| muscle sensitivity differences in two avian species to anatoxin-a produced by the freshwater cyanophyte anabaena flos-aquae nrc-44-1. | | 1978 | 417792 |
| pathways of assimilation of [13n]n2 and 13nh4+ by cyanobacteria with and without heterocysts. | the principal initial product of metabolism of [13n]n2 and 13nh4+ by five diverse cyanobacteria is glutamine. methionine sulfoximine inhibits formation of [13n]glutamine except in the case of gloeothece sp., an organism with a thick sheath through which the inhibitor may not penetrate. thus, glutamine synthetase appears to catalyze the initial step in the assimilation of n2-derived or exogenous nh4+ by these organisms. [13n]glutamate is, in all cases, the second major product of assimilation of ... | 1978 | 418057 |
| isolation and properties of fungi that lyse blue-green algae. | of 70 pure microbial cultures isolated from aquatic habitats, soil, and air according to the ability to lyse live blue-green algae, 62 were fungi representing the genera acremonium, emericellopsis, and verticillium. algal-lysing fungi were isolated from all habitat types sampled. the remaining isolates comprised four bacteria and four streptomycetes. all isolates lysed anabaena flos-aquae and, in most cases, several other filamentous and unicellular blue-green algae. the fungi generally showed g ... | 1978 | 418740 |
| effects of low concentrations of bisulfite-sulfite and nitrite on microorganisms. | a wide range of microorganisms was tested to determine their sensitivity to low concentrations of bisulfite-sulfite and nitrite, solubility products of so2 and no2, respectively. photosynthesis by blue-green algae (cyanobacteria) was more strongly inhibited by 0.1 mm bisulfite-sulfite and 1 mm nitrite at ph 6.0 than photosynthesis by eucaryotic algae and respiration of bacteria, fungi, and protozoa. at ph 7.7, blue-green algae were still more sensitive to bisulfite-sulfite and nitrite than eucar ... | 1978 | 646357 |
| [isolation, fractionation and comparative analysis of the cell membranes of the cyanobacterium, anabaena variabilis]. | a homogenate prepared from the protoplasts of anabaena variabilis was fractionated by differential centrifugation and zonal electrophoresis. four subcellular fractions were isolated and characterized with respect to their composition and morphology, two of them being of the membranous nature. membrane visicles from the light, chlorophyll-containing fraction were identified as small fragments of thylakoids while the pigment-deficient, heavy membrane fraction seemed to be represented by fragments ... | 1978 | 672686 |
| toxicology and pharmacological action of anabaena flos-aquae toxin. | calves, rats, ducks, and goldfish given lethal oral doses of bacteria-free lyophilized cell suspensions of toxic anabaena flos-aquae died as a result of respiratory arrest. experiments with selected animals and pharmacological preparations showed that the main effect of the toxin was production of a sustained postsynaptic depolarizing neuromuscular blockade. | 1975 | 803708 |
| mutants of anabaena cylindrica altered in heterocyst spacing. | nitrosoguanidine induced mutants of anabaena cylindrica have been obtained, which are altered in heterocyst spacing. in the wild type organism the pattern is composed of single intercalary heterocysts. the mutant patterns fall into several classes: those with only terminal heterocysts, with both terminal and intercalary heterocysts, with groups of heterocysts and those totally lacking heterocysts. the mutants are described in detail, and the various pattern modications are interpreted in terms ... | 1975 | 807173 |
| effect of pesticides on blue-green algae and nitrogen-fixation. | the effects of the pesticides, amitrol, a derivative of amitrol (viz. 3,5-diamino-1,2,4-triazole), diquat, paraquat, linuron, mcpa, malathion, and monuron, were studied on the nitrogen-fixing algae, anabaena cylindrica, aulosira sp., calothrix elenkenii. chlorogloeae frischii, cylindrospermum muscicola, nostoc sp. from collema tenax, nostoc muscorum tolypothrix tenuis, and westiellopsis sp. in general, two types of response were discernible; an initial period of depression succeeded by an increa ... | 1975 | 808179 |
| allophycocyanin b (lambdamax 671, 618 nm): a new cyanobacterial phycobiliprotein. | a hitherto undescribed red fluorescent phycobiliprotein (maximum emission at congruent to 680 nm), characterized by long wavelength absorption maxima in the visible region at 671 nm (xi = 172000 m(-1).cm(-1) per monomer of mol. wt. 30600)and 618 nm, has been purified to homogeneity from unicellular cyanobacterium, synechococcus sp., and from a filamentous cyanobacterium, anabaena variabilis. the name allophycocyanin b has been proposed for the new protein. a. variabilis allophycocyanin b is ch ... | 1975 | 808186 |
| the intracellular localization of the glycollate-oxidising enzyme of anabaena cylindrica. | | 1975 | 808429 |
| [electron microscopic and biochemical study of spheroplasts of the blue-green alga anabaena variabilis]. | electron microscopy of the spheroplasts of the blue-green alga anabaena variabilis revealed damages induced by lysozyme. biochemical analysis confirmed the data of electron microscopy that the spheroplasts had lost partly the cytoplasmic content of the cells. dna was preserved in the spheroplasts though the nucleoid was not detected by electron microscopy. | 1975 | 808685 |
| [comparative study of the functions of the spheroplasts and cells of the blue-green alga anabaena variabilis]. | the effect of light was studied with the spheroplasts of the blue-green alga anabaena variabilis. contrary to the intact cells, the spheroplasts did not synthesize nucleic acids and pigments in the light. these components of the spheroplasts were decomposed in the light, and the remaining chlorophyll was incapable of luminescence. the rate of oxygen uptake increased upon the incubation of the spheroplasts in the light. changes of the functions induced by lysozyme in the cells of a. variabilis ar ... | 1975 | 808691 |
| nuclear magnetic resonance studies of the copper binding sites of blue copper proteins: oxidized, reduced, and apoplastocyanin. | proton nuclear resonance spectra at 250 mhz of plastocyanins from spinach (spinacia oleracea) and a blue green alga (anabaena variabilis) are reported. spectra of the reduced plastocyanins contain well-resolved peaks from slowly exchangeable n-h, histidine c2-h tyrosine ring, peptide alpha-ch, and high-field protons. the widths of these peaks indicate that the plastocyanins are monomeric. when the plastocyanins are oxidized, several changes in the spectra are observed including disappearance of ... | 1975 | 809054 |
| [change in the atp content in the cells of anabaena variabilis]. | the content of atp in the cells of anabaena variabilis does not change during one day in the darkness as compared to that in the cells grown in the light, this suggesting the endogenous energy reserve of the cell. the level of atp gradually decreases when the cells are incubated in the darkness during 25 days, but does not reach zero. the content of atp increases for a short period in the light in the cells that have been incubated in the darkness during several days (up to 7 days). on the contr ... | 1975 | 809639 |
| assimilation of citric acid and adipic acid by the blue-green alga anabaena variabilis. | the assimilation of [1,6-14c] citric acid and [1,6-14c] adipic acid by the blue-green alga anabaena variabius was studied in the dark and in the light. citric acid was assimilated in the dark and in the light but adipic acid showed only limited assimilation in the dark. in the light the assimilation of adipic acid did not enhance the growth of the alga at a concentration of 2.85 x 10(-8) m. growth was inhibited at adipic acid concentrations greater than 10(-3) m. analysis of the products of adip ... | 1975 | 810235 |
| production of nutritionally-deficient mutants of the axenic blue-green alga anabaena flos-aquae nrc-44-1 by ultraviolet irradiation. | | 1975 | 810978 |
| the effect of pyruvate on nitrogenase activity in the blue-green alga anabaena cylindrica. | exogenous pyruvate added to cultures of the blue-green alga, anabaena cylindrica stimulated nitrogenase activity (measured by acetylene reduction) only in the dark under low po2 (0.05 atmospheres). under aerobic conditions or in the light, stimulation was absent and replaced by an inhibition of activity above 5 mm added pyruvate. the curve of nitrogenase activity versus oxygen concentration had a similar maximal value of ethylene production with, or without added pyruvate, but in the presence of ... | 1975 | 811189 |
| division of heterocysts in the blue-green alga anabaena doliolum bharadwaja. | | 1975 | 812271 |
| prokaryote-eukaryote relationship and the amino acid sequence of plastocyanin from anabaena variabilis. | the amino acid sequence of plastocyanin from the prokaryotic blue-green alga anabaena variabilis was determined. the protein consists of a single polypeptide chain of 105 residues. the amino acid sequence of the plastocyanin was compared with that of the eukaryotic green alga chlorella fusca and with those of higher-plant plastocyanins. the considerable similarity between the prokaryotic and eukaryotic plastocyanins is discussed. detailed evidence for the sequence of the protein has been deposit ... | 1975 | 812489 |
| the initial organic products of fixation of 13n-labeled nitrogen gas by the blue-green alga anabaena cylindrica. | | 1975 | 812496 |
| carbon dioxide assimilation in blue-green algae: initial studies on the structure of ribulose 1,5-bisphosphate carboxylase. | d-ribulose 1,5-bisphosphate carboxylase was purified from the blue-green alga anabaena cylindrica (lemm) by procedures involving acid precipitation, ammonium sulfate fractionation, and sephadex g-200 gel filtration. the enzyme was homogeneous by the criterion of polyacrylamide disc gel electrophoresis and was a multimer of a single-size polypeptide chain of 54,000 daltons. the carboxylases from four species of blue-green algae (anabaena, nostoc strain mac, agmenellum quadruplicatum strain pr-6, ... | 1976 | 812868 |
| photosynthetic electron transport, atp synthesis and nitrogenase activity in isolated heterocysts of anabaena cylindrica. | isolated heterocysts of the n2-fixing blue-green alga anabaena cylindrica contain the photosystem i components p-700, bound and soluble ferredoxins and ferredoxin-nadp reductase. they also show photosystem i activity being able to photoreduce both methylviologen and nadp when ascorbate + dichlorophenol-indophenol acts as reductant. they photophosphorylate (64 munol atp produced/mg chlorophyll a/h) and carry out oxidative phosphorylation (8.7 munol atp produced/mg chlorophyll a/h). ninety per cen ... | 1976 | 813780 |
| measurement of an inhibitory zone. | an inhibitory zone mechanism generates the heterocyst pattern in anabaena. these inhibitory zones can be measured; we find that they extend about five cells on either side of a heterocyst. we can use our observations to predict with reasonable accuracy which cells in the filaments will differentiate into heterocysts. | 1976 | 814620 |
| the incorporation of nitrogen into products of recent photosynthesis in anabaena cylindrica lemm. | in vivo tracer studies with 14c have been performed to help determine pathways of incorporation of newly assimilated nitrogen into n2-fixing cells of anabaena cylindrica. after photosynthesis in ar: o2:14co2 for 30 min, the addition of n2 or nh+4 resulted in increased rates of 14co2-incorporation both in the light and dark, and in increased incorporation of 14c into amino acids at the expense of sucrose and sugar phosphates. evidence of enhanced sucrose catabolism and increased pyruvate kinase a ... | 1976 | 814876 |
| letter: toxicity to livestock of the blue-green algae anabaena circinalis. | | 1975 | 816341 |
| the polysaccharides from heterocyst and spore envelopes of a blue-green alga. methylation analysis and structure of the backbones. | lindberg's combined gas chromatography-mass spectrometry techniques for the analysis of partially methylated alditol acetate sugar derivatives were used to study the structures of polysaccharides from the envelopes of heterocysts and spores of anabaena cylindrica. polysaccharides from both envelopes are highly branched. glucose, mannose, galactose, and xylose are at terminal positions, whereas glucose and mannose are at internal positions in these polymers. the molar percentages of the 11 partia ... | 1976 | 818084 |
| [characteristics of oxygen metabolism in the obligate phototrophic blue-green alga anabaena variabilis in darkness]. | the rate of endogenous respiration of the cells of anabaena variabilis in the mineral medium in the darkness decreases gradually during 30 to 40 days and is then maintained at a low level. the rate of oxygen uptake was the same in the cells grown in aerobic and anaerobic conditions in the darkness. the ability for oxygen evolution in the light is maintained in the anaerobic cells for a longer time, and the biomass yield and the content of phycocyanin in the cells decrease at a lower rate in anae ... | 1975 | 818482 |
| cyanobacterial dna-binding protein related to escherichia coli hu. | a dna-binding protein has been isolated from two cyanobacteria (blue-green algae): anabaena sp and aphanocapsa sp. it has a molecular weight as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis of about 10,000, is rich in lysine and arginine, and lacks tyrosine, tryptophan, and cysteine. the proteins from both strains show immunological identity with a similar dna-binding protein from escherichia coli, when tested by immunodiffusion with an antiserum prepared against the e. ... | 1976 | 819928 |
| atp pools and transientss in the blue-green alga, anabaena cylindrica. | anabaena cylindrica grown in steady state continuous culture has an extractable atp pool, measured on the basis of the luciferin-luciferase assay of 165 +/- 35 nmoles atp mg chla-1. this pool is maintained by a dynamic balance between the rate of atp synthesis and the rate of atp utilization. phosphorylating mechanisms which can maitain the pool in the short term are total photophosphorylation, cyclic photophosphorylation and oxidative phosphorylation. the alga can maintain its atp pool by switc ... | 1976 | 821448 |
| pathway of nitrogen metabolism after fixation of 13n-labeled nitrogen gas by the cyanobacterium, anabaena cylindrica. | methods have been developed for identifying the pathway of assimilation of n2-derived nitrogen. the products of fixation of 13n-labeled nitrogen gas ([13n]n2), and the distribution of 13n within glutamine, were determined after short periods of labeling (approximately 1 to 120 s) and also in pulse-chase experiments. ammonia, the amide nitrogen of glutamine, and the alpha-amino nitrogen of glutamate, in that order, were the first observed products of fixation of n2 by the cyanobacterium (blue-gre ... | 1976 | 821946 |
| [ribosomes of the blue-green alga anabaena variabilis. sedimentation, density characteristics and analysis of ribosomal rna]. | ribosomes and rrnas were isolated from cells of green-blue alga anabaena variabilis. the sedimentation properties of the ribosomes as well as density, molecular weights and nucleotide composition of rrnas were determined. the ribosomes were found to have the s20,w value equal to 67.2+/-0.4s, whereas those of the ribosome subunits were 48.6+/-0.8 and 29.5+/-1.1s. the buoyant density of the ribosomes in cscl was 1.641+/-+/-0.002 g/cm3; a calculated relative protein content was 35%. the molecular w ... | 1976 | 823982 |
| heterocyst and nitrogenase development in anabaena cylindrica. | the differentiation of filaments of a continuous culture of anabaena cylindrica after removal of fixed nitrogen has been examined. rapid development of proheterocysts (4-5 h) and mature heterocysts (14 h) in an ordered sequence was observed; the development of the latter was concomitant with the onset of nitrogenase activity. commitment times of 2-3 h (proheterocyst) and 5-0 (heterocyst) were measured. evidence is presented that shows that heterocyst development, rather than any product of heter ... | 1976 | 824402 |
| [hydrogen metabolism in anabaena variabilis in the dark]. | cells and extracts of the cyanobacterium anabaena variabilis are capable of hydrogen absorption in the dark in the presence of h-acceptors with various redox potentials. preliminary adaptation of the cells to anaerobic conditions has no effect on the process. a. variabilis can also evolve hydrogen in the dark. reduced methylviologen (rmv), formiate, pyruvate, and glucose may be substrates for hydrogen evolution by the cells. the extracts evolve hydrogen in the presence of rmv, benzylviologen, az ... | 1976 | 824526 |
| the fine structure of striated microtubules and sleeve bodies in several species of anabaena. | | 1976 | 825659 |
| [metabolism and destruction of the blue-green alga anabaena variablis in the dark]. | anabaena variabilis remains viable in the dark, which is accompanied with intensive utilization of the reserve polysaccharide by the cells. the content of protein and rna increases in the cells and incomplete cellular division occurs at the beginning of the culture incubation in the dark. destruction of the intracellular protein and rna begins before all the reserve polysaccharide has been utilized. during the whole period of incubation of the alga in the dark, structural integrity of the cells ... | 1976 | 826765 |
| [photodestruction of the blue-green alga anabaena variablis]. | the effect of light on the cells was studied with the obligate phototrophic blue-green alga anabaena variabilis after its incubation in the dark. incubation of the alga in the dark during two weeks was not essential for the cell reproduction systems in the light. incubation in the dark during 3-4 weeks caused damages in the systems which were however reversible and repaired in the light. longer incubation of the cells in the dark results in irreversible damages of the systems protecting them fro ... | 1976 | 827666 |
| [hydrogen production by the cyanobacterium anabaena variablis in the light]. | light of low intensity (less than or equal to 25-10(5) erg-cm(-2)-sec(-1)) stimulates hydrogen production by cell suspensions of anabaena variabilis in the presence of glucose, pyruvate or formate. the maximum rate of hydrogen production in the presence of these substrates was observed at light intensities of 650, 1400 and 2250 erg-cm(-2)-sec(-1), respectively. the rate of oxygen production by the cells increases while the rate of hydrogen evolution decreases with increase in light intensity (2. ... | 1976 | 827669 |
| characterization and structural properties of the major biliproteins of anabaena sp. | studies are presented of the biliproteins of anabaena sp. this filamentous cyanobacterium contains three major biliproteins. whereas two of these, c-phycocyanin and allophycocyanin, are common to all cyanobacteria, the third, phycoerythrocyanin (gammamax approximately 568 nm) has hitherto not been described and its distribution among cyanobacteria appears to be limited. anabaena variabilis and anabaena sp. 6411 allophycocyanin, c-phycocyanin, and phycoerythrocyanin were purified to homogeneity a ... | 1976 | 828020 |
| heterotrophic micro- and macrocultures of a nitrogen-fixing cyanobacterium. | anabaena variabilis can be cloned in the dark from fragments with one and few cells, with an efficiency of about 40%, on the nitrogen-free medium of allen and arnon solidified with 0.5% agarose and supplemented with 5 mm fructose. the organism can be grown exponentially (tau2 approximately or equal to 36 h) in fermentor cultures in the dark, fixing n2, to a density of greater than 10 g dry weight/l. | 1976 | 828022 |
| the fine structure of a microplate-microtubule array, microfilaments and polyhedral body associated microtubules in several species of anabaena. | a microplate-microtubule array was observed in anabaena sp. (b-378). this structure consists of an arched plate, about 8 nm thick, and various microtubules, 12 nm in diameter and 50 nm long, arranged in rows. the microtubules project at right angles from one side of the plate into the cytoplasm or towards the plasma membrane. up to twelve microplate-microtubule arrays were observed in a single section of a cell. microfilaments, about 2.8 nm in diameter and of undetermined length, were observed i ... | 1976 | 828027 |
| isolation, growth and nitrogen fixation of a gas vacuole-less mutant of the blue-green alga anabaena aphanizomenoides. | mutants with loss of gas vacuoles (gvl-) were isolated from a clonal population of the gas vacuole containing (gvl+) blue-green alga anabaena aphanizomenoides with a spontaneous mutation frequency of 1.7 x 10(-3) in nitrogen-free media. growth and nitrogen fixation of the mutant were slow when compared to the gvl+ parent. both the parent and mutant filaments tolerated 0.02 microgram/ml of streptomycin, and higher concentrations were lethal. the reversion of the mutant towards the parent did not ... | 1976 | 829596 |
| group i permuted intron-exon (pie) sequences self-splice to produce circular exons. | circularly permuted group i intron precursor rnas, containing end-to-end fused exons which interrupt half-intron sequences, were generated and tested for self-splicing activity. an autocatalytic rna can form when the primary order of essential intron sequence elements, splice sites, and exons are permuted in this manner. covalent attachment of guanosine to the 5' half-intron product, and accurate exon ligation indicated that the mechanism and specificity of splicing were not altered. however, be ... | 1992 | 1279519 |
| analysis of the gene encoding the rna subunit of ribonuclease p from cyanobacteria. | the genes encoding the rna subunit of ribonuclease p from the unicellular cyanobacterium synechocystis sp. pcc 6803, and from the heterocyst-forming strains anabaena sp. pcc 7120 and calothrix sp. pcc 7601 were cloned using the homologous gene from anacystis nidulans (synechococcus sp. pcc 6301) as a probe. the genes and the flanking regions were sequenced. the genes from anabaena and calothrix are flanked at their 3'-ends by short tandemly repeated repetitive (strr) sequences. in addition, two ... | 1992 | 1282240 |
| interactions of monocrotophos and quinalphos with anabaena torulosa isolated from rice soil. | the interaction of insecticide combinations of monocrotophos and quinalphos on anabaena torulosa, by the criteria of absorbance (od) and packed cell volume (pcv) of the culture, content of chlorophyll a, phycocyanin, carotenoids, total protein, dna and rna, heterocyst differentiation and nitrogen fixation, were assessed. in general, monocrotophos and quinalphos, in combination, interacted significantly yielding three different responses viz., additive, antagonistic or synergistic. the nature of ... | 1992 | 1283819 |
| cyanobiont diversity within and among cycads of one field site. | limited diversity was found among cyanobionts from a cultivated population of cycads at a field site in florida. all isolates were classified as nostoc but were different from the one nostoc species found in the soil. these cyanobacteria were root endophytes of several plants of zamia integrifolia and one of dioon. the isolates were similar morphologically and in their reactions to four fluorescein isothiocyanate conjugated lectins. electrophoretic protein profiles and zymograms distinguished on ... | 1992 | 1288849 |
| structure of the oxidized long-chain flavodoxin from anabaena 7120 at 2 a resolution. | the structure of the long-chain flavodoxin from the photosynthetic cyanobacterium anabaena 7120 has been determined at 2 a resolution by the molecular replacement method using the atomic coordinates of the long-chain flavodoxin from anacystis nidulans. the structure of a third long-chain flavodoxin from chondrus crispus has recently been reported. crystals of oxidized a. 7120 flavodoxin belong to the monoclinic space group p2(1) with a = 48.0, b = 32.0, c = 51.6 a, and beta = 92 degrees, and one ... | 1992 | 1303762 |
| 14,15n, 13c, 57fe, and 1,2h q-band endor study of fe-s proteins with clusters that have endogenous sulfur ligands. | the benefits of performing endor experiments at higher microwave frequency are demonstrated in a q-band (35 ghz) endor investigation of a number of proteins with [nfe-ms] clusters, n = 2, 3, 4. each protein displays several resonances in the frequency range of 0-20 mhz. in all instances, features are seen near v approximately 13 and 8 mhz that can be assigned, respectively, to "distant endor" from 13c in natural-abundance (1.1%) and from 14n (the delta m1 = +/- 2 transitions); the nuclei involve ... | 1992 | 1311203 |
| complex formation between ferredoxin and ferredoxin-nadp+ reductase from anabaena pcc 7119: cross-linking studies. | ferredoxin-nadp+ reductase and ferredoxin from the cyanobacterium anabaena pcc 7119 have been covalently cross-linked by incubation with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. the covalent adduct, which shows a molecular mass consistent with a 1:1 stoichiometry of the two proteins, maintains nearly 60% of the nadph-cytochrome c reductase activity of the enzyme saturated with ferredoxin and this value is considerably higher than when equimolar amounts of both proteins are assayed. no ter ... | 1992 | 1314539 |
| isolation and sequence analysis of a gene encoding a basic cytochrome c-553 from the cyanobacterium anabaena sp. pcc 7937. | | 1992 | 1320427 |
| transcriptional regulation of the plastocyanin and cytochrome c553 genes from the cyanobacterium anabaena species pcc 7937. | the effect of copper on the levels of plastocyanin (pc) and cytochrome c553 (cyt-c)-specific transcripts from anabaena sp. pcc 7937 was investigated. the addition of copper resulted in a marked increase in pc mrna levels, and a decrease in cyt c mrna levels. thus the functional exchange between pc and cyt c seems to be regulated at the mrna level. the copper-dependent increase in pc and decrease in cyt c mrna levels was abolished when chloramphenicol was added to the cells. this suggests that de ... | 1992 | 1320727 |
| molecular cloning and expression of the gene encoding adp-glucose pyrophosphorylase from the cyanobacterium anabaena sp. strain pcc 7120. | previous studies have indicated that adp-glucose pyrophosphorylase (adpglc ppase) from the cyanobacterium anabaena sp. strain pcc 7120 is more similar to higher-plant than to enteric bacterial enzymes in antigenicity and allosteric properties. in this paper, we report the isolation of the anabaena adpglc ppase gene and its expression in escherichia coli. the gene we isolated from a genomic library utilizes gtg as the start codon and codes for a protein of 48,347 da which is in agreement with the ... | 1992 | 1325205 |
| synthesis of nitrogenase in mutants of the cyanobacterium anabaena sp. strain pcc 7120 affected in heterocyst development or metabolism. | mutants of anabaena sp. strain pcc 7120 that are incapable of sustained growth with air as the sole source of nitrogen were generated by using tn5-derived transposons. nitrogenase was expressed only in mutants that showed obvious morphological signs of heterocyst differentiation. even under rigorously anaerobic conditions, nitrogenase was not synthesized in filaments that were unable to develop heterocysts. these results suggest that competence to synthesize nitrogenase requires a process that l ... | 1992 | 1328150 |
| characterization of the streptomyces clavuligerus argc gene encoding n-acetylglutamyl-phosphate reductase: expression in streptomyces lividans and effect on clavulanic acid production. | the argc gene of streptomyces clavuligerus encoding n-acetylglutamyl-phosphate reductase (agpr) has been cloned by complementation of argc mutants streptomyces lividans 1674 and escherichia coli xc33. the gene is contained in an open reading frame of 1,023 nucleotides which encodes a protein of 340 amino acids with a deduced molecular mass of 35,224 da. the argc gene is linked to arge, as shown by complementation of arge mutants of e. coli. expression of argc from cloned dna fragments carrying t ... | 1992 | 1339424 |
| identification, genetic analysis and characterization of a sugar-non-specific nuclease from the cyanobacterium anabaena sp. pcc 7120. | a nuclease that could be recovered from the supernatant of cultures, as well as from cell-free extracts, of the cyanobacterium anabaena sp. pcc 7120 was identified as a 29 kda polypeptide by its ability to degrade dna after electrophoresis in dna-containing sds-polyacrylamide gels. some clones of a gene library of strain pcc 7120 established in escherichia coli were found to produce the 29 kda nuclease. the nuca gene encoding this nuclease was subcloned and sequenced. the deduced polypeptide, nu ... | 1992 | 1343821 |
| regulation of anabaena sp. strain pcc 7120 glutamine synthetase activity in a synechocystis sp. strain pcc 6803 derivative strain bearing the anabaena glna gene and a mutated host glna gene. | the glna gene from synechocystis sp. strain pcc 6803 was cloned by hybridization with the glna gene from anabaena sp. strain pcc 7120, and a deletion-insertion mutation of the synechocystis gene was generated in vitro. a strain derived from synechocystis sp. strain pcc 6803 which contained integrated into the chromosome, in addition to its own glna gene, the anabaena glna gene was constructed. from that strain, a synechocystis sp. glna mutant could be obtained by transformation with the inactiva ... | 1992 | 1345914 |
| molecular characterization of the gene encoding glutamine synthetase in the cyanobacterium calothrix sp. pcc 7601. | in order to study the regulation of the synthesis of glutamine synthetase in response to changes in environmental parameters (light and nitrogen sources), we have cloned and sequenced the glna gene from the filamentous cyanobacterium calothrix pcc 7601. this gene consists of 472 codons and encodes a polypeptide of m(r) 52,290 highly homologous to that from anabaena pcc 7120, but more distant from those identified from other procaryotes. the relative abundance of the two glna transcripts (1.6 and ... | 1992 | 1362348 |
| biosynthesis of the tropane-related cyanobacterial toxin anatoxin-a: role of ornithine decarboxylase. | a study was made of the biosynthesis by anabaena flos-aquae of the tropane-related alkaloid anatoxin-a. evidence is presented that the toxin arises from ornithine via putrescine (1,4-diaminobutane) and that ornithine decarboxylase (ec 4.1.1.17) is involved. an ornithine decarboxylase preparation, with optimal activity at ph 8, was obtained from anabaena flos-aquae and partially purified by gel-filtration chromatography on deae-cellulose. one major and one minor peak of enzymic activity were obta ... | 1990 | 1367427 |
| multiple rpod-related genes of cyanobacteria. | genomes of many eubacterial strains have been shown to encode for multiple rpod-related genes. in this report, we describe the identification of the multiple rpod-related genes of cyanobacterial strains. dnas of three cyanobacterial strains, anabaena sp. pcc7120, synechococcus sp. pcc7942, and synechocystis sp. pcc6803, were examined by southern hybridization, using a synthetic probe designed for detecting rpod or rpod-related genes. four or five hybridization signals were found in each dna. fou ... | 1992 | 1368828 |
| quantitative and qualitative dna variations in anabaena azollae strasb. living in azolla filiculoides lam. | heterocysts and vegetative cells of the filamentous nitrogen-fixing anabaena azollae isolated from the apex to the basal leaf cavities of azolla filiculoides were examined by epifluorescent microscope after fluorochrome staining. acridine orange (ao), dapi, and chromomycin fluorochromes were used in order to evidence total dna content and respectively, a + t and g + c bases. measurements of fluorescence intensities were made on photographic prints by the automatic image analysis system quantimet ... | 1992 | 1374307 |
| identification of multiple rna polymerase sigma factor homologs in the cyanobacterium anabaena sp. strain pcc 7120: cloning, expression, and inactivation of the sigb and sigc genes. | the siga gene of anabaena sp. strain pcc 7120, encoding the principal rna polymerase sigma factor, and the complement of the rpod oligonucleotide (k. tanaka, t. shiina, and h. takahashi, science 242:1040-1042, 1988) were used as probes to isolate two genes, sigb and sigc, which encode two putative sigma factors exhibiting high degrees of similarity to siga, to hrda, -b, -c, and -d of streptomyces coelicolor, and to katf of escherichia coli. sigb and sigc code for polypeptides of 332 and 416 amin ... | 1992 | 1385387 |
| influence of chromium on some physiological variables of anabaena doliolum: interaction with metabolic inhibitors. | the impact of 2,4-dinitrophenol and chlorophenyl dimethylurea on atp content, carbon fixation, o2 evolution, nitrogenase activity and cr uptake of anabaena doliolum has been studied. 2,4-dinitrophenol has been found to be more toxic than chlorophenyldimethylurea for all these processes. however, when cr toxicity to above variables was assessed in their presence the interaction was less than additive. an initial (10-15 min) concentration-dependent rapid cr uptake, followed by a slow one, indicate ... | 1992 | 1392466 |
| in vitro activation of dinitrogenase reductase from the cyanobacterium anabaena variabilis (atcc 29413). | nitrogenase of the heterocystous cyanobacterium anabaena variabilis was inactivated in vivo (s. reich, h. almon, and p. böger, fems microbiol. lett. 34:53-56, 1986). partially purified and modified (inactivated) dinitrogenase reductase (fe-protein) of such cells was reactivated by isolated membrane fractions of a. variabilis or of rhodospirillum rubrum, and acetylene reduction was measured. reactivation requires atp, mg2+, and mn2+. the activating principle is localized in the heterocyst and was ... | 1992 | 1400166 |
| isolation of arginine auxotrophs, cloning by mutant complementation, and sequence analysis of the argc gene from the cyanobacterium anabaena species pcc 7120. | arginine auxotrophs of the dinitrogen-fixing cyanobacterium anabaena species strain pcc 7120 were isolated after ultraviolet light mutagenesis and penicillin enrichment. two of these auxotrophs were complemented by a cosmid gene library of the wild-type strain established in escherichia coli that was transferred en masse to the mutants by conjugation. the gene complementing one of those mutants was found to complement an e. coli argc mutant. sequencing analysis of the gene showed that it encodes ... | 1992 | 1406250 |
| growth pattern changes of chlorella vulgaris and anabaena doliolum due to toxicity of dimethoate and endosulfan. | | 1992 | 1421852 |
| antifungal cyclic peptides from the terrestrial blue-green alga anabaena laxa. i. isolation and biological properties. | laxaphycins are responsible for the antifungal and cytotoxic activity of crude ethanolic extracts from the cultured blue-green alga anabaena laxa. these cyclic peptides exhibit an unusual biological synergism when tested for antifungal or cytotoxic effects. the isolation procedure for the peptides, their characterization and biological activities are described here along with experiments demonstrating synergism between the two major laxaphycins. | 1992 | 1429231 |
| antifungal cyclic peptides from the terrestrial blue-green alga anabaena laxa. ii. structures of laxaphycins a, b, d and e. | laxaphycins a and b are the major components in an antifungal mixture of cyclic peptides from the terrestrial blue-green alga anabaena laxa fk-1-2. nmr and ms spectral studies coupled with amino acid analysis indicate that the gross structures of laxaphycins a and b are cyclic (aoc-hse-e-dhb-hyp-hse-phe-leu-ile-ile-leu-gly) where aoc is a 3-aminooctanoic acid residue and cyclic (ala-hleu-gln-n-meile-hasn-thr-pro-leu-thr-ade-val- hleu) where ade is a 3-aminodecanoyl unit, respectively. laxaphycin ... | 1992 | 1429232 |
| semipreparative isolation of individual cyanobacterial heterocyst-type glycolipids by reverse-phase high-performance liquid chromatography. | procedures are described for the quantitative, semi-preparative isolation of individual cyanobacterial heterocyst-type glycolipids (hgs) by reverse-phase hplc (rp-hplc) and the modifications to conventional techniques necessary to prevent significant hg losses during sample preparation. total lipids are obtained from cultures of nitrogen-fixing cyanobacteria by triplicate extraction with 200 packed-cell volumes of chloroform/methanol (1/1, v/v), filtered, and redissolved in chloroform for loadin ... | 1992 | 1443590 |
| identification of arginyl residues involved in the binding of ferredoxin-nadp+ reductase from anabaena sp. pcc 7119 to its substrates. | ferredoxin-nadp+ reductase from the cyanobacterium anabaena sp. pcc 7119 was chemically modified by the alpha-dicarbonyl reagent phenylglyoxal. the studies of the inactivation by this compound, which is specific for arginyl residues, of both the diaphorase and nadph-cytochrome c reductase activities, characteristic of the enzyme, are indicative of the involvement of at least one group of this kind in the binding site of nadp+ and a second one implicated in the interaction with ferredoxin. after ... | 1992 | 1444467 |
| purification and properties of urease from the cyanobacterium anabaena cylindrica. | a purification procedure has been developed by which urease activity in extracts from the cyanobacterium anabaena cylindrica was enriched 500-fold. the procedure involves mgso4 precipitation at 55 degrees c and chromatography on hydroxylapatite and diethylaminoethyl sephadex. its molecular weight was measured by sedimentation equilibrium in an airfuge to be 197,000 +/- 2000 with an estimated subunit molecular weight of 32,000 as determined by polyacrylamide gel electrophoresis. the ph- and tempe ... | 1992 | 1445371 |
| structures of three new homotyrosine-containing microcystins and a new homophenylalanine variant from anabaena sp. strain 66. | a hepatotoxic strain of cyanobacterium anabaena sp. 66 was isolated from a hepatotoxic water bloom sample in lake kiikkara, finland. four cyclic heptapeptide hepatotoxins were isolated and purified by hplc from cultured cells of this organism. the structures of three new homotyrosine (hty) containing toxins, [dha7]microcystin-htyr (dha = dehydroalanine) (1), [d-asp3,dha7]microcystin-htyr (2), and [l-ser7]microcystin-htyr (3), were assigned, based upon amino acid analyses using both a waters pico ... | 1992 | 1446006 |
| a laser flash absorption spectroscopy study of anabaena sp. pcc 7119 flavodoxin photoreduction by photosystem i particles from spinach. | electron transfer from p700 in photosystem i (psi) particles from spinach to anabaena sp. pcc 7119 flavodoxin has been studied using laser flash absorption spectroscopy. a non-linear protein concentration dependence of the rate constants was obtained, suggesting a two-step mechanism involving complex formation (k = 3.6 x 10(7) m-1.s-1) followed by intracomplex electron transfer (k = 270 s-1). the observed rate constants had a biphasic dependence on the concentrations of nacl or mgcl2, with maxim ... | 1992 | 1446742 |
| metal induced inhibition of photosynthesis, photosynthetic electron transport chain and atp content of anabaena doliolum and chlorella vulgaris: interaction with exogenous atp. | this study demonstrates a concentration dependent inhibition of carbon fixation, o2 evolution, photosynthetic electron transport chain and atp content of a. doliolum and c. vulgaris by cu, ni and fe. although the mode of inhibition of photosynthetic electron transport chain of both the algae was similar, ps ii depicted greater sensitivity to the test metals used. the toxicity in both organisms was cu > ni > fe. a. doliolum was, however, more sensitive to cu and ni, and c. vulgaris to fe. toxicit ... | 1992 | 1449660 |
| genetic analysis of photosynthesis in prokaryotes and lower eukaryotes. | | 1992 | 1458026 |
| effects of chemical modification of anabaena flavodoxin and ferredoxin-nadp+ reductase on the kinetics of interprotein electron transfer reactions. | the influence of chemical modification of arginine residues (using phenylglyoxal) in ferredoxin-nadp+ reductase (fnr), and of carboxyl groups (using glycine ethyl ester) in flavodoxin (fld), on the kinetics of electron transfer between fnr and fld, and between ferredoxin (fd) and fnr, was examined using laser flash photolysis methods. all proteins were obtained from the cyanobacterium anabaena pcc7119. reduction by laser-generated 5-deazariboflavin semiquinone of the fad moiety of phenylglyoxal- ... | 1992 | 1459139 |
| presence of an n-terminal presequence in the psai protein of the photosystem i complex in the filamentous cyanobacterium anabaena variabilis atcc 29413. | the psai gene encoding the 5.2 kda protein component (psai) of the photosystem i complex was cloned from the cyanobacterium anabaena 29413. the gene is present in single copy in this cyanobacterial genome. the nucleotide sequence of a 500 bp region of the cloned dna revealed the presence of an open reading frame encoding a 46 amino acid long polypeptide. the n-terminal 11 residues are absent in the mature polypeptide and thus represents the first identified cleavable presequence on the psai prot ... | 1992 | 1463834 |
| purification, characterization and function of dihydrolipoamide dehydrogenase from the cyanobacterium anabaena sp. strain p.c.c. 7119. | a dihydrolipoamide dehydrogenase (dihydrolipoamide: nad+ oxidoreductase, ec 1.8.1.4) (dld) has been found in the soluble fraction of cells of both unicellular (synechococcus sp. strain p.c.c. 6301) and filamentous (calothrix sp. strain p.c.c. 7601 and anabaena sp. strain p.c.c. 7119) cyanobacteria. dld from anabaena sp. was purified 3000-fold to electrophoretic homogeneity. the purified enzyme exhibited a specific activity of 190 units/mg and was characterized as a dimeric fad-containing protein ... | 1992 | 1471997 |
| developmentally regulated gene rearrangements in prokaryotes. | | 1992 | 1482108 |
| two new l-serine variants of microcystins-lr and -rr from anabaena sp. strains 202 a1 and 202 a2. | two new microcystins, [l-ser7]microcystin-lr (1) and [l-ser7]microcystin-rr (2), were isolated from a filamentous fresh water cyanobacterium (blue-green alga), anabaena sp. strain 202 a1, along with the two major toxins, [dha7]microcystin-lr (3) and [dha7]microcystin-rr (4) and their minor components the d-asp variants [d-asp3,dha7]microcystin-lr (5) and [d-asp3,dha7]microcystin-rr (6). anabaena sp. strain 202 a1 also produced another new toxin, whose structure is tentatively proposed as [d-asp3 ... | 1992 | 1485340 |
| two methyl ester derivatives of microcystins, cyclic heptapeptide hepatotoxins, isolated from anabaena flos-aquae strain cya 83/1. | cultured cells of anabaena flos-aquae strain cya 83/1, isolated from lake edlandsvatn, norway, produced two microcystin mono-methyl ester derivatives (1 and 2) at the d-glu unit in addition to microcystin-lr (3), [d-asp3]microcystin-lr (4), microcystin-rr (5), and [d-asp3]microcystin-rr (6). structures of these compounds were assigned based on their amino acid analysis with a waters pico tag hplc system plus fast atom bombardment mass spectrometry (fabms), including tandem fabms, analysis on the ... | 1992 | 1485341 |
| gas vesicles are strengthened by the outer-surface protein, gvpc. | the critical collapse pressure of gas vesicles isolated from anabaena flos-aquae decreased from 0.557 to 0.190 mpa when gvpc, the hydrophilic 22 kda protein present on the outer surface of the gas vesicle, was removed by rising in 6 m urea. recombinant gvpc was purified from inclusion bodies, produced in an e. coli strain containing an expression vector bearing the gene encoding gvpc from a. flos-aquae, and then solubilised in 6 m urea. this recombinant gvpc became bound to gas vesicles that had ... | 1992 | 1510555 |
| isolation and characterization of a variety of microcystins from seven strains of the cyanobacterial genus anabaena. | hepatotoxins (microcystins) from seven freshwater anabaena strains originating from three different finnish lakes and one lake in norway were isolated by high-performance liquid chromatography and characterized by amino acid analysis and fast atom bombardment mass spectrometry. all strains produced three to seven different microcystins. a total of 17 different compounds were isolated, of which 8 were known microcystins. the known compounds identified from six strains were mcyst (microcystin)-lr, ... | 1992 | 1514796 |
| the homologies of gas vesicle proteins. | in addition to gvpa, the main structural protein, an sds-soluble protein has been found in gas vesicles isolated from six different genera of cyanobacteria. n-terminal sequence analysis of the first 30 to 60 residues of the gel-purified proteins showed that they were homologous to gvpc, a protein that strengthens the gas vesicle in anabaena flos-aquae. the proteins from some of the organisms showed rather low homology, however, and this may explain why the genes that encode them have not been fo ... | 1992 | 1527496 |
| differential effect of dimethoate toxicity to anabaena doliolum with change in nutrient status. | | 1992 | 1536992 |
| lysine residues on ferredoxin-nadp+ reductase from anabaena sp. pcc 7119 involved in substrate binding. | ferredoxin-nadp+ reductase from anabaena sp. pcc 7119 is chemically modified by pyridoxal 5'-phosphate. the incorporation of 2 +/- 0.3 mol pyridoxal 5'-phosphate/mol ferredoxin-nadp+ reductase inhibited nadph-cytochrome c reductase activity by up to 95% while 55% of diaphorase activity still remained. considerable protection against inactivation was afforded by ferredoxin. chymotryptic cleavage of the modified enzyme was performed, the peptides were separated by high performance liquid chromatog ... | 1992 | 1544417 |
| crystallization and preliminary analysis of oxidized, recombinant, heterocyst [2fe-2s] ferredoxin from anabaena 7120. | the [2fe-2s] ferredoxin produced in the heterocyst cells of anabaena 7120 plays a key role in nitrogen fixation, where it serves as an electron acceptor from various sources and an electron donor to nitrogenase. crystals of recombinant heterocyst ferredoxin, coded for by the fdx h gene from anabaena 7120 and overproduced in escherichia coli, have been grown from ammonium sulfate solutions and are suitable for high resolution x-ray crystallographic analysis. they belong to the hexagonal space gro ... | 1992 | 1550351 |
| effects of phenoxy acetic herbicides on growth, photosynthesis, and nitrogenase activity in cyanobacteria from rice fields. | the effects of the phenoxy acetic herbicides 2,4-dichlorophenoxy acetic acid (2,4d) and methylchlorophenoxy acetic acid (mcpa) on growth, photosynthesis, and nitrogenase activity of cyanobacteria has been investigated. concentrations ranging from 10(-9) to 10(-3) m did not change significantly the parameters of anabaena uam 202. concentrations higher than 10(-3) m of both herbicides were toxic. the primary toxic action of these herbicides in anabaena uam 202 was on photosynthesis. | 1992 | 1554245 |
| activities of two dissimilar thioredoxins from the cyanobacterium anabaena sp. strain pcc 7120. | thioredoxin is a small redox protein that functions as a reducing agent and modulator of enzyme activity. a gene for an unusual thioredoxin was previously isolated from the cyanobacterium anabaena sp. strain pcc 7120 and cloned and expressed in escherichia coli. however, the protein could not be detected in anabaena cells (j. alam, s. curtis, f. k. gleason, m. gerami-nejad, and j. a. fuchs, j. bacteriol. 171:162-171, 1989). polyclonal antibodies to the atypical thioredoxin were prepared, and the ... | 1992 | 1556078 |
| genes encoding the phycobilisome rod substructure are clustered on the anabaena chromosome: characterization of the phycoerythrocyanin operon. | the phycoerythrocyanin (pec) operon, cloned from anabaena sp. strain pcc 7120, encodes four genes, pecbace, located upstream of the c-phycocyanin (cpc) operon. this pec-cpc cluster includes all the genes for the structural components of the phycobilisome rod. oligonucleotide probes based on the amino-terminal sequence of the phycoerythrocyanin beta subunit were used to clone an 8.0-kbp ecori fragment which was determined, by sequencing, to partially overlap the previously cloned cpc operon. a 5. ... | 1992 | 1556083 |
| nucleotide sequence and expression of the gene for the 9 kda fa/fb component of photosystem i from the cyanobacterium anabaena sp. pcc7120. | the nucleotide sequence of an 813 bp ssp i-hinc ii fragment containing the psac gene from anabaena sp. pcc 7120 is reported. the gene encodes a polypeptide of 81 amino acids, has a single transcript of size approximately 480 nucleotides and a single startpoint of transcription. it is flanked by a ribosome binding site on the 5' end and a potential transcription terminator on the 3' end. comparison of the amino acid sequences of the psac gene product from sixteen organisms shows that cyanobacteri ... | 1992 | 1558954 |
| effects of acephate on n2-fixing cyanobacterium anabaena pcc 7119. | | 1992 | 1568067 |
| phycobilisome structure in the cyanobacteria mastigocladus laminosus and anabaena sp. pcc 7120. | phycobilisomes of the cyanobacteria mastigocladus laminosus and anabaena sp. pcc7120 differ from typical tricylindrical, hemidiscoidal phycobilisomes in three respects. firstly, size comparisons of the core-membrane linker phycobiliproteins (lcm) in different cyanobacteria by sds/page reveal an apparent molecular mass of 120 kda for the lcm of m. laminosus and anabaena sp. pcc7120. this observation suggests that the polypeptides of these species have four linker-repeat domains. secondly, phycobi ... | 1992 | 1577008 |
| structure of the genes encoding the rod-core linker polypeptides of mastigocladus laminosus phycobilisomes and functional aspects of the phycobiliprotein/linker-polypeptide interactions. | the 3' portion of the cpc operon in mastigocladus laminosus encloses the genes 5'-cpcf-cpcg1-cpcg2-cpcg3 3'. the three cpcg genes encode different phycocyanin-associated rod-core linker polypeptides of the phycobilisomes with predicted 279, 247 and 254 amino acids in length. the gene products cpcg show a high similarity at their n-terminal domains (190 amino acids) and an overall identity of 47-53% to one another. each of the three cpcg polypeptides is highly related to one of the four cpcg gene ... | 1992 | 1577010 |
| differentiation of free-living anabaena and nostoc cyanobacteria on the basis of fatty acid composition. | the cellular fatty acids of free-living, nitrogen-fixing cyanobacteria belonging to the genera anabaena and nostoc were analyzed to differentiate the genera. the fatty acid compositions of 10 anabaena strains and 10 nostoc strains that were grown for 12 days on bg-11o medium were determined by gas-liquid chromatography-mass spectroscopy. of the 53 fatty acids detected, 17 were major components; the average level for each of these 17 fatty acids was at least 0.9% of the total fatty acids (in at l ... | 1992 | 1581185 |
| impact of spectral quality on toxicity of iron in anabaena doliolum and chlorella vulgaris. | evidence is presented on the effects of low and high concentrations of iron on growth, nutrient uptake (nh+4 and no3-), photosynthesis (co2-fixation and o2-evolution) and nitrate reductase (nr) activity of a. doliolum and c. vulgaris under monochromatic irradiation. control cultures (not treated with fecl3) showed maximum growth under fluorescent followed by red, yellow, blue and green lights (fluorescent greater than yellow greater than red greater than blue greater than green). the inhibition ... | 1992 | 1586469 |
| identification, characterization and sequence analysis of the gene encoding phosphoenolpyruvate carboxylase in anabaena sp. pcc 7120. | the gene (ppc) encoding phosphoenolpyruvate carboxylase (pepcase) in the cyanobacterium anabaena sp. pcc 7120 has been isolated, characterized and its nucleotide sequence determined. heterologous hybridization using the synechococcus sp. pcc 7942 ppc gene as a probe of an anabaena genomic dna library identified an 8.2 kb hindiii dna fragment that contained a 3.08 kb open reading frame encoding the cyanobacterial pepcase. deletion analysis of the 8.2 kb dna fragment was used to determine sequence ... | 1992 | 1588304 |
| the pata gene product, which contains a region similar to chey of escherichia coli, controls heterocyst pattern formation in the cyanobacterium anabaena 7120. | in anabaena 7120, heterocysts (cells specialized for nitrogen fixation) develop at the ends of filaments and at intervals within each filament. we have isolated a mutant anabaena strain that develops heterocysts mostly at the ends of filaments. this mutant, pat-1, grows poorly under nitrogen-fixing conditions. the wild-type gene that complements the mutation in pat-1, called pata, was cloned and sequenced. the predicted pata protein contains 379 amino acids distributed among three "domains" base ... | 1992 | 1608976 |
| purification and characterization of the photosystem i complex from the filamentous cyanobacterium anabaena variabilis atcc 29413. | a photoactive photosystem i complex has been purified from the filamentous, nitrogen-fixing cyanobacterium anabaena variabilis atcc 29413. cells were broken using glass beads, and the membrane fraction was solubilized with beta-dodecyl maltoside followed by two rounds of fast protein liquid chromatography on anion exchange columns. the polypeptide composition of the isolated complex was determined by sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis and n-terminal amino acid sequenc ... | 1992 | 1618755 |
| stability studies on the cyanobacterial nicotinic alkaloid anatoxin-a. | anatoxin-a (antx-a) is a potent nicotinic cholinergic bicyclic secondary amine produced by some toxigenic strains of anabaena spp. cyanobacteria (ld50 = 0.20-0.25 mg/kg i.p., mouse). studies were undertaken to examine the effects of sunlight, ph, oxygen, and copper and iron, known catalysts of nitrogen oxidation, on the stability of antx-a. photolysis of this extremely potent toxin was demonstrated under conditions resembling those which occur naturally. first-order decay kinetics of antx-a in s ... | 1991 | 1646499 |
| characterization of insertion sequence is892 and related elements from the cyanobacterium anabaena sp. strain pcc 7120. | is892, one of the several insertion sequence (is) elements discovered in anabaena sp. strain pcc 7120 (y. cai and c. p. wolk, j. bacteriol. 172:3138-3145, 1990), is 1,675 bp with 24-bp near-perfect inverted terminal repeats and has two open reading frames (orfs) that could code for proteins of 233 and 137 amino acids. upon insertion into target sites, this is generates an 8-bp directly repeated target duplication. a 32-bp sequence in the region between orf1 and orf2 is similar to the sequence of ... | 1991 | 1653218 |
| characterization of the is895 family of insertion sequences from the cyanobacterium anabaena sp. strain pcc 7120. | a family of repetitive elements from the cyanobacterium anabaena sp. strain pcc 7120 was identified through the proximity of one element to the psbai gene. four members of this seven-member family were isolated and shown to have structures characteristic of bacterial insertion sequences. each element is approximately 1,200 bp in length, is delimited by a 30-bp inverted repeat, and contains two open reading frames in tandem on the same dna strand. the four copies differ from each other by small i ... | 1991 | 1653219 |