| the cu(ii)-repressible plastidic cytochrome c. cloning and sequence of a complementary dna for the pre-apoprotein. | we have cloned a complementary dna for pre-apocytochrome c-552 from chlamydomonas reinhardtii. the deduced sequence of the mature protein shows high homology to those of cytochromes c-553 from cyanobacteria. its homology to mitochondrial cytochrome c or bacterial photosynthetic cytochrome c2 is lower and appears to be concentrated in sequences around amino acids involved in the interaction with heme. with respect to primary sequence, the "transit sequence" for cytochrome c-552 appears to show no ... | 1987 | 3036842 |
| reduction and destruction rates of nitroxide spin probes. | a series of nitroxides was tested for rates of one-electron reduction in a chemical, a photochemical, and two biological systems by esr assays. in all cases, piperidine and hydropyridine nitroxides were reduced consistently more rapidly than pyrroline and pyrrolidine nitroxides. substituents on the nitroxides also affected reduction rates, although not as greatly as ring structure. one of the reduction systems, consisting of the photosensitizer fmn and the photoreductant edta, was used to study ... | 1987 | 3038021 |
| 23na and 31p nmr studies of the effects of salt stress on the freshwater cyanobacterium synechococcus 6311. | we have used 23na and 31p nuclear magnetic resonance (nmr) spectroscopy to elucidate some of the bioenergetic changes that occur in the freshwater cyanobacterium synechococcus 6311 after a transition from growth medium (na concentration 0.01 m) to medium containing 0.5 m nacl. 23na nmr analysis showed na rapidly penetrates the cells under dark aerobic conditions; cells grown for several days in high salt medium, however, reestablish a low internal sodium content, comparable to control cells. for ... | 1987 | 3038026 |
| modulation of nitrate uptake in anacystis nidulans by the balance between ammonium assimilation and co2 fixation. | gradual inhibition of ammonium assimilation in anacystis nidulans cells by increasing concentrations of 5-hydroxylysine resulted in a progressive enhancement of nitrate uptake. for 5-hydroxylysine-treated cells, the magnitude of the inhibition of nitrate uptake promoted by added ammonium was dependent on the ammonium assimilation capacity. in cells with a moderate ammonium assimilation activity, acceleration of co2 fixation induced by bicarbonate addition antagonized the negative effect of ammon ... | 1987 | 3039915 |
| the organization and sequence of the genes for atp synthase subunits in the cyanobacterium synechococcus 6301. support for an endosymbiotic origin of chloroplasts. | the nucleotide sequence has been determined of two regions of dna cloned from the cyanobacterium synechococcus 6301. the larger, 8890 base-pairs in length, contains a cluster of seven genes for subunits of atp synthase. the order of the genes is a:c:b':b:delta:alpha:gamma, b' being a duplicated and diverged form of b. as in the escherichia coli unc operon, the a gene is preceded by a gene for a small hydrophobic and basic protein. the hydrophobic profile of the potential gene product suggests th ... | 1987 | 3041005 |
| 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 |
| membrane electrogenesis and sodium transport in filamentous nitrogen-fixing cyanobacteria. | transport of na+ and its relationship with membrane potential (delta psi m) was examined in anabaena l-31 (a fresh water cyanobacterium) and anabaena torulosa (a brackish water cyanobacterium) which require na+ for diazotrophic growth. the data on the effect of n,n'-dicyclohexylcarbodiimide indicated that delta psi m was generated by electrogenic proton extrusion predominantly mediated by atpase(s). in addition, operation of a plasmalemmabound, non-atp-requiring, h+-pumping terminal oxidase was ... | 1986 | 3080316 |
| photoheterotrophic growth of agmenellum quadruplicatum pr-6. | the unicellular cyanobacterium agmenellum quadruplicatum pr-6 grows in the presence of light on agar containing 10 microm 3-(3,4 dichlorophenyl)-1,1-dimethylurea and 1 to 30 mm glycerol. a derivative strain, pr-6g2, was tolerant of 100 mm glycerol. photoheterotrophic growth conditions had little effect on transformation competence but did decrease the viability of single cells plated onto agar, particularly cells of the parent strain. | 1986 | 3080411 |
| isolation of an intrinsic antenna chlorophyll a-protein from the photosystem i reaction center complex of the thermophilic cyanobacterium synechococcus sp. | a chlorophyll-protein was isolated from a synechococcus p700-chlorophyll a-protein complex free from small subunits (cp1-e) by sodium dodecyl sulfate (sds)-polyacrylamide gel electrophoresis after treatment with 2% 2-mercaptoethanol and 2% sds. in contrast to cp1-e which, when electrophoresed under denaturating conditions, showed two polypeptide bands of 62 and 60 kda, the chlorophyll-protein contained only the 60-kda polypeptide and hence is called cp60. the yield of cp60 was maximal with 1-2% ... | 1986 | 3080948 |
| transport and accumulation of nickel ions in the cyanobacterium anabaena cylindrica. | the uptake of nickel ions by the cyanobacterium anabaena cylindrica was studied. nickel transport was dependent on the membrane potential of the cells and the rate of uptake was decreased in the dark or by the addition of inhibitors, including uncouplers and electron transport inhibitors, which decreased or abolished the membrane potential of cells. the transport process obeyed hyperbolic kinetics, with a high affinity (apparent km = 17 +/- 11 (sem) nm) and low turnover number (maximum velocity ... | 1986 | 3080951 |
| evidence for direct repression of nitrogenase by ammonia in the cyanobacterium anabaena cylindrica. | the nitrogenase activity of the cyanobacterium anabaena cylindrica was repressed upon addition of ammonium salts after preincubation in the presence of a concentration of l-methionine-dl-sulfoximine sufficient to totally inhibit glutamine synthetase. repression was also observed when urea was added to cells in the presence of the glutamine synthetase inhibitor. measurements of ammonia concentrations were made in each case and provided evidence that ammonia itself is a primary regulator of nitrog ... | 1986 | 3080996 |
| stable transformation of the cyanobacterium synechocystis sp. pcc 6803 induced by uv irradiation. | irradiation of the photoheterotrophic cyanobacterium synechocystis sp. pcc 6803 with low levels of uv light allows for stable, integrative transformation of these cells by heterologous dna. in this system, transformation does not rely on an autonomously replicating plasmid and is independent of homologous recombination. cells treated with uv light in the absence of dna and cells given dna but not exposed to uv do not yield antibiotic-resistant colonies in platings of up to 2 x 10(8) cells. optim ... | 1986 | 3081493 |
| phenylalanyl-trna synthetase from chloroplasts of a higher plant (phaseolus vulgaris). purification and comparison of its structural, functional, and immunological properties with those of the enzymes from the corresponding cytoplasm, the cyanobacterium anacystis nidulans, and the photosynthetic green sulfur bacterium chlorobium limicola. | chloroplastic phenylalanyl-trna synthetase from bean leaves is purified under optimal protective conditions over 4,900-fold. its apparent molecular weight is 78,000, as determined by gel filtration, with a dimeric subunit structure of alpha beta (alpha = 33,000 and beta = 42,000), as determined by sodium dodecyl sulfate gel electrophoresis. this indicates a drastic size reduction of 40% for each subunit compared to the corresponding cytoplasmic enzyme and a unique quaternary structure. heterolog ... | 1986 | 3081498 |
| analysis of fluorescence kinetics and energy transfer in isolated alpha subunits of phycoerythrin from nostoc sp. | | 1986 | 3081920 |
| organization of the genes for protein synthesis elongation factors tu and g in the cyanobacterium anacystis nidulans. | the genes for protein synthesis elongation factors tu and g were cloned from the cyanobacterium anacystis nidulans. the locations of these genes were mapped within the cloned dna fragment by hybridization with escherichia coli probes. the organization of the cloned fragment and the dna flanking it in the a. nidulans chromosome was also determined. the elongation factor tu and g genes are adjacent to one another and in the same 5'-to-3' orientation. in contrast to other gram-negative bacteria, a. ... | 1986 | 3082860 |
| effect of tryptophan on 2,4-dichlorophenoxyacetic acid toxicity in the nitrogen-fixing-cyanobacterium nostoc linckia. | the combined effect of a hormone weed killer 2,4-dichlorophenoxyacetic acid (2,4-d) and an amino acid (tryptophan) has been studied on growth and heterocyst differentiation in the cyanobacterium nostoc linckia. 2.4-d at 100 micrograms/ml stimulated growth and heterocyst frequency in combined nitrogen-free medium while its higher concentrations inhibited both. tryptophan under similar conditions promoted much growth yield with 3-4 fold enhanced heterocyst frequency than the control. such heterocy ... | 1986 | 3083089 |
| method for determining the temporal response of microbial phosphate transport affinity. | nutrient transport affinities of nutrient-starved microbial populations were measured as initial slopes of plots of limiting-nutrient transport rates versus extracellular limiting-nutrient concentrations. a method was devised for the determination of soluble reactive phosphate (pi) affinity in pi-limited continuous culture (at), which was then used as an indicator of the effects of light/dark cycle (ld) perturbations on the temporal pi transport abilities of three species of freshwater algae. ce ... | 1986 | 3083772 |
| hydroperoxide metabolism in cyanobacteria. | the enzymes involved in antioxidative activity and the cellular content of the antioxidants glutathione and ascorbate in the cyanobacteria nostoc muscorum 7119 and synechococcus 6311 have been examined for their roles in hydroperoxide removal. high activities of ascorbate peroxidase and catalase were found in vegetative cells of both species and in the heterocysts of n. muscorum. the affinity of ascorbate peroxidase for h2o2 was 15- to 25-fold higher than that of catalase. increased activity of ... | 1986 | 3083778 |
| interaction of fructose with the glucose permease of the cyanobacterium synechocystis sp. strain pcc 6803. | fructose was bactericidal for the cyanobacterium synechocystis sp. strain pcc 6803. each of ten independently isolated fructose-resistant mutants had an alteration of the glucose transport system, measured as uptake of glucose or of 3-o-methyl-d-glucose. in the presence of the analog, the wild-type synechocystis strain was protected against fructose. two mutants altered in photoautotrophy were also isolated. | 1986 | 3084453 |
| phycobiliprotein-bilin linkage diversity. i. structural studies on a- and d-ring-linked phycocyanobilins. | phycocyanobilin (pcb) peptides alpha-1 pcb and beta-2t pcb were obtained by proteolytic degradation of synechococcus 6301 c-phycocyanin. these peptides were found to have the following sequences. alpha-1 pcb cys(pcb)-ala-arg beta-2t pcb ile-thr-gln-gly-asp-cys(pcb)-ser-ala. the peptides were examined by 1h nmr, circular dichroism spectroscopy, and secondary ion mass spectrometry. the 1h nmr data confirmed that in each case the bilin was attached through a single linkage, a thioether bond between ... | 1986 | 3084489 |
| transformation of the cyanobacterium anacystis nidulans 6301 with the escherichia coli plasmid pbr322. | anacystis nidulans 6301 has been transformed in the light to ampicillin resistance with the plasmid pbr322. permeaplasts prepared by 2-hr treatment of cells with lysozyme and edta are transformed with a 50-fold higher efficiency than that observed for cells. beta-lactamase is present in a. nidulans transformed either with pbr322 or the plasmid pch1 as evidenced by hydrolysis of the beta-lactam ring of nitrocefin in extracts of transformants. beta-lactamase also can be immunoprecipitated from ext ... | 1986 | 3085098 |
| paralytic shellfish poisons produced by the freshwater cyanobacterium aphanizomenon flos-aquae nh-5. | a single filament clonal isolate of aphanizomenon flos-aquae was made from a water bloom sample taken at a small pond near durham, new hampshire, in 1980. when batch cultured the strain was toxic to mice and had an i.p. ld50 of about 5.0 mg/kg. using an extraction procedure originally designed for paralytic shellfish poisons and other neurotoxins of freshwater cyanobacteria, a purification method was developed. the procedure involved acidified water/ethanol extraction of the cells followed by ul ... | 1986 | 3085292 |
| physiological and chemical characterization of cyanobacterial metallothioneins. | techniques have been developed for detection, quantitation, and isolation of bacterial metallothioneins (mts) from cyanobacterial species. these methods involve differential pulse polarography and reverse-phase high-performance liquid chromatography (hplc) and have allowed detection of picomole quantities of these high sulfhydryl content proteins. the prokaryotic molecule was found to be induced in the presence of cd or zn salts with regulation at the level of transcription. cu was not found to ... | 1986 | 3086079 |
| genetic mapping of the chromosome of the cyanobacterium, anabaena variabilis. proximity of the structural genes for nitrogenase and ribulose-bisphosphate carboxylase. | a cosmid library of dna from the chromosome of the nitrogen-fixing cyanobacterium, anabaena variabilis, has been organized into about 40 linkage groups on the basis of cosmid-cosmid hybridization. nitrogenase and ribulose-bisphosphate carboxylase are protein complexes that are, respectively, active in heterocysts and absent from vegetative cells, and active in vegetative cells and absent from heterocysts. the structural genes for the proteins of these two complexes are found to be in close proxi ... | 1986 | 3086317 |
| genes encoding major light-harvesting polypeptides are clustered on the genome of the cyanobacterium fremyella diplosiphon. | the polypeptide composition of the phycobilisome, the major light-harvesting complex of prokaryotic cyanobacteria and certain eukaryotic algae, can be modulated by different light qualities in cyanobacteria exhibiting chromatic adaptation. we have identified genomic fragments encoding a cluster of phycobilisome polypeptides (phycobiliproteins) from the chromatically adapting cyanobacterium fremyella diplosiphon using previously characterized dna fragments of phycobiliprotein genes from the eukar ... | 1986 | 3086870 |
| the pharmacology of anatoxin-a(s), a neurotoxin produced by the freshwater cyanobacterium anabaena flos-aquae nrc 525-17. | anatoxin-a(s) [antx-a(s)] is produced by anabaena flos-aquae clone nrc 525-17 and is different from anatoxin-a, a known depolarizing agent produced by a. flos-aquae nrc 44-1. purification of antx-a(s) from lyophilized cells involved extraction with 1.0 m acetic acid: ethanol (80:20), column chromatography (sephadex g-15 and cm-sephadex c-25) and high performance liquid chromatography. purified toxin has an ld50 (i.p., mouse) of approximately 50 micrograms/kg. gross pharmacological tests of antx- ... | 1986 | 3087030 |
| identification of a carotenoid-binding protein in the cytoplasmic membrane from the heterotrophic cyanobacterium synechocystis sp. strain pcc6714. | we isolated a carotenoid-binding protein from the cytoplasmic membrane of the cyanobacterium synechocystis sp. strain pcc6714. the polypeptide demonstrated a characteristic mobility shift when electrophoresed in lithium dodecyl sulfate-polyacrylamide gels. the protein migrated with an apparent molecular mass of 35 kilodaltons when solubilized at 0 degrees c, but after solubilization at 70 degrees c, the protein migrated as a 45-kilodalton species. the carotenoid-binding protein accumulated only ... | 1986 | 3087963 |
| expression of luciferases from vibrio harveyi and vibrio fischeri in filamentous cyanobacteria. | shuttle vectors that had previously been shown to replicate both in escherichia coli and in strains of anabaena spp. were used to transfer the lux genes from vibrio harveyi and vibrio fischeri into anabaena spp. the level of expression of luciferase in the cyanobacteria (up to 7,000 quanta cell-1 s-1) makes these genes good candidates for use as promoter probes during the differentiation of certain cells in a filament into heterocysts. | 1986 | 3087964 |
| freeze-fracture analysis of thylakoid membranes and photosystem i and ii enriched fractions from phormidium laminosum. | thylakoid membranes of the thermophilic cyanobacterium phormidium laminosum have been fractionated into photosystem ii and photosystem i particles. these fractions have been characterized by their partial electron transport activities, and biochemical and spectral properties. exoplasmic fracture face and protoplasmic fracture face particles in the unfractionated thylakoid membranes were shown to correspond in size to particles in freeze-fractured photosystem ii and photosystem i fractions, respe ... | 1986 | 3088002 |
| mutagenesis by ethidium bromide, proflavine and mitomycin c in the cyanobacterium nostoc sp. | ethidium bromide, proflavine, and mitomycin c were strongly lethal but weakly mutagenic to the cyanobacterium nostoc sp. with a view to studying the mode of action of these weak mutagens, their binding to nostoc dna was studied. the spectral changes resulting from the binding of these mutagens to the dna in vitro indicated that probably only electrostatic forces may be involved in the mutagen-dna binding. a similar low level of dna binding in vivo would explain the weakly mutagenic action of the ... | 1986 | 3088444 |
| studies on environmental chemical carcinogenesis in japan. | the historical background of studies in japan on chemical carcinogenesis from environmental sources is described from personal experience. | 1986 | 3088728 |
| characterization of cyanobacterial ferredoxin-nadp+ oxidoreductase molecular heterogeneity using chromatofocusing. | chromatofocusing has been used as an analytical tool to check preparations of the enzyme ferredoxin-nadp+ oxidoreductase (ec 1.18.1.2) purified in either the presence or absence of the serine protease inhibitor phenylmethylsulfonyl fluoride from the cyanobacterium anabaena sp. strain 7119. only one isoelectric species was found when the crude extract was processed in the presence of the protease inhibitor. nevertheless, when the inhibitor was omitted, four ionic forms of the enzyme--showing appa ... | 1986 | 3089056 |
| purification, properties, and oligomeric structure of glutathione reductase from the cyanobacterium spirulina maxima. | glutathione reductase [nad(p)h:gssg oxidoreductase ec 1.6.4.2] from cyanobacterium spirulina maxima was purified 1300-fold to homogeneity by a simple three-step procedure involving ammonium sulfate fractionation, ion exchange chromatography on deae-cellulose, and affinity chromatography on 2',5'-adp-sepharose 4b. optimum ph was 7.0 and enzymatic activity was notably increased when the phosphate ion concentration was increased. the enzyme gave an absorption spectrum that was typical for a flavopr ... | 1986 | 3089164 |
| role of the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase in the activation process. | the large (a) and small (b) subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase (ec 4.1.1.39) from the cyanobacterium aphanothece halophytica and from the purple sulfur photosynthetic bacterium chromatium vinosum (strain d) were separated by sucrose density gradient centrifugation at low ionic strength and alkaline ph (9.3), respectively. it was found that subunit b enhances the extent of activation by co2 and mg2+ at equilibrium of the two homologous enzymes consisting of aphanothece la ... | 1986 | 3089168 |
| influence of very low doses of ionizing radiation on synechococcus lividus metabolism during the initial growth phase. | previous results from this laboratory have shown that very low chronic doses of gamma radiation can stimulate proliferation of the cyanobacterium synechococcus lividus. this modification of cell proliferation occurred during the first doubling. in this paper, we have compared the metabolism of cells cultivated in a normal environment or under chronic irradiation. incubation of the cells in a new medium induced a high superoxide dismutase (ec 1.15.1.1, sod) activity at the 18th hour and a degrada ... | 1986 | 3089188 |
| the use of nickel to probe the role of hydrogen metabolism in cyanobacterial nitrogen fixation. | the hydrogenase activities of the heterocystous cyanobacteria anabaena cylindrica and mastigocladus laminosus are nickel dependent, based on their inability to consume hydrogen with various electron acceptors or produce hydrogen with dithionite-reduced methyl viologen, after growth in nickel-depleted medium. upon addition of nickel ions to nickel-deficient cultures of a. cylindrica, the hydrogenase activity recovered in a manner which was protein synthesis-dependent, the recovery being inhibited ... | 1986 | 3089304 |
| hydrogenase activities in cyanobacteria. | in the unicellular anacystis nidulans, the expression of both the h2-uptake (with phenazine methosulfate or methylene blue as the electron acceptor) and h2-evolution (with methyl viologen reduced by na2s2o4) was dependent on ni in the culture medium. in extracts from anacystis and anabaena 7119, h2-evolution and uptake activities were strongly inhibited by cu2+, p-chloromercuribenzoate and hgcl2 suggesting that at least one functional sh-group is involved in catalysis by hydrogenase. extracts fr ... | 1986 | 3089305 |
| cadmium transport, resistance, and toxicity in bacteria, algae, and fungi. | cadmium is an important environmental pollutant and a potent toxicant to bacteria, algae, and fungi. mechanisms of cd toxicity and resistance are variable, depending on the organism. it is very clear that the form of the metal and the environment it is studied in, play an important role in how cd exerts its effect and how the organism(s) responds. a wide range of cd concentrations have been used to designate resistance in organisms. to date, no concentration has been specified that is applicable ... | 1986 | 3089567 |
| reaction intermediate partitioning by ribulose-bisphosphate carboxylases with differing substrate specificities. | the carboxylated, 6-carbon reaction intermediate (3-keto-2-carboxyarabinitol 1,5-bisphosphate) from the ribulose-1,5-bisphosphate carboxylase reaction was obtained by denaturing the enzyme with acid during steady-state turnover. carbon-13 nmr analysis indicates that this beta-keto acid exists in solution predominantly as the c-3 ketone (as opposed to the hydrate) form. in neutral solution the intermediate slowly decomposes (t1/2 approximately 1 h) by decarboxylation. this decarboxylation reactio ... | 1986 | 3090034 |
| crystal structure analysis and refinement at 2.5 a of hexameric c-phycocyanin from the cyanobacterium agmenellum quadruplicatum. the molecular model and its implications for light-harvesting. | the crystal structure of the light-harvesting protein-pigment complex c-phycocyanin from the cyanobacterium agmenellum quadruplicatum has been determined by patterson search techniques on the basis of the molecular model of c-phycocyanin from mastigocladus laminosus. the crystal unit cell (space group p321) contains three (alpha beta)6 hexamers centred on the crystallographic triads. the hexamer at the origin of the unit cell exhibits crystallographic 32 point symmetry. the other two hexamers (i ... | 1986 | 3090271 |
| mass mortality of bats due to probable blue-green algal toxicity. | | 1986 | 3090284 |
| functional linkage between phycobilisome and reaction center in two phycobilisome oxygen-evolving photosystem ii preparations isolated from the thermophilic cyanobacterium synechococcus sp. | photosystem ii oxygen-evolving preparations with attached phycobilisomes were isolated from the thermophilic cyanobacterium synechococcus sp. with beta-octylglucoside or digitonin. fluorescence emission spectra of the two preparations determined at 77 k largely lacked a far red band which originates from photosystem i. the spectrum of the digitonin preparation was otherwise similar to that of intact cells, whereas the beta-octylglucoside preparation showed a pronounced band at 687 nm, which is c ... | 1986 | 3090938 |
| involvement of sulfatide in activation of protein kinase c by tumor promoters. | sulfatide (cerebroside sulfate) activated protein kinase c to the same extent as phosphatidylserine did with the tumor promoters, 12-o-tetradecanoylphorbol-13-acetate (tpa), teleocidin and debromoaplysiatoxin. sulfatide and phosphatidylserine both induced specific binding of [3h]tpa to protein kinase c, although the ratios of specific to non-specific [3h]tpa binding to protein kinase c with the two were not the same. it is concluded that sulfatide is involved in activation of protein kinase c by ... | 1986 | 3091011 |
| heterospecific transformation among cyanobacteria. | heterospecific transformation occurred between cyanobacteria currently classified in either the genus synechococcus or synechocystis. cyanobacterial strains 73109 and 6906 were capable of physiological transformation. | 1986 | 3091578 |
| immunological characterization of photosystem ii chlorophyll-binding proteins from the cyanobacterium, aphanocapsa 6714. | chlorophyll-binding proteins from the cyanobacterium aphanocapsa 6714 were identified by immunoblotting procedures. three chlorophyll-binding complexes, cpiii', cpiiia, and cpiiib, were associated with psii. cpiii' likely serves as an' antenna to psii in aphanocapsa since it could be removed from active psii core preparations without loss of activity. the cpiii' proteins cross-reacted to antibodies prepared against the maize psii light-harvesting complex, lhc-ii. the cpiiia polypeptides cross-re ... | 1986 | 3091588 |
| milk and arteriosclerosis. | milk consumption is related to arteriosclerosis. recent landmark studies confirm a previously suspected close correlation between milk intake and arteriosclerotic heart disease. support is therefore provided for a recently proposed novel hypothesis that arteriosclerosis is a chronic infectious disease caused by blue-green bacteria and that milk is a carrier vehicle for these contaminant organisms. a revisionist view of diet and milk in the causation of arteriosclerosis is developed. previous hyp ... | 1986 | 3091997 |
| linker polypeptides of the phycobilisome from the cyanobacterium mastigocladus laminosus. i. isolation and characterization of phycobiliprotein-linker-polypeptide complexes. | phycobilisomes from the cyanobacterium mastigocladus laminosus cultured in white and red light were isolated and compared with respect to the phycoerythrocyanin (pec) and linker polypeptide contents. it was verified that the production of pec is induced by low light intensities. a pec complex, (alpha pec beta pec)6lr34.5,pec, and a phycocyanin (pc) complex, (alpha pc beta pc)6lr34.5,pc, were isolated from phycobilisomes by cellex-d anion exchange chromatography and sucrose density gradient centr ... | 1986 | 3092840 |
| linker polypeptides of the phycobilisome from the cyanobacterium mastigocladus laminosus. ii. amino-acid sequences and functions. | the complete primary structure of an 80-residue linker polypeptide, lr(c)8.9, from the phycobilisome of the cyanobacterium mastigocladus laminosus was determined as well as the 44 n-terminal residues of the two linker polypeptides lr34.5,pec and lr34.5,pc and the 114 c-terminal residues of lr34.5,pec. a brief description of the structure determination and an extensive discussion of the relationships of these polypeptides have been published recently (füglistaller, p., suter, f. & zuber, h. (1985 ... | 1986 | 3092841 |
| the complete amino-acid sequence of c-phycoerythrin from the cyanobacterium fremyella diplosiphon. | the amino-acid sequences of both subunits of c-phycoerythrin from the cyanobacterium fremyella diplosiphon have been determined. the alpha-subunit contains 164 amino acid residues, two phycoerythrobilin (peb) chromophores and has a molecular mass of 18,368 da (protein: 17,192 da + 2 peb, one peb accounting for 588 da). the beta-subunit consists of 184 residues, three peb chromophores and has a molecular mass of 20,931 da (protein: 19,168 da and 3 peb: 1,764 da). the five peb chromophores (open c ... | 1986 | 3092842 |
| purification and characterization of phosphoenolpyruvate carboxylase from a cyanobacterium. | phosphoenolpyruvate (pep) carboxylase (ec 4.1.1.31) was purified 100-fold from the cyanobacterium coccochloris peniocystis with a yield of 10%. a single isozyme was found at all stages of purification, and activity of other beta-carboxylase enzymes was not detected. the apparent molecular weight of the native enzyme was 560,000. optimal activity was observed at ph 8.0 and 40 degrees c, yielding a vmax of 8.84 mumol/mg of protein per min. the enzyme was not protected from heat inactivation by asp ... | 1986 | 3093461 |
| characterization of dna uptake by the cyanobacterium anacystis nidulans. | the binding and uptake of nick-translated 32p-labeled pbr322 by anacystis nidulans 6301 have been characterized. both processes were considerably enhanced in permeaplasts compared to cells. the breakdown of labeled dna was not correlated with binding or uptake by permeaplasts or cells. uptake of dna by permeaplasts was unaffected by: mg2+ or ca2+, light, or inhibitors of photophosphorylation such as valinomycin or gramicidin d in the presence or absence of nh4cl. atp at 2.5-10 mm inhibited both ... | 1986 | 3093820 |
| [the origin of the eukaryotic cell. ii. a critical analysis of the symbiotic (exogenous) concept]. | the exogenous (symbiotic) conception of the eukaryotic cell origin is unable to explain satisfactory the structure of mitochondria and chloroplasts. either of these organelles possess its genome that can be compared with the viral one rather than with the bacterial one, judging by the dimensions and quantity of coding genes. the mitochondria resemble a little prokaryotes in the number of their proteins, chemical composition of their inner membrane and peculiarities of the protein-synthesizing ap ... | 1986 | 3094213 |
| production, by filamentous, nitrogen-fixing cyanobacteria, of a bacteriocin and of other antibiotics that kill related strains. | colonies of sixty-five filamentous cyanobacteria were screened for the production of temperate phages and/or antibiotics on solid medium. none of them was observed to release phages. however, seven n2-fixing strains were found to produce antibiotics very active against other cyanobacteria. the antibiotic produced by nostoc sp. 78-11a-e represents a bacteriocin of low molecular weight. nostoc sp. atcc 29132 appears to secrete, together with an antibiotic, a protein that inhibits its action. | 1986 | 3094472 |
| isolation of cyanobacterial heterocysts with high and sustained dinitrogen-fixation capacity supported by endogenous reductants. | a method is described for the preparation of cyanobacterial heterocysts with high nitrogen-fixation (acetylene-reduction) activity supported by endogenous reductants. the starting material was anabaena variabilis atcc 29413 grown in the light in the presence of fructose. heterocysts produced from such cyanobacteria were more active than those from photoautotrophically-grown a. variabilis, presumably because higher reserves of carbohydrate were stored within the heterocysts. it proved important t ... | 1986 | 3094473 |
| proline inhibits n2-fixation in anabaena 7120. | the uptake and metabolism of proline by anabaena 7120 is demonstrated. uptake is linear over the first hour and it appears that the rate of proline oxidation is sufficient to account for growth is suggested by the finding that exogenous proline represses heterocyst differentiation and inhibits nitrogen fixation in anabaena 7120, without affecting growth rate. | 1986 | 3094529 |
| transformation in cyanobacteria. | the lack of any known transduction or indigenous conjugation systems has left transformation as the major means for genetic manipulations in cyanobacteria. studies of transformation in cyanobacteria generally have dealt with one of two distinct areas. the first area is genomic transformation where internalized donor dna recombines with chromosomally located genes. chromosomal transformation can be a powerful tool for genetic mapping and mutagenesis. the second area is plasmid transformation wher ... | 1986 | 3095029 |
| pheromones among the procaryotes. | a pheromone is a chemical excreted by an organism into the environment that acts to elicit a specific response from other organisms of the same species. the importance of pheromones in the life cycle of various species of mammals, insects, and fungi is well known. in the past decade, it has become apparent that pheromones influence the behavior and development of prokaryotes. pheromones excreted by myxobacteria, actinomycetes, and cyanobacteria elicit specific developmental responses from these ... | 1986 | 3095030 |
| use of freshly prepared rat hepatocytes to study toxicity of blooms of the blue-green algae microcystis aeruginosa and oscillatoria agardhii. | extracts from blue-green algal blooms (microcystis aeruginosa and oscillatoria agardhii) from different lakes in southeastern norway were tested for toxicity toward freshly prepared rat hepatocytes. the toxicity effects were scored by means of morphological studies of the cells and by measuring leakage of the enzyme lactate dehydrogenase (ldh) from the cells. the results with the hepatocytes correspond well with results from the traditional mouse bioassay, concerning both ability to distinguish ... | 1986 | 3095554 |
| coding sequence of a ferredoxin gene from anabaena variabilis atcc 29413. | | 1986 | 3095790 |
| coding sequence of a ferredoxin gene from anacystis nidulans r2 (synechococcus pcc7942). | | 1986 | 3095791 |
| organization of the genes for nitrogen fixation in photosynthetic bacteria and cyanobacteria. | | 1986 | 3096194 |
| molecular cloning of the phosphoenolpyruvate carboxylase gene of anabaena variabilis. | purified anabaena variabilis chromosomal dna was partially digested with restriction endonuclease sau3a and ligated into the bamhi site of plasmid pbr322. escherichia coli 342-167, a mutant with a decreased level of phosphoenolpyruvate carboxylase (pepcase) activity was transformed with plasmids from the a. variabilis genomic library. a transformant that grew on minimal media in the absence of glutamate was isolated and its plasmid, ptrh1, was shown to encode the a. variabilis pepcase. e. coli h ... | 1986 | 3096819 |
| polysaccharide covalently linked to the peptidoglycan of the cyanobacterium synechocystis sp. strain pcc6714. | a polysaccharide was found to be covalently linked to the peptidoglycan of the unicellular cyanobacterium synechocystis sp. strain pcc6714 via phosphodiester bonds. it could be cleaved from the peptidoglycan-polysaccharide (pg-ps) complex by hydrofluoric acid (hf) treatment in the cold (48% hf, 0 degrees c, 48 h) yielding a pure, hf-insoluble peptidoglycan fraction and an hf-soluble polysaccharide fraction. the pg-ps complex was isolated from the triton x-100-insoluble cell wall fraction by hot ... | 1986 | 3096958 |
| cloning, expression, and characterization of the anabaena thioredoxin gene in escherichia coli. | the gene encoding thioredoxin in anabaena sp. strain pcc 7119 was cloned in escherichia coli based on the strategy that similarity between the two thioredoxins would be reflected both in the gene sequence and in functional cross-reactivity. dna restriction fragments containing the anabaena thioredoxin gene were identified by heterologous hybridization to the e. coli thioredoxin gene following southern transfer, ligated with puc13, and used to transform an e. coli strain lacking functional thiore ... | 1986 | 3096973 |
| isolation and nucleotide sequence analysis of the ferredoxin i gene from the cyanobacterium anacystis nidulans r2. | two mixed oligonucleotide probes derived from conserved regions of the synechocystis sp. strain pcc 6714 ferredoxin amino acid sequence were utilized to isolate an anacystis nidulans r2 clone containing the ferredoxin i gene. nucleotide sequence analysis revealed a 297-base-pair (bp) open reading frame with a deduced amino acid sequence having high homology to other cyanobacterial ferredoxins. assuming proteolytic cleavage of the initial methionine residue, the molecular weight of the mature a. ... | 1986 | 3096975 |
| role of phycoerythrin in marine picoplankton synechococcus spp. | | 1986 | 3097824 |
| possibilities of biological energy production. | from the numerous possibilities of biological solar energy transduction the production of hydrogen was selected in our laboratory. there are two forms of h2 production: from biomass with enzymes (formate-hydrogen lyase and hydrogenase enzymes) and the exploitation of some living systems or their analogs to evolve h2 from water upon solar irradiation. to approach the first problem, a bacterial strain and a hydrogenase (h2ase) enzyme of good parameters were isolated. the system composed produced h ... | 1986 | 3098012 |
| complete amino acid sequence of cyanobacterial gas-vesicle protein indicates a 70-residue molecule that corresponds in size to the crystallographic unit cell. | gas vesicles of cyanobacteria are formed by a protein called 'gas-vesicle protein' (gvp). the complete amino acid sequence has been determined of gvp from anabaena flos-aquae. it is 70 residues long and has an mr of 7388. this corresponds to the size of the repeating unit cell demonstrated by x-ray crystallography of intact gas vesicles. details of the sequence are related to the secondary beta-sheet structure of the protein and its contrasting hydrophilic and hydrophobic surfaces. extensive ami ... | 1986 | 3098234 |
| expression of a family of psba genes encoding a photosystem ii polypeptide in the cyanobacterium anacystis nidulans r2. | the genome of the cyanobacterium anacystis nidulans r2 contains three genes (psba) for the qb protein of photosystem ii. this protein is essential for oxygenic photosynthetic electron tansport, and is the target for several herbicides which act by binding directly to the photosynthetic apparatus. transcripts from the three anacystis psba genes are present in wild-type cells at different steady-state levels. the nucleotide sequences of two of the genes, psbaii and psbaiii, predict a protein havin ... | 1986 | 3098559 |
| mutations that affect structure and assembly of light-harvesting proteins in the cyanobacterium synechocystis sp. strain 6701. | the unicellular cyanobacterium synechocystis sp. strain 6701 was mutagenized with uv irradiation and screened for pigment changes that indicated genetic lesions involving the light-harvesting proteins of the phycobilisome. a previous examination of the pigment mutant uv16 showed an assembly defect in the phycocyanin component of the phycobilisome. mutagenesis of uv16 produced an additional double mutant, uv16-40, with decreased phycoerythrin content. phycocyanin and phycoerythrin were isolated f ... | 1987 | 3098729 |
| characterization of the motile hormogonia of mastigocladus laminosus. | the cyanobacterium mastigocladus laminosus produces motile hormogonia which move by gliding motility. these hormogonia were characterized in terms of their morphology, state of differentiation of the cells, optimal temperature for production and motility, minimal nutritional requirements to sustain motility, liberation of the hormogonium from its parental trichome, average surface velocity, and maximal concentration of agar through which the hormogonium may move. we found that an average hormogo ... | 1987 | 3098731 |
| improved preservation of glycogen in unfixed cyanobacteria embedded at -82 degrees c in nanoplast. | a technique is presented for embedding unfixed cells at -82 degrees c in nanoplast, a water-soluble melamine resin. by use of this procedure, improved ultrastructural preservation is demonstrated in cyanobacteria. sections treated in this way are suitable for histochemical techniques such as thiéry's silver staining method for glycogen. | 1987 | 3098832 |
| electron microscopical visualization of presumptive bacterial conjugation channel. preliminary note. | | 1986 | 3099729 |
| fluorescence properties of allophycocyanin and a crosslinked allophycocyanin trimer. | data on the wavelength and temperature dependence of both time-resolved and steady state fluorescence emission are presented for allophycocyanin (ap) and for a crosslinked allophycocyanin trimer (xl-ap) (ong lj and glazer an: physiol veg 23:777-787, 1985). ap dissociates at high dilution and is not stable above 40 degrees c even at moderate protein concentration. in contrast, xl-ap does not dissociate even at very low protein concentrations and is completely stable up to 60 degrees c in the pres ... | 1987 | 3100257 |
| morphological and ultrastructural changes in vegetative cells and heterocysts of anabaena variabilis grown with fructose. | the morphology and ultrastructure of anabaena variabilis grown in medium with and without 40 mm fructose were compared. vegetative cells and young heterocysts in fructose-supplemented medium were significantly larger, were filled with glycogen granules, and had fewer thylakoids. developing heterocysts contained large numbers of glycogen granules well into mature stages, and envelope formation was precocious. as heterocysts enlarged in fructose medium, their shape became more broadly oblong compa ... | 1987 | 3100507 |
| freshly prepared rat hepatocytes used in screening the toxicity of blue-green algal blooms. | the acute toxicity of extracts of blue-green algae was tested in freshly prepared rat hepatocytes in suspension. the results were compared with the traditional in vivo mouse bioassay. sixty samples of natural algal blooms from freshwater lakes in norway, sweden, and finland and 14 samples cultured in the laboratory were tested. the mouse bioassay revealed hepatotoxins in a large number of the algae, while neurotoxins were not found. acute hepatotoxicity in vitro was scored by measurement of leak ... | 1987 | 3100818 |
| preirradiation of medium induces a subsequent stimulation or inhibition of growth according to the physiological state in synechococcus lividus in culture. | the proliferation of synechococcus lividus cells grown in preirradiated medium was compared with the proliferation of cells grown in a shielded or freshly prepared medium. aging of medium in a shielded chamber resulted in a slight inhibiting effect on growth in every phase of the cell cycle which was used. preirradiation of medium resulted in a stimulation of growth observed on day 7 in cultures inoculated with cells selected in the deceleration phase and an inhibition of growth in cultures inoc ... | 1987 | 3101134 |
| sorption of low-level radwaste by spirulina. | the feasibility of using spirulina as adsorbent for the treatment of low-level liquid radwaste is studied. the experimental results indicate that the sorption capacity of spirulina is good for the di- and trivalent metallic ions at ph 3-7, but rather poor for the mono-valent metallic ions and non-metallic ions. some factors affecting metal ion uptake by spirulina such as the content of detergent, sodium ion in liquid radwaste and the stability of spirulina under gamma irradiation were also inves ... | 1986 | 3101144 |
| toxic peptides from freshwater cyanobacteria (blue-green algae). i. isolation, purification and characterization of peptides from microcystis aeruginosa and anabaena flos-aquae. | toxic peptides from two european microcystis aeruginosa and one canadian anabaena flos-aquae species of freshwater cyanobacteria (blue-green algae) were purified by high performance liquid chromatography (hplc) and examined by amino acid analysis and mass spectrometry. a toxic fraction from a butanol/methanol extract of toxic lyophilized cells was separated by g-25 gel filtration and purified by hplc using a c-18 semi-preparative column. a toxic peak with the same elution time was detected for e ... | 1986 | 3101230 |
| organization of genes for ribosomal proteins s7 and s12, elongation factors ef-tu and ef-g in the cyanobacterium spirulina platensis. | the gene encoding ribosomal proteins s12 and probably s7 as well as protein synthesis elongation factors tu (ef-tu) and g (ef-g) of spirulina platensis have been identified and cloned. gene expression was determined for ribosomal protein s12 by genetic complementation of the appropriate escherichia coli mutant, whereas for the ef-tu gene it was determined by production of the protein in e. coli minicells. on the basis of these experiments we suggest the following gene order in the s. platensis c ... | 1987 | 3101737 |
| alteration of nitrogenase activity of anabaena ch1 and ch2 during light-dark transition. | nitrogenase activity decreased as cultures transferred from light to the dark. in anabaena ch1 nitrogenase activity ceased to near zero in two hours; but it took longer in anabaena ch2. when darkened culture was placed again in the light, nitrogenase activity recovered in two hours. hydrogen gas could protect this dark declination of nitrogenase activity. it is suggested that dark declination of nitrogenase activity is due to irreversible inhibition by oxygen which can not be omitted through oxi ... | 1986 | 3102178 |
| nitrogen starvation mediated by dl-7-azatryptophan in the cyanobacterium anabaena sp. strain ca. | the addition of dl-7-azatryptophan (azat), a tryptophan analog, to continuous cultures of anabaena sp. strain ca grown with 10 mm nitrate as the nitrogen source resulted in the differentiation of heterocysts. analysis of the intracellular amino acid pools of anabaena sp. strain ca after the addition of azat showed a marked decline in the intracellular glutamate pool and a slight increase in the levels of glutamine. the in vitro activity of glutamate synthase, the second enzyme involved in primar ... | 1987 | 3102456 |
| asymmetrical core structure in phycobilisomes of the cyanobacterium synechocystis 6701. | the light-harvesting complex of cyanobacteria and red algae, the phycobilisome, has two structural domains, the core and the rods. both contain biliproteins and linker peptides. the core contains the site of attachment to the thylakoid membrane and the energy transfer link between the phycobilisome and chlorophyll. there are also six rod-binding sites in the membrane-distal periphery of the core. the structure of phycobilisomes in the cyanobacterium synechococcus 6301 was studied by glazer, who ... | 1986 | 3102748 |
| the phycobiliprotein beta 16.2 of the allophycocyanin core from the cyanobacterium mastigocladus laminosus. characterization and complete amino-acid sequence. | the minor phycobiliprotein beta 16.2 was isolated from the apc-core of phycobilisomes from the cyanobacterium mastigocladus laminosus. its complete amino-acid sequence and some spectral characteristics are presented. beta 16.2 consists of 169 amino acids and its molecular mass is 19,390 da. a phycocyanobilin chromophore is covalently bound to a cysteine at position 84 as in all other phycobiliproteins. the first 138 amino acids are highly homologous to the n-terminal part of beta ap (62.5%), whe ... | 1987 | 3103645 |
| kinetics of allophycocyanin's trimer-monomer equilibrium. | kinetic studies of the dissociation of allophycocyanin trimers to monomers have been performed by using stopped-flow techniques. the dissociation was monitored by two techniques: by light scattering to observe the molecular weight changes directly and by 650-nm absorbance to observe the linkage of quaternary structure to spectra. the light-scattering experiments showed a simple exponential decay of trimers to monomers with a dissociation constant of 0.23 s-1. the absorption changes were complex, ... | 1987 | 3103679 |
| molecular aspects of nitrogen fixation by photosynthetic prokaryotes. | the photosynthetic prokaryotes possess diverse metabolic capabilities, both in carrying out different types of photosynthesis and in their other growth modes. the nature of the coupling of these energy-generating processes with the basic metabolic demands of the cell, such as nitrogen fixation, has stimulated research for many years. in addition, nitrogen fixation by photosynthetic prokaryotes exhibits several unique features; the oxygen-evolving cyanobacteria have developed various strategies f ... | 1987 | 3103981 |
| photosensory behavior in procaryotes. | | 1987 | 3104747 |
| nucleotide sequence of phycocyanin beta-subunit gene of cyanobacterium anacystis nidulans strain r2. | | 1987 | 3104880 |
| regulated synthesis of phycobilisome components. | | 1986 | 3104939 |
| observations of toxic blue-green algae (cyanobacteria) in some scandinavian lakes. | | 1986 | 3105274 |
| influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation. | investigations carried out on the protozoan paramecium tetraurelia and the cyanobacteria synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). the stimulatory effect occurred only in a limited range of doses and disappeare ... | 1987 | 3106264 |
| functional expression of plastid allophycocyanin genes in a cyanobacterium. | in cyanophora paradoxa, the allophycocyanin apoprotein subunits, alpha and beta, are encoded in the cyanelle (plastid) genome. these genes were transferred to the cyanobacterium synechococcus sp. pcc 7002 on a plasmid replicon. phycobilisomes isolated from transformed cyanobacteria were found to contain c. paradoxa allophycocyanin subunits. thus, these plastid genes are expressed in the cyanobacterium as polypeptides which become linked to a chromophore and are incorporated into the light-harves ... | 1987 | 3106320 |
| a rapid analysis of water for anatoxin a, the unstable toxic alkaloid from anabaena flos-aquae, the stable non-toxic alkaloids left after bioreduction and a related amine which may be nature's precursor to anatoxin a. | poisoning of animals by anabaena flos-aquae alkaloid is a common, but sporadic event (1). anatoxin a is the toxic principle responsible for acute fatalities (2), and tends to disappear along with the toxicity within a few days of the event, thus complicating diagnosis. this report reveals our simplified analytical methodology for anatoxin a (2-acetyl-9-azabicyclo[4.2.1] non-2,3-ene), for the non-toxic compounds into which it bioreduces, the chair and boat forms of 2-acetyl-9-azabicyclo[4.2.1] no ... | 1987 | 3107204 |
| toxic effects of organic solvents on the growth of blue-green algae. | | 1987 | 3107637 |
| influence of light on chlorophyll, a content of blue-green algae treated with heavy metals. | | 1987 | 3107639 |
| alteration of the fe protein of nitrogenase by oxygen in the cyanobacterium anabaena sp. strain ca. | changes in protein composition were noted when heterocysts of anabaena sp. strain ca were isolated from filaments grown in 1% co2-99% n2 and subsequently exposed to oxygen. immunospecific western blot analysis showed that the fe protein of nitrogenase is altered. in cells grown under microaerobic conditions, the fe protein was found in a form with an apparent molecular weight of 30,000. exposure to oxygen caused a shift in the migration of this polypeptide to a position corresponding to an appar ... | 1987 | 3108236 |
| isolation and characterization of light-regulated phycobilisome linker polypeptide genes and their transcription as a polycistronic mrna. | several cyanobacteria adjust both the phycobiliprotein and linker protein composition of the phycobilisome, a light-harvesting complex in cyanobacteria and some eucaryotic algae, to maximize absorption of prevalent wavelengths of light. this process is called complementary chromatic adaptation. we sequenced the amino terminus of a linker polypeptide which is associated with phycocyanin and accumulates to high levels during growth of the cyanobacterium fremyella diplosiphon in red light. a mixed ... | 1987 | 3108238 |
| molecular cloning and characterization of the reca gene from the cyanobacterium synechococcus sp. strain pcc 7002. | the reca gene of synechococcus sp. strain pcc 7002 was detected and cloned from a lambda gtwes genomic library by heterologous hybridization by using a gene-internal fragment of the escherichia coli reca gene as the probe. the gene encodes a 38-kilodalton polypeptide which is antigenically related to the reca protein of e. coli. the nucleotide sequence of a portion of the gene was determined. the translation of this region was 55% homologous to the e. coli protein; allowances for conservative am ... | 1987 | 3108239 |
| regression of experimental hamster cancer by beta carotene and algae extracts. | the effect of algae extract on tumor regression was studied. phycotene (extract of spirulina and dunaliella algae) 250 micrograms in 0.1 ml mem (minimum essential medium) was injected locally into dmba (7, 12 dimethylbenz(a)anthracene)-induced squamous cell carcinomas of hamster buccal pouch in 20 animals. dmba-induced carcinomas in 20 hamsters were injected locally with beta carotene 250 micrograms in 0.1 ml mem; dmba-induced carcinomas in 20 animals were injected locally with canthaxanthin, 25 ... | 1987 | 3108474 |
| cloning and light regulation of expression of the phycocyanin operon of the cyanobacterium anabaena. | the biliprotein phycocyanin (pc) is a major constituent of the light-harvesting apparatus of cyanobacteria and red algae. a dna fragment encoding the beta and alpha subunits of pc was isolated from a genomic library of the cyanobacterium anabaena 7120 dna. the single-copy pc genes are part of a larger operon which consists of five open reading frames (orfs) encoding, in order, the beta and alpha subunits of pc, two linker polypeptides associated with pc in phycobilisome rods, and a fifth orf, wh ... | 1987 | 3109890 |