacterium chloroflexus aurantiacus. | the phototrophic bacterium chloroflexus aurantiacus does not use any of the known autotrophic co2 fixation pathways. there is evidence for a new cyclic autotrophic pathway in which acetyl-coa is converted to 3-hydroxypropionate and further to succinate and malate. this hypothesis was tested by feeding growing cultures during several generations with 3-hydroxy[1-13c]propionate, [1-13c]acetate, or [2-13c]acetate, in addition to unlabeled co2. the relative 13c content of individual carbon atoms in ... | 1993 | 8354268 |
| enzymes of a novel autotrophic co2 fixation pathway in the phototrophic bacterium chloroflexus aurantiacus, the 3-hydroxypropionate cycle. | the phototrophic bacterium chloroflexus aurantiacus can grow autotrophically but seems not to assimilate co2 via any of the known autotrophic pathways. holo [holo, h. (1989) arch. microbiol. 151, 252-256] proposed a new pathway in which 3-hydroxypropionate is formed from acetyl-coa. previous studies excluded the operation of known co2 fixation pathways and provided indirect evidence for the suggested pathway based on 13c-labelling experiments. here all enzyme activities of the postulated cyclic ... | 1993 | 8354269 |
| picosecond energy transfer and trapping kinetics in living cells of the green bacterium chloroflexus aurantiacus. | the excitation energy transfer and trapping processes in intact cells of chloroflexus aurantiacus were studied by picosecond time-resolved fluorescence spectroscopy. the fluorescence decay kinetics is investigated over the near infrared emission range between 730 nm and 920 nm using various excitation wavelengths and excitation intensities. the data were analyzed by global decay analysis and are presented as decay-associated spectra (das). the specific dependence of the decay kinetics on the exc ... | 1993 | 8369334 |
| structure and protein binding interactions of the primary donor of the chloroflexus aurantiacus reaction center. | soret resonance, qx resonance, and qy near-infrared fourier transform (ft) (pre)resonance raman spectroscopies were used to determine pigment-protein interactions of specific bacteriochlorin molecules in the reaction center from chloroflexus aurantiacus. ft raman spectroscopy, using 1064 nm excitation, was used to selectively obtain preresonance and resonance vibrational raman spectra of the primary donor (p) of reaction centers (rcs) from chloroflexus aurantiacus in the po and p.+ states, respe ... | 1996 | 8634255 |
| oxygen regulation of development of the photosynthetic membrane system in chloroflexus aurantiacus. | oxygen levels which control induction of the assembly of the pigment-protein photosynthetic polypeptides in dark-grown chloroflexus aurantiacus were determined. the induction signal by low-oxygen tension is not directly related to the respiratory competence of these photosynthetic cells. cytochrome c554, the primary electron donor to p865+ of the reaction center, is not present in dark-grown respiratory cells but is induced in parallel with bacteriochlorophylls a and c and at similar oxygen part ... | 1986 | 3733673 |
| sequence of the bchg gene from chloroflexus aurantiacus: relationship between chlorophyll synthase and other polyprenyltransferases. | the sequence of the chloroflexus aurantiacus open reading frame thought to be the c. aurantiacus homolog of the rhodobacter capsulatus bchg gene is reported. the bchg gene product catalyzes esterification of bacteriochlorophyllide a by geranylgeraniol-ppi during bacteriochlorophyll a biosynthesis. homologs from arabidopsis thaliana, synechocystis sp. strain pcc6803, and c. aurantiacus were identified in database searches. profile analysis identified three related polyprenyltransferase enzymes wh ... | 1996 | 8655525 |
| excitation delocalization in the bacteriochlorophyll c antenna of the green bacterium chloroflexus aurantiacus as revealed by ultrafast pump-probe spectroscopy. | room temperature absorption difference spectra were measured on the femtosecond through picosecond time scales for chlorosomes isolated from the green bacterium chloroflexus aurantiacus. anomalously high values of photoinduced absorption changes were revealed in the bchl c qy transition band. photoinduced absorption changes at the bleaching peak in the bchl c band were found to be 7-8 times greater than those at the bleaching peak in the bchl a band of the chlorosome. this appears to be the firs ... | 1998 | 9688564 |
| malate dehydrogenase from the green gliding bacterium chloroflexus aurantiacus is phylogenetically related to lactic dehydrogenases. | the gene encoding malate dehydrogenase (mdh) from chloroflexus aurantiacus was cloned, sequenced, and analyzed. the mdh gene corresponded to a polypeptide of 309 amino acids with a molecular mass of 32,717 da. the primary structure and the coenzyme-binding domain showed a high degree of similarity to lactate dehydrogenase (ldh), whereas the conserved amino acids that participate in substrate binding were those typical of mdhs. using pcr techniques, the mdh gene was cloned in the expression vecto ... | 1996 | 8661927 |
| phylogenetic heterogeneity within the genus herpetosiphon: transfer of the marine species herpetosiphon cohaerens, herpetosiphon nigricans and herpetosiphon persicus to the genus lewinella gen. nov. in the flexibacter-bacteroides-cytophaga phylum. | analysis of the 16s rdna sequences of species currently assigned to the genus herpetosiphon revealed intrageneric phylogenetic heterogeneity. the thermotolerant freshwater species herpetosiphon geysericola is most closely related to the type species herpetosiphon aurantiacus in the chloroflexus subdivision of the green non-sulfur bacteria. the marine species herpetosiphon cohaerens, herpetosiphon nigricans and herpetosiphon persicus, on the other hand, were found to form a cluster with sheathed ... | 1998 | 9734027 |
| anoxygenic phototrophy across the phylogenetic spectrum: current understanding and future perspectives | the phylogenetic heterogeneity of anoxygenic phototrophic bacteria has been revealed by 16s rrna sequence analysis, the results of which have led to extensive taxonomic rearrangements within previously defined taxa of phototrophs and stimulated interest in this group of organisms. anoxygenic photosynthetic bacteria can be found within 4 of the 12 phylogenetic lineages, and in some cases are highly related to non-photosynthetic members of these groups. the largest number of phototrophs are found ... | 1996 | 8824144 |
| denaturing gradient gel electrophoresis used to monitor the enrichment culture of aerobic chemoorganotrophic bacteria from a hot spring cyanobacterial mat. | previous studies investigating microbial diversity in the octopus spring cyanobacterial mat community (yellowstone national park) have shown a discrepancy between bacterial populations observed by molecular retrieval and cultivation techniques. to investigate how selective enrichment culture techniques affect species composition, we used denaturing gradient gel electrophoresis (dgge) separation of pcr-amplified 16s rrna gene fragments to monitor the populations contained within enrichment cultur ... | 1996 | 8899977 |
| crystallization and x-ray analysis of the reaction center from the thermophilic green bacterium chloroflexus aurantiacus. | the photochemical reaction center of chloroflexus (cf.) aurantiacus, a membrane bound pigment-protein complex, has been crystallized in the presence of monodisperse polyoxyethylene detergents. the crystals possessed a pronounced polymorphism. three different crystal forms belonging to triclinic, monoclinic and orthorhombic space groups have been characterized by x-ray analysis. the triclinic crystal form, with unit cell dimensions of a = 88 a, b = 115 a and c = 151 a, diffracts up to 3.2 a in tw ... | 1996 | 8914980 |
| temperature dependence of growth and membrane-bound activities of chloroflexus aurantiacus energy metabolism. | the temperature dependence of various activities related to the energy metabolism of isolated membranes and whole cells of the thermophilic bacterium chloroflexus aurantiacus was determined after phototrophic growth at either 40, 50, or 60 degrees c. the data obtained were expressed by use of arrhenius plots. maximum activities were determined at about 65 degrees c for succinate 2,4-dichlorophenol-indophenol reductase as well as nadh oxidase and at about 70 degrees c for mg-atpase and for light- ... | 1983 | 6863222 |
| isolation and characterization of cytoplasmic membranes and chlorosomes from the green bacterium chloroflexus aurantiacus. | a method was developed which allows the isolation and purification of cytoplasmic membranes and chlorosomes from cells of chloroflexus aurantiacus grown under different light conditions. the dipolar ionic detergent deriphat (0.08%) and a sodium iodide gradient centrifugation were used in isolating cytoplasmic membranes. chlorosomes were prepared with 0.16% of the dipolar ionic detergent miranol and purified by a sucrose gradient centrifugation. cytoplasmic membrane fractions prepared from either ... | 1982 | 7068536 |
| isolation and development of chlorosomes in the green bacterium chloroflexus aurantiacus. | freeze-fracture electron microscopy was used to study further the changes in chlorosome structure during the development of the photosynthetic apparatus in chloroflexus aurantiacus j-10-fl. during development, in response to decreased light intensity or lower oxygen tension, the number of chlorosomes per cell increased. the same conditions also led to a general thickening of chlorosomes but did not affect their length or width. the thickening of the chlorosomes paralleled increases in the bacter ... | 1981 | 7275928 |
| semiaerobic induction of bacteriochlorophyll synthesis in the green bacterium chloroflexus aurantiacus. | comparison of chloroflexus aurantiacus j-10-fl cells by freeze-fracture electron microscopy showed that cell shape and dimensions did not depend on oxygen tension or light intensity during growth. the major morphological difference between cells cultured anaerobically in the light and aerobically in the dark was the absence of chlorosomes in aerobically grown cells. c. aurantiacus cells cultured aerobically in the dark began bacteriochlorophyll synthesis immediately when shifted to either photot ... | 1981 | 7275929 |
| structure and composition of freshwater microbial mats from a sulfur spring ("font pudosa", ne spain). | different types of microbial mats developing on the wall on a non-thermal sulfur freshwater spring have been studied. both, light and electron microscopy as well as hplc analysis of photosynthetic pigments revealed their structure and composition. prokaryotic chlorophylls and carotenoids helped in the taxonomical assignment of the main photosynthetic groups. "inverted position" mats (mat-i) were dominated by chromatiaceae; they were located closed to the water outlets (0.3 mm sulfide). "normal p ... | 1997 | 9106181 |
| mixed lipid-protein films of bacterial photosynthetic reaction centres. ii. mixed multilayers on solid supports. | mixed lipid-protein multilayers composed of the reaction centre (rc) proteins from the chloroflexus aurantiacus and rhodobacter sphaeroides (wild type) photosynthetic bacteria and synthetic lipids were investigated. the optimal conditions for forming thin films on solid plates (approximately 100% transfer) were 30 mn/m surface pressure and transfer of the interfacial monolayers from the buffer/air interface onto the plates by the langmuir-schaefer method. the films transferred onto quartz and op ... | 1997 | 9225257 |
| lipid biomarkers for bacterial ecosystems: studies of cultured organisms, hydrothermal environments and ancient sediments. | this paper forms part of our long-term goal of using molecular structure and carbon isotopic signals preserved as hydrocarbons in ancient sediments to improve understanding of the early evolution of earth's surface environment. we are particularly concerned with biomarkers which are informative about aerobiosis. here, we combine bacterial biochemistry with the organic geochemistry of contemporary and ancient hydrothermal ecosystems to construct models for the nature, behaviour and preservation p ... | 1996 | 9243016 |
| structure of the puf operon of the obligately aerobic, bacteriochlorophyll alpha-containing bacterium roseobacter denitrificans och114 and its expression in a rhodobacter capsulatus puf puc deletion mutant. | roseobacter denitrificans (erythrobacter species strain och114) synthesizes bacteriochlorophyll a (bchl) and the photosynthetic apparatus only in the presence of oxygen and is unable to carry out primary photosynthetic reactions and to grow photosynthetically under anoxic conditions. the puf operon of r. denitrificans has the same five genes in the same order as in many photosynthetic bacteria, i.e., pufbalmc. pufc, the tetraheme subunit of the reaction center (rc), consists of 352 amino acids ( ... | 1997 | 9286973 |
| new carotenoids from the thermophilic green sulfur bacterium chlorobium tepidum: 1',2'-dihydro-gamma-carotene, 1',2'-dihydrochlorobactene, and oh-chlorobactene glucoside ester, and the carotenoid composition of different strains. | the complete carotenoid composition of the thermophilic green sulfur bacterium chlorobium tepidum strain tno was determined by spectroscopic methods. major carotenoids were four kinds of carotenes: gamma-carotene, chlorobactene, and their 1',2'-dihydro derivatives (1',2'-dihydro-gamma-carotene and 1',2'-dihydrochlorobactene). in lesser amounts, hydroxyl gamma-carotene, hydroxyl chlorobactene, and their glucoside fatty acid esters were found. the only esterified fatty acid present was laurate, an ... | 1997 | 9297463 |
| characterization of novel long-chain 1,2-diols in thermus species and demonstration that thermus strains contain both glycerol-linked and diol-linked glycolipids. | in this study, we purified and characterized tetra- and triglycosyl glycolipids (gl-1 and gl-2, respectively) from two different colonial forms of thermus scotoductus x-1, from t. filiformis tok4 a2, and from t. oshimai sps-11. acid hydrolysis of the purified glycolipids liberated, in addition to the expected long-chain fatty acids, two components which were identified by gas chromatography-mass spectrometry as 16-methylheptadecane-1,2-diol and 15-methylheptadecane-1,2-diol. fast atom bombardmen ... | 1997 | 9324266 |
| b12-dependent ribonucleotide reductases from deeply rooted eubacteria are structurally related to the aerobic enzyme from escherichia coli. | the ribonucleotide reductases from three ancient eubacteria, the hyperthermophilic thermotoga maritima (tm), the radioresistant deinococcus radiodurans (dr), and the thermophilic photosynthetic chloroflexus aurantiacus, were found to be coenzyme-b12 (class ii) enzymes, similar to the earlier described reductases from the archaebacteria thermoplasma acidophila and pyrococcus furiosus. reduction of cdp by the purified tm and dr enzymes requires adenosylcobalamin and dtt. datp is a positive alloste ... | 1997 | 9391052 |
| cloning, sequence analysis and expression in e. coli of the dna polymerase i gene from chloroflexus aurantiacus, a green nonsulfur eubacterium. | we have cloned and sequenced the pola gene from chloroflexus aurantiacus, a green nonsulfur eubacterium, and expressed the recombinant protein in escherichia coli. one open reading frame encodes a protein with 942 amino acids showing 38% identity with dna polymerase i from e. coli. sequence alignments with other members of dna polymerase family a and analysis of the separate domains show that the central 3'-5' exonuclease domain is 30% identical to the corresponding e. coli domain and that three ... | 1998 | 9526698 |
| 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 |
| the phylogenetic relationships of chlorobium tepidum and chloroflexus aurantiacus based upon their reca sequences. | using reca as the phylogenetic marker, the relationships of the green sulfur bacterium chlorobium tepidum and the green non-sulfur bacterium chloroflexus aurantiacus to other eubacteria were investigated. the reca genes of the two organisms were cloned, and the resulting protein sequences aligned with 86 other eubacterial reca sequences. cb. tepidum was placed as the nearest relative to the cytophaga/flexibacter/bacteriodes group, a relationship supported by results obtained with several phyloge ... | 1998 | 9595663 |
| biosynthesis of the diterpene verrucosan-2beta-ol in the phototrophic eubacterium chloroflexus aurantiacus. a retrobiosynthetic nmr study. | the biosynthesis of verrucosan-2beta-ol in the green phototrophic eubacterium chloroflexus aurantiacus was investigated by in vivo incorporation of singly or doubly 13c-labeled acetate. the 13c labeling of the isolated diterpene was analyzed by one- and two-dimensional nmr spectroscopy. the 13c-labeling patterns of verrucosan-2beta-ol were compared with the labeling patterns of intermediary metabolites (acetyl-coa, pyruvate, and glyceraldehyde 3-phosphate) which were deduced from amino acids and ... | 1998 | 9660767 |
| pigment organization and exciton dynamics in the b808-866 antenna of the green bacterium chloroflexus aurantiacus. | the model for the b808-866 antenna of the green photosynthetic bacterium chloroflexus aurantiacus based on femtosecond pump-probe studies is proposed. the three-dimensional structure of the b808-866 antenna is assumed to be similar to the structure of the b800-850 antenna of purple bacteria, i.e. it has the form of two concentric rings of n strongly coupled bchl866 pigments and of n/2 weakly coupled bchl808 monomers. the qy transition dipoles of bchl808 and bchl866 molecules form the angles 43 d ... | 1998 | 9678257 |
| characterization of the group 1 and group 2 sigma factors of the green sulfur bacterium chlorobium tepidum and the green non-sulfur bacterium chloroflexus aurantiacus. | the group 1 and group 2 sigma70-type sigma factors of the green sulfur bacterium chlorobium tepidum and of the green nonsulfur bacterium chloroflexus aurantiacus were cloned and characterized. cb. tepidum was found to contain one sigma70-type sigma factor; the expression of the gene was analyzed by northern blot hybridization and primer-extension mapping. cf. aurantiacus has genes encoding four sigma factors of groups 1 and 2. the expression of these genes was examined in cells grown aerobically ... | 1998 | 9732443 |
| changes in quinone profiles of hot spring microbial mats with a thermal gradient | the respiratory and photosynthetic quinones of microbial mats which occurred in japanese sulfide-containing neutral-ph hot springs at different temperatures were analyzed by spectrochromatography and mass spectrometry. all of the microbial mats that developed at high temperatures (temperatures above 68 degreesc) were so-called sulfur-turf bacterial mats and produced methionaquinones (mtks) as the major quinones. a 78 degreesc hot spring sediment had a similar quinone profile. chloroflexus-mixed ... | 1999 | 9872780 |
| presence of acetyl coenzyme a (coa) carboxylase and propionyl-coa carboxylase in autotrophic crenarchaeota and indication for operation of a 3-hydroxypropionate cycle in autotrophic carbon fixation. | the pathway of autotrophic co2 fixation was studied in the phototrophic bacterium chloroflexus aurantiacus and in the aerobic thermoacidophilic archaeon metallosphaera sedula. in both organisms, none of the key enzymes of the reductive pentose phosphate cycle, the reductive citric acid cycle, and the reductive acetyl coenzyme a (acetyl-coa) pathway were detectable. however, cells contained the biotin-dependent acetyl-coa carboxylase and propionyl-coa carboxylase as well as phosphoenolpyruvate ca ... | 1999 | 9973333 |
| taxon-specific content of oligonucleotide triplets in 16s rrnas of anoxygenic phototrophic and nitrifying bacteria. | theoretical evaluation of the content of oligonucleotide triplets aaa, ccc, and uau in 16s rrnas of anoxygenic phototrophic bacteria (genera chlorobium; chloroflexus; chromatium: rhodopseudomonas) and nitrifying bacteria (genera nitrosococcus, nitrosomonas, nitrosolobus, nitrosovibrio, nitrospira, nitrospina, nitrobacter) showed that the number of the aaa, ccc or uau triplets in 16s rrnas specifically corresponds to the genus and species of bacteria. the ratio of aaa and ccc triplet numbers in t ... | 1999 | 10049622 |
| auracyanin a from the thermophilic green gliding photosynthetic bacterium chloroflexus aurantiacus represents an unusual class of small blue copper proteins. | the amino acid sequence of the small copper protein auracyanin a isolated from the thermophilic photosynthetic green bacterium chloroflexus aurantiacus has been determined to be a polypeptide of 139 residues. his58, cys123, his128, and met132 are spaced in a way to be expected if they are the evolutionary conserved metal ligands as in the known small copper proteins plastocyanin and azurin. secondary structure prediction also indicates that auracyanin has a general beta-barrel structure similar ... | 1999 | 10338005 |
| antenna size dependent exciton dynamics in the chlorosomal antenna of the green bacterium chloroflexus aurantiacus. | using picosecond fluorescence spectroscopy, we demonstrated antenna size dependent exciton dynamics in chlorosomal antenna, measured for intact cells of different cultures of the green bacterium chloroflexus aurantiacus with different chlorosomal antenna size determined by electron microscopic examination of ultrathin sections of the cells. the measured bacteriochlorophyll (bchl) c excitation lifetimes show a quasilinear dependence on chlorosome size as predicted in our model for cylindrical exc ... | 1996 | 8925903 |
| evolutionary relationships among photosynthetic prokaryotes (heliobacterium chlorum, chloroflexus aurantiacus, cyanobacteria, chlorobium tepidum and proteobacteria): implications regarding the origin of photosynthesis. | the presence of shared conserved insertions or deletions in proteins (referred to as signature sequences) provides a powerful means to deduce the evolutionary relationships among prokaryotic organisms. this approach was used in the present work to deduce the branching orders of various eubacterial taxa consisting of photosynthetic organisms. for this purpose, portions of the hsp60 and hsp70 genes, covering known signature sequence regions, were pcr-amplified and sequenced from heliobacterium chl ... | 1999 | 10361294 |
| redox effects on the excited-state lifetime in chlorosomes and bacteriochlorophyll c oligomers. | oligomers of [e,e] bchl cf (8, 12-diethyl bacteriochlorophyll c esterified with farnesol (f)) and [pr,e] bchl cf (analogously, m methyl, pr propyl) in hexane and aqueous detergent or lipid micelles were studied by means of steady-state absorption, time-resolved fluorescence, and electron spin resonance spectroscopy. the maximum absorption wavelength, excited-state dynamics, and electron spin resonance (epr) linewidths are similar to those of native and reconstituted chlorosomes of chlorobium tep ... | 1997 | 8994616 |
| evidence that eukaryotic triosephosphate isomerase is of alpha-proteobacterial origin. | we have cloned and sequenced genes for triosephosphate isomerase (tpi) from the gamma-proteobacterium francisella tularensis, the green non-sulfur bacterium chloroflexus aurantiacus, and the alpha-proteobacterium rhizobium etli and used these in phylogenetic analysis with tpi sequences from other members of the bacteria, archaea, and eukarya. these analyses show that eukaryotic tpi genes are most closely related to the homologue from the alpha-proteobacterium and most distantly related to archae ... | 1997 | 9037042 |
| biodiversity within hot spring microbial mat communities: molecular monitoring of enrichment cultures. | we have begun to examine the basis for incongruence between hot spring microbial mat populations detected by cultivation or by 16s rrna methods. we used denaturing gradient gel electrophoresis (dgge) to monitor enrichments and isolates plated therefrom. at near extincting inoculum dilutions we observed chloroflexus-like and cyanobacterial populations whose 16s rrna sequences have been detected in the 'new pit' spring chloroflexus mat and the octopus spring cyanobacterial mat. cyanobacterial popu ... | 1997 | 9049026 |