Publications

preferred sites on cytochrome c for electron transfer with two positively charged blue copper proteins, anabaena variabilis plastocyanin and stellacyanin.	rate constants for the reactions of horse cytochrome c (e'0 of +260 mv) with the copper proteins anabaena variabilis plastocyanin (e'0 of +360 mv) used as oxidant and stellacyanin (e'0 of +187 mv) used as reductant have been determined at 25 degrees c, ph 7.5 and 7.0, respectively, and an ionic strength of 0.10 m (nacl). these rate constants were also measured with eight different singly substituted 4-carboxy-2,6-dinitrophenyl (cdnp) horse cytochrome c derivatives, modified at lysine-7, -13, -25 ...	1986	3026438
sequence of glutamine synthetase from salmonella typhimurium and implications for the protein structure.	to aid in the interpretation of the 3.5 a resolution electron density map of glutamine synthetase (gs) from salmonella typhimurium, the nucleotide sequence of the gene coding for this enzyme has been determined. the predicted sequence of 468 amino acids (mr = 51,628) has been compared to the sequence and sequence fragments reported by others for gs of anabaena and escherichia coli. the homology between the pairs of sequences is sufficiently strong to suggest that the overall three-dimensional st ...	1986	2879772
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
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
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
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
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
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
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
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
coding sequence of a ferredoxin gene from anabaena variabilis atcc 29413.		1986	3095790
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
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
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
characterization of several tropical strains of anabaena and nostoc: morphological and physiological properties, and plasmid content.	thirty anabaena and nostoc strains isolated from west african soils were characterized for their morphological and physiological properties, and surveyed for plasmids. most strains were found to harbour one to five plasmids whose molecular masses ranged from 1.5 to 120-150 x 10(6) daltons. no relationship between these plasmids and phenotypic properties such as carbon source utilization, antibiotic resistance or cyanophage and toxin production could be established.	1986	3122637
post-translational methylation of asparaginyl residues. identification of beta-71 gamma-n-methylasparagine in allophycocyanin.	a novel post-translationally modified residue, gamma-n-methylasparagine, was detected in the beta subunit of anabaena variabilis allophycocyanin. structure determination was accomplished by isolating a decapeptide, ap-beta (63-72) shown to have the following structure: ser-asp-ile-thr-arg-pro-gly-gly- asn[n-ch3]-homoserine lactone fast atom bombardment-mass spectrometry established that the residue corresponding to position 71 in the protein (delange, r. j., williams, l. c., and glazer, a. n. (1 ...	1986	3782095
isolation and localization of n4-methylasparagine in phycobiliproteins from the cyanobacterium mastigocladus laminosus.	the occurrence of post-translationally methylated asparagine residues in beta ap from anabaena variabilis, synechococcus pcc 6301 and porphyridium cruentum has recently been reported (klotz, a.v., leary, j.a. & glazer, a.n. (1986) j. biol. chem. 261, 15891-15894). we reinvestigated the amino-acid compositions of all phycobiliproteins from mastigocladus laminosus. during total hydrolysis of beta ap, beta 16.2 and beta pc one mol methylamine per mol protein was released. these proteins were chemic ...	1987	3122783
induction of siderophore activity in anabaena spp. and its moderation of copper toxicity.	growth of anabaena sp. strain 7120 (in the absence of chelators or added iron) was inhibited by the addition of 2.1 to 6.5 microm copper and was abolished by copper concentration of 10 microm or higher. when the copper was chelated to schizokinen (the siderophore produced by this organism in response to iron starvation), the toxic effects were eliminated. analysis of culture filtrates showed that the cupric schizokinen remains in the medium, thereby lowering the amount of copper taken up by the ...	1987	2955743
nadh:hydroxypyruvate reductase and nadph:glyoxylate reductase in algae: partial purification and characterization from chlamydomonas reinhardtii.	hydroxypyruvate and glyoxylate reductase activities were measured in extracts from the unicellular green algae, chlamydomonas reinhardtii, chlorella vulgaris, chlorella miniata, and dunaliella tertiolecta. only trace levels of these activities were detectable in the blue-green algae, anabaena variabilis and synechococcus leopoliensis. a nadh-dependent hydroxypyruvate reductase was purified 130-fold from chlamydomonas to a specific activity of 18 mumol nadh oxidized x min-1 x mg protein-1. the ph ...	1987	3545081
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
dl-7-azatryptophan and citrulline metabolism in the cyanobacterium anabaena sp. strain 1f.	an alternative route for the primary assimilation of ammonia proceeds via glutamine synthetase-carbamyl phosphate synthetase and its inherent glutaminase activity in anabaena sp. strain 1f, a marine filamentous, heterocystous cyanobacterium. evidence for the presence of this possible alternative route to glutamate was provided by the use of amino acid analogs as specific enzyme inhibitors, enzymological studies, and radioistopic labeling experiments. the amino acid pool patterns of continuous cu ...	1987	2880834
molecular cloning of a reca-like gene from the cyanobacterium anabaena variabilis.	a reca-like gene isolated from the cyanobacterium anabaena variabilis was cloned and partially characterized. when introduced into escherichia coli reca mutants, the 7.5-kilobase-pair plasmid-borne dna insert restored resistance to methyl methanesulfonate and uv irradiation, as well as recombination proficiency when measured by hfr-mediated conjugation. the cyanobacterial reca gene restored spontaneous but not mitomycin c-induced prophage production. restriction analysis and subcloning yielded a ...	1987	3032896
different recombination site specificity of two developmentally regulated genome rearrangements.	in the absence of a combined nitrogen source, such as ammonia, approximately every tenth vegetative cell along filaments of the cyanobacterium anabaena develops into a heterocyst, a terminally differentiated cell that is morphologically and biochemically specialized for nitrogen fixation. at least two specific dna rearrangements involving the nitrogen-fixation (nif) genes occur during heterocyst differentiation, one within the nifd gene and the other near the nifs gene. the two rearrangements ha ...	1987	3035382
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
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
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
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
subparticles of anabaena phycobilisomes. ii. molecular assembly of allophycocyanin cores in reference to "anchor" protein.	entire phycobilisomes (pbs) and two derived particles, whole allophycocyanin (apc) cores and the far-red-emitting fragment of apc cores (14.5 s apc), all containing the 115-kda polypeptide ("anchor protein"), were compared for the readiness with which the 115-kda protein could be modified chemically, be degraded by chymotrypsin, and react with the anti-115-kda serum. the 115 kda in pbs and the whole apc cores were digested slightly by chymotrypsin and did not react with anti-115-kda igg. in cont ...	1987	3111377
uv-inducible dna repair in the cyanobacteria anabaena spp.	strains of the filamentous cyanobacteria anabaena spp. were capable of very efficient photoreactivation of uv irradiation-induced damage to dna. cells were resistant to several hundred joules of uv irradiation per square meter under conditions that allowed photoreactivation, and they also photoreactivated uv-damaged cyanophage efficiently. reactivation of uv-irradiated cyanophage (weigle reactivation) also occurred; uv irradiation of host cells greatly enhanced the plaque-forming ability of irra ...	1987	3114232
effects of supplements on the bioaccumulation of lead in anabaena spp.		1987	3117141
purification and characterization of rna polymerase from the cyanobacterium anabaena 7120.	a procedure for the purification of rna polymerase from vegetative cells of the filamentous cyanobacterium anabaena 7120 is described. polyethyleneimine precipitation followed by gel filtration and affinity chromatography steps results in greater than 99% purification with 46% yield. the enzyme has a novel core component of mr = 66,000, designated gamma, in addition to the typical prokaryotic beta'beta alpha 2 core enzyme. the sigma subunit has been identified by reconstitution of specific trans ...	1987	3117788
anatoxin-a(s), an anticholinesterase from the cyanobacterium anabaena flos-aquae nrc-525-17.	anatoxin a(s) [antx-a(s)] given intraperitoneally to sprague-dawley rats at different doses (0.1-1.0 mg/kg) caused signs of severe cholinergic overstimulation. assays of rat blood acetylcholinesterase (ache) revealed a dose-dependent inhibition. the in vitro inhibition of electric eel acetylcholinesterase (ache, e.c. 3.1.1.7) and horse serum butyrylcholinesterase (buche, e.c. 3.1.1.8) by antx-a(s) was time- and concentration-dependent. the inhibition of electric eel ache follows first order kine ...	1987	3124299
genes encoding the beta and epsilon subunits of the proton-translocating atpase from anabaena sp. strain pcc 7120.	the genes encoding the beta (atpb) and epsilon (atpe) subunits of the atpase from the cyanobacterium anabaena sp. strain pcc 7120 were cloned, and their sequences were determined. atpb and atpe are each single-copy genes in the anabaena genome. the two genes are separated by a 96-base-pair intergenic spacer and transcribed as a single mrna of 2.3 kilobases that initiates approximately 200 base pairs upstream of the atpb coding region. the predicted translation product of atpb has 81 and 68% amin ...	1987	2878921
relationship between sodium influx and salt tolerance of nitrogen-fixing cyanobacteria.	the relationship between sodium uptake and cyanobacterial salt (nacl) tolerance has been examined in two filamentous, heterocystous, nitrogen-fixing species of anabaena. during diazotrophic growth at neutral ph of the growth medium, anabaena sp. strain l-31, a freshwater strain, showed threefold higher uptake of na than anabaena torulosa, a brackish-water strain, and was considerably less salt tolerant (50% lethal dose of nacl, 55 mm) than the latter (50% lethal dose of nacl, 170 mm). alkaline p ...	1987	16347419
bioconcentration and metabolism of ddt, fenitrothion and chlorpyrifos by the blue-green algae anabaena sp. and aulosira fertilissima.	anabaena and aulosira fertilissima showed a marked ability to accumulate ddt, fenitrothion and chlorpyrifos. although the maximum accumulation of ddt was almost the same in both organisms, there were significant differences in their abilities to accumulate fenitrothion and chlorpyrifos. patterns of uptake of ddt under different treatments were also similar in both anabaena and aulosira, but there were significant differences in the patterns of accumulation of fenitrothion between these two organ ...	1987	15092729
energization and activation of inorganic carbon uptake by light in cyanobacteria.	the requirement of the inorganic carbon (c(i)) transport system for light in cyanobacteria was investigated in anabaena variabilis by the filtering centrifugation technique and in a mutant (e(1)) isolated from anacystis nidulans using a gas exchange system. c(i) transport capability increased with time of preillumination and decreased following darkening. full activity could not be obtained by operating either photosystem ii (psii) or photosystem i alone. 3(3,4 dichlorophenyl)-1,1 dimethylurea s ...	1987	16665418
azolla-anabaena relationship : xiii. fixation of [n]n(2).	the major radioactive products of the fixation of [(13)n]n(2) by azolla caroliniana willd.-anabaena azollae stras. were ammonium, glutamine, and glutamate, plus a small amount of alanine. ammonium accounted for 70 and 32% of the total radioactivity recovered after fixation for 1 and 10 minutes, respectively. the presence of a substantial pool of [(13)n]n(2)-derived (13)nh(4) (+) after longer incubation periods was attributed to the spatial separation between the site of n(2)-fixation (anabaena) ...	1987	16665538
contiguous organization of nitrogenase genes in a heterocystous cyanobacterium.	the organization of the three structural nitrogen fixation (nif) genes that encode nitrogenase (nif k and nif d) and nitrogenase reductase (nif h) have been examined in a number of cyanobacteria. hybridization of anabaena 7120 nif gene probes to restriction endonuclease-digested genomic dna has shown (a) that cyanobacteria incapable of n(2) fixation have no regions of dna with significant homology to the three nif probes, (b) that pseudanabaena sp., a nonheterocystous cyanobacterium, has a conti ...	1987	16665666
sodium requirement for photosynthesis and its relationship with dinitrogen fixation and the external co(2) concentration in cyanobacteria.	cells of anabaena pcc 7119 and of a mutant strain of nostoc muscorum unable to fix dinitrogen, grown at ph 8 and under low co(2) tension (air), showed a reduced capacity for photosynthesis when cultured in the absence of sodium, this inhibition being followed by symptoms of photooxidation, such as chlorosis, oxygen consumption in the light, and decrease of superoxide dismutase activity. the impairment of photosynthesis preceded that of nitrogenase activity, indicating that the requirement for so ...	1987	16665740
factors affecting the photoproduction of ammonia from dinitrogen and water by the cyanobacterium anabaena sp. strain atcc 33047.	synthesis of ammonia from dinitrogen and water by suspensions of anabaena sp. strain atcc 33047 treated with the glutamine synthetase inhibitor l-methionine-d,l-sulfoximine is strictly dependent on light. under otherwise optimal conditions, the yield of ammonia production is influenced by irradiance, as well as by the density, depth, and turbulence of the cell suspension. the interaction among these factors seems to determine the actual amount of light available to each single cell or filament i ...	1987	18576487
aluminum effects on uptake and metabolism of phosphorus by the cyanobacterium anabaena cylindrica.	aluminum severely affects the growth of the cyanobacterium anabaena cylindrica and induces symptoms indicating phosphorus starvation. preor post-treating the cells with high (90 micromolar) phosphorus reduces the toxicity of aluminum compared to cells receiving a lower orthophosphate concentration. in this study aluminum (ranging from 9 to 36 micromolar) and phosphorus concentrations were chosen so that the precipitation of insoluble aipo(4) never exceeded 10% of the total phosphate concentratio ...	1988	16665849
light-induced proton release by the cyanobacterium anabaena variabilis: dependence on co(2) and na.	light-induced acidification by the cyanobacterium anabaena variabilis is biphasic (a fast phase i and slow phase ii) and shown to be sodium-dependent with an optimum concentration of 40 to 60 millimolar na(+). cells grown under low co(2) concentrations at ph 9 (i.e. mainly hco(3) (-) present in the medium) exhibited the slow phase ii of proton efflux only, while cells grown under low co(2) concentrations at ph 6.3 (i.e. co(2) and hco(3) (-) present) exhibited both phases. light-induced proton re ...	1988	16665985
boron protection for o(2) diffusion in heterocysts of anabaena sp. pcc 7119.	the effect of boron on nitrogenase activity has been studied. when cells were dependent on n(2) fixation, the lack of boron inhibited nitrogenase activity. however, under anaerobic conditions or in the presence of na-dithionite this effect was not observed. nitrogenase synthesis was not affected by boron deficiency. similarly, the heterocyst number was not altered. examination of boron-deficient cultures showed, however, some dramatic changes in heterocyst morphology. the increased activity of t ...	1988	16666224
uptake of dieldrin, dimethoate and permethrin by cyanobacteria, anabaena sp. and aulosira fertilissima.	blue-green algae showed a poor ability to pick up and concentrate dieldrin and dimethoate. however, the uptake and bioconcentration factor for permethrin was very high. the uptake of dieldrin by anabaena and aulosira ranged from 5.1 to 73.2 and 5.5 to 17.4 microg g(-1) (ppm), respectively. the uptake of permethrin was from 9.0 to 249.7 and 4.6 to 1422.5 microg g(-1) by anabaena and aulosira, respectively. the highest bioconcentration factors for permethrin in anabaena and aulosira were 813 and 2 ...	1988	15092535
interaction of endosulfan and malathion with blue-green algae anabaena and aulosira fertilissima.	the growth of anabaena and aulosira fertilissima was adversely affected by endosulfan even at 1 microg ml(-1). the inhibition was significantly above 50% at 20 microg ml(-1) throughout the incubation. anabaena survived up to 500 microg ml(-1) of malathion, but was completely bleached in the presence of 50 microg ml(-1) of endosulfan. aulosira was more sensitive to malathion than anabaena and recovered to control levels only at 10 microg ml(-1). the morphology and hetercyst frequency were not alt ...	1988	15092614
isolation and complementation of mutants of anabaena sp. strain pcc 7120 unable to grow aerobically on dinitrogen.	mutants of anabaena sp. strain pcc 7120 unable to grow aerobically on dinitrogen were isolated by mutagenesis with uv irradiation, followed by a period of incubation in yellow light and then by penicillin enrichment. a cosmid vector, prl25c, containing replicons functional in escherichia coli and in anabaena species was constructed. dna from wild-type anabaena sp. strain pcc 7120 was partially digested with sau3ai, and size-fractionated fragments about 40 kilobases (kb) in length were ligated in ...	1988	2830231
restriction analysis and quantitative estimation of methylated bases of filamentous and unicellular cyanobacterial dnas.	the dnas of strains of three cyanobacterial genera (anabaena, plectonema, and synechococcus) were found to be partially or fully resistant to many restriction endonucleases. this could be due to the absence of specific sequences or to modifications, rendering given sequences resistant to cleavage. the latter explanation is substantiated by the content of n6-methyladenine and 5-methylcytosine in these genomes, which is high in comparison with that in other bacterial genomes. dcm- and dam-like met ...	1988	2832390
the principal hydrogen donor for the herpes simplex virus type 1-encoded ribonucleotide reductase in infected cells is a cellular thioredoxin.	in this study herpes simplex virus type 1-encoded ribonucleotide reductase was shown to be able to utilize thioredoxin purified from the cyanobacterium anabaena variabilis as a hydrogen donor for the enzyme. an assay has been developed to search for proteins which can function as a hydrogen donor for the viral ribonucleotide reductase. a protein has been identified and purified to homogeneity from infected cell extracts by a combination of fast protein liquid chromatography and gel filtration. t ...	1988	2832522
an analysis of restriction endonuclease sites in cyanophages infecting the heterocystous cyanobacteria anabaena and nostoc.	an analysis of restriction endonuclease cleavage of dna isolated from cyanophages that infect anabaena and nostoc species of cyanobacteria has provided evidence for counter-selection of restriction endonuclease sites. these include sites containing subsequences which are methylated by host (anabaena pcc 7120) methylase(s) akin to the dam and dcm enzymes of escherichia coli. other sites which are counter-selected have no common sequence structure. the latter include those of the endogenous restri ...	1988	2832536
organization of the nif genes in cyanobacteria in symbiotic association with azolla and anthoceros.	the sizes of endonuclease digestion fragments of dna from cyanobacteria in symbiotic association with azolla caroliniana or anthoceros punctatus, or in free-living culture, were compared by southern hybridization using cloned nitrogenase (nif) genes from anabaena sp. pcc 7120 as probes. the restriction fragment pattern produced by cyanobacteria isolated from a. caroliniana by culture through symbiotic association with anthoceros differed from that of the major symbiotic cyanobacterium freshly se ...	1988	2841912
bacterial-type ferredoxin genes in the nitrogen fixation regions of the cyanobacterium anabaena sp. strain pcc 7120 and rhizobium meliloti.	the nucleotide sequence of a region located downstream of the nifb gene, both in the cyanobacterium anabaena sp. strain pcc 7120 and in rhizobium meliloti, has been determined. this region contains a gene (fdxn) whose predicted polypeptide product strongly resembles typical bacterial ferredoxins. cyanobacteria have not previously been shown to contain bacterial-type ferredoxins. the presence of this gene suggests that nitrogen-fixing cyanobacteria have at least four distinct ferredoxins.	1988	2842320
characterization of two early promoters of cyanophage n-1.	restriction fragments of cyanophage n-1 dna, containing genes transcribed early in infection of anabaena, were identified by hybridization with rna prepared from infected cells. two of these fragments were isolated by binding to anabaena rna polymerase on filters and were subsequently cloned. the start sites for transcription by anabaena rna polymerase were determined by run-off assays. the sequences of the two promoter regions thus localized were similar to each other in the -35 and -10 regions ...	1988	2847412
isolation and restriction analysis of dna from heterocysts and vegetative cells of cyanobacteria.	a procedure was developed for the isolation of heterocysts from cyanobacterial filaments without recourse to mechanical disruption of the vegetative cells. dna was then extracted from purified heterocysts by heating with 2% (w/v) sds at 70 degrees c for 10 min. following purification, this dna was used for treatment with a range of restriction endonucleases and the results compared with dna isolated from vegetative cells. both heterocyst and vegetative dnas from anabaena pcc 7120 and anabaena ca ...	1988	2855526
structure and regulation of genes encoding phycocyanin and allophycocyanin from anabaena variabilis atcc 29413.	gene clones encoding phycocyanin and allophycocyanin were isolated from an anabaena variabilis atcc 29413-charon 30 library by using the phycocyanin (cpc) genes of agmenellum quadruplicatum and the allophycocyanin (apc) genes of cyanophora paradoxa as heterologous probes. the a. variabilis cpca and cpcb genes occur together in the genome, as do the apca and apcb genes; the two sets of genes are not closely linked, however. the cpc and apc genes appear to be present in only one copy per genome. d ...	1988	2450871
ferredoxin-nadp+ oxidoreductase is the respiratory nadph dehydrogenase of the cyanobacterium anabaena variabilis.	the nadph dehydrogenase of the cyanobacterium anabaena variabilis was solubilized, purified, and characterized. activity staining after nondenaturing polyacrylamide gel electrophoresis, kinetics, and immunological characterization led to the conclusion that only one thylakoid-associated nadph dehydrogenase exists in anabaena, identical with ferredoxin-nadp+ oxidoreductase (fnr). after sodium dodecyl sulfate-polyacrylamide gel electrophoresis an intense band at 34 kda and a weak band at 52 kda we ...	1988	2461678
molecular cloning and nucleotide sequence analysis of the gene coding for heterocyst ferredoxin from the cyanobacterium anabaena sp. strain pcc 7120.	in heterocysts of the filamentous cyanobacterium anabaena 7120 a specific [2fe-2s] ferredoxin is synthesized, serving as immediate electron donor to nitrogenase. the structural gene for this heterocyst ferredoxin, fdxh, was isolated from a recombinant lambda library, using an oligonucleotide probe derived from a unique segment of the n-terminal amino acid sequence of the purified protein. the sequence of the entire fdxh coding region was determined including 3' and 5' flanking sequences. assumin ...	1988	2467184
purification and properties of ferredoxin-nadp+ oxidoreductase from the nitrogen-fixing cyanobacteria anabaena variabilis.	the isolation and characterization of ferredoxin-nadp+ -oxidoreductase from anabaena variabilis, a nitrogen-fixing, filamentous cyanobacterium, is described. purified enzyme was obtained in four steps with a 55% yield and 300-fold purification utilizing chromatographic separations on deae-cellulose and cibacron blue-sepharose columns. the enzyme is quite similar but not identical to the spinach enzyme as judged by isoelectric focusing, molecular weight determination, and amino acid composition. ...	1988	3124746
phosphate transport and arsenate resistance in the cyanobacterium anabaena variabilis.	cells of the cyanobacterium anabaena variabilis starved for phosphate for 3 days took up phosphate at about 100 times the rate of unstarved cells. kinetic data suggested that a new transport system had been induced by starvation for phosphate. the inducible phosphate transport system was quickly repressed by addition of pi. phosphate-starved cells were more sensitive to the toxic effects of arsenate than were unstarved cells, but phosphate could alleviate some of the toxicity. arsenate was a non ...	1988	3125150
gtp-binding proteins in a cyanobacterium anabaena cylindrica.	gtp-binding proteins were detected in a crude extract containing membrane components of anabaena cylindrica. the crude extract was treated with 1% lubrol px and was fractionated by gel filtration. the binding of [35s]gtp gamma s to gtp-binding proteins was prevented in the presence of 0.1 mm gtp and in the presence of 0.1 mm atp. six fractions of these gtp-binding proteins, tentatively designated ga1 to ga6, were adp-ribosylated by pertussis toxin. ga3, ga4 and ga5 had km values of 10, 60 and 7 ...	1988	3126734
flavodoxin from anabaena 7120: uniform nitrogen-15 enrichment and hydrogen-1, nitrogen-15, and phosphorus-31 nmr investigations of the flavin mononucleotide binding site in the reduced and oxidized states.	interactions between flavin mononucleotide (fmn) and apoprotein have been investigated in the reduced and oxidized states of the flavodoxin isolated from anabaena 7120 (mr approximately 21,000). 1h, 15n, and 31p nmr have been used to characterize the fmn-protein interactions in both redox states. these are compared with those seen in other flavodoxins. uniformly enriched [15n]flavodoxin (greater than 95% isotopic purity) was isolated from anabaena 7120 grown on k15no3 as the sole nitrogen source ...	1988	3126808
purification and partial characterization of a calcium-stimulated protease from the cyanobacterium, anabaena variabilis.	a calcium-stimulated protease was purified to apparent homogeneity from the heterocyst-forming cyanobacterium anabaena variabilis atcc 29413. as judged from experiments with inhibitors and chromogenic peptide substrates, the enzyme is a serine protease with a substrate specificity like trypsin. its apparent relative molecular mass is 52,000. calcium depletion inhibits the enzymic activity by 92%. half-maximal activity requires about 0.5 microm free ca2+. the enzyme binds to a hydrophobic column ...	1988	3127208
molecular characterization and evolution of sequences encoding light-harvesting components in the chromatically adapting cyanobacterium fremyella diplosiphon.	the major light-harvesting complex in eukaryotic red algae and prokaryotic cyanobacteria is the phycobilisome, a water-soluble complex located on the outer surface of the photosynthetic membranes and composed of both pigmented phycobiliproteins (85%) and non-pigmented linker (15%) polypeptides. the phycobiliproteins are encoded by a gene family and exhibit varying degrees of sequence homology (25 to 55%). some cyanobacteria can maximize the absorption of prevalent wavelengths of light by adjusti ...	1988	3127591
protein carbon-13 spin systems by a single two-dimensional nuclear magnetic resonance experiment.	by applying a two-dimensional double-quantum carbon-13 nuclear magnetic resonance experiment to a protein uniformly enriched to 26 percent carbon-13, networks of directly bonded carbon atoms were identified by virtue of their one-bond spin-spin couplings and were classified by amino acid type according to their particular single- and double-quantum chemical shift patterns. spin systems of 75 of the 98 amino acid residues in a protein, oxidized anabaena 7120 ferredoxin (molecular weight 11,000), ...	1988	3129784
characterization of escherichia coli-anabaena sp. hybrid thioredoxins.	thioredoxin is a small redox protein with an active-site disulfide/dithiol. the protein from escherichia coli has been well characterized. the genes encoding thioredoxin in e. coli and in the filamentous cyanobacterium anabaena pcc 7119 have been cloned and sequenced. anabaena thioredoxin exhibits 50% amino acid identity with the e. coli protein and interacts with e. coli enzymes. the genes encoding anabaena and e. coli thioredoxin were fused via a common restriction site in the nucleotide seque ...	1988	3130096
identification of the region of cyanobacterial plasmid pdu1 necessary for replication in anabaena sp. strain m-131.	shuttle vectors based on plasmid pdu1 from nostoc sp. strain pcc7524 are able to replicate both in escherichia coli and in strains of anabaena and nostoc spp. derivatives partially deleted in the pdu1 portion were tested for their ability to replicate in anabaena sp. strain m-131. plasmid prl6he containing a 1.75-kb hindiii-scai fragment of pdu1 replicated stably in that cyanobacterium and also in anabaena sp. strain pcc7120. plasmid prl6hc, containing an even smaller hpai-scai fragment (1.3 kb) ...	1988	3131190
anticholinesterase poisonings in dogs from a cyanobacterial (blue-green algae) bloom dominated by anabaena flos-aquae.	cyanobacteria (blue-green algae) implicated in the deaths of 9 dogs at richmond lake, sd, on aug 26, 1985, were analyzed. the dominant cyanobacterial species from the water sample was anabaena flos-aquae. the lyophilized bloom material or the high-performance liquid chromatography purified toxin peak, when administered to mice ip, induced clinical signs of salivation, lacrimation, urinary incontinence, defecation, convulsion, fasciculation, and respiratory arrest. further comparison of the semip ...	1988	3132068
analysis of anatoxin-a by gc/ecd.	anatoxin-a (antx-a), a potent cholinergic alkaloid produced by some toxigenic strains of the cyanobacterium anabaena flos-aquae, has been responsible for death of livestock, pets, and wildlife. an increase in the frequency of cyanobacterial blooms in fresh waters of temperate north america has produced a concomitant increase in the threat posed by toxic strains of some of these microorganisms. presently, a mouse bioassay is the general procedure used for testing the toxicity of a bloom-approxima ...	1988	3133523
rna polymerase subunit homology among cyanobacteria, other eubacteria and archaebacteria.	rna polymerase purified from vegetative cells of the cyanobacterium anabaena sp. strain pcc 7120 contains a dissociable sigma factor and a core of five subunits: the beta', beta, and two alpha subunits characteristic of all eubacteria and an additional 66,000-molecular-weight polypeptide called gamma. fifteen of fifteen strains of unicellular and filamentous cyanobacteria tested contained a serologically related gamma protein. antiserum to gamma reacted with escherichia coli beta' and the a subu ...	1988	3137214
[expression of the nif and ntr genes of klebsiella pneumoniae in rhodobacter sphaeroides cells].	the genes glna, ntr, nif or their promoters from klebsiella pneumoniae cloned on the vectors, based on the plasmid rsf1010, were introduced into rhodobacter sphaeroides cells. it was found that k. pneumoniae genes glna, nifb, nife, nifl and nifh are not expressed in r. sphaeroides. neither was the glna gene from cyanobacterium anabaena 7120 expressed in r. sphaeroides. no functional activity of k. pneumoniae product of ntra gene which is expressed from its own promoter, and the product of the ge ...	1988	3139488
toxicity to mice and sheep of a bloom of the cyanobacterium (blue-green alga) anabaena circinalis.	a bloom of anabaena circinalis shown to be lethal to mice (i.p. ld50 17.0 +/- 0.6 mg/kg) was tested for lethal potency when given orally to mice and intraruminally and intraperitoneally to sheep. the lethal oral dose in mice was at least 170 times the parenteral dose. the bloom was lethal when given i.p. to sheep but lethality was not observed when given intraruminally in doses up to 1710 mg/kg, equivalent to drinking 8.5 litres of thick algal bloom, a volume far in excess of that likely to be c ...	1988	3140424
deletion of a 55-kilobase-pair dna element from the chromosome during heterocyst differentiation of anabaena sp. strain pcc 7120.	the filamentous cyanobacterium anabaena sp. strain pcc 7120 produces terminally differentiated heterocysts in response to a lack of combined nitrogen. heterocysts are found approximately every 10th cell along the filament and are morphologically and biochemically specialized for nitrogen fixation. at least two dna rearrangements occur during heterocyst differentiation in anabaena sp. strain pcc 7120, both the result of developmentally regulated site-specific recombination. the first is an 11-kil ...	1988	3141375
the protein encoded by gvpc is a minor component of gas vesicles isolated from the cyanobacteria anabaena flos-aquae and microcystis sp.	the proteins present in gas vesicles of the cyanobacteria anabaena flos-aquae and microcystis sp. were separated by sds-polyacrylamide gel electrophoresis. each contained a protein of mr 22k whose n-terminal amino acid sequences showed homology with that of the calothrix sp. pcc 7601 gvpc gene product. the gvpc gene from a. flos-aquae was cloned and sequenced. the derived amino acid sequence for the gene product indicated a protein, gvpc, of 193 residues and mr 21985 containing five highly conse ...	1988	3141741
acyl-acyl-carrier protein: lysomonogalactosyldiacylglycerol acyltransferase from the cyanobacterium anabaena variabilis.	membranes isolated from the cyanobacterium, anabaena variabilis, and washed free of soluble endogenous constituents, were capable of catalyzing the direct transfer of the acyl group from acyl-acyl-carrier protein to an endogenous lysomonogalactosyldiacylglycerol to form monogalactosyldiacylglycerol. other glycolipids including monoglucosyldiacylglycerol and digalactosyldiacylglycerol were not products of this reaction. the transfer was not dependent on any added cofactors. palmitoyl-, stearoyl- ...	1988	3143419
effect of ammonium nitrate on the heterocyst differentiation and nitrogen fixing activity of anabaena ha 101.	heterocysts were able to be induced while the blue-green alga anabaena ha 101 were grown in a medium free from ammonium nitrate, but the heterocyst formation was inhibited while the anabaena were grown in medium containing 5 mm ammonium nitrate. heterocysts which had already formed were enhanced to senescence by the ammonium nitrate. heterocyst transformation from certain vegetative cells into adult heterocysts accompanied with protein synthesis. a maximal level of protein synthesis as well as t ...	1988	3143523
genome rearrangement and nitrogen fixation in anabaena blocked by inactivation of xisa gene.	two genome rearrangements involving 11- and 55-kilobase dna elements occur during the terminal differentiation of an anabaena photosynthetic vegetative cell into a nitrogen-fixing heterocyst. the xisa gene, located on the nifd 11-kilobase dna element, was inactivated by recombination between the chromosome and a copy of the xisa gene that was mutated by inserting an antibiotic gene cassette. site-directed inactivation of the anabaena xisa gene blocked rearrangement of the 11-kilobase element and ...	1988	3144039
effect of assam crude on photosynthesis and associated electron transport system in anabaena doliolum.		1988	3148341
conservation of nif sequences in frankia.	southern blots of frankia total dnas were hybridized with nifhdk probes from rhizobium meliloti, klebsiella pneumoniae and frankia strain arl3. differences between strains were noted in the size of the hybridizing restriction fragments. these differences were more pronounced among elaeagnus-compatible strains than among alnus- or casuarina-compatible strains. gene banks constructed for frankia strains eun1f, hrn18a, ced and acon24d were used to isolate nif-hybridizing restriction fragments for s ...	1988	3185502
comparison of effects of anatoxin-a(s) and paraoxon, physostigmine and pyridostigmine on mouse brain cholinesterase activity.	anatoxin-a(s), an alkaloid neurotoxin from the freshwater cyanobacterium, anabaena flos-aquae nrc-525-17, was compared to paraoxon, physostigmine and pyridostigmine for effects on brain cholinesterase after i.p. injection into balb/c mice. the duration of clinical signs in mice injected with anatoxin-a(s) persisted longer than in mice given the carbamates and was comparable with that of paraoxon. anatoxin-a(s) did not inhibit brain cholinesterase activity suggesting that this toxin is unable to ...	1988	3188065
genes encoding the alpha, gamma, delta, and four f0 subunits of atp synthase constitute an operon in the cyanobacterium anabaena sp. strain pcc 7120.	a cluster of genes encoding subunits of atp synthase of anabaena sp. strain pcc 7120 was cloned, and the nucleotide sequences of the genes were determined. this cluster, denoted atp1, consists of four f0 genes and three f1 genes encoding the subunits a (atpi), c (atph), b' (atpg), b (atpf), delta (atpd), alpha (apta), and gamma (atpc) in that order. closely linked upstream of the atp synthase subunit genes is an open reading frame denoted gene 1, which is equivalent to the unci gene of escherich ...	1988	2900236
glutamine synthetase specific activity and protein concentration in symbiotic anabaena associated with azolla caroliniana.	glutamine synthetase (gs) is the primary nh4+ assimilating enzyme of cyanobacteria. the specific activities and cellular protein concentration of gs in symbiotic cyanobacteria associated with the water fern azolla caroliniana were determined and compared to free-living cultures of nostoc sp. strain 7801, a strain originally isolated from symbiotic association with the bryophyte anthoceros punctatus. both the in vitro specific activity and concentration of gs in symbiotic cyanobacteria separated ...	1988	2902827
glutamine synthetase from a cyanobacterium, phormidium lapideum: purification, characterization, and comparison with other cyanobacterial enzymes.	glutamine synthetase has been purified to homogeneity from cell extracts of a non-n2-fixing filamentous cyanobacterium, phormidium lapideum. the subunit molecular weight of the enzyme was determined as about 59,000 by sodium dodecyl sulfate gel electrophoresis. electron micrographs of the phormidium enzyme revealed a two-layered structure of regular hexagons (12 subunits per molecule), which markedly resembles the three-dimensional polypeptide backbone structure of the salmonella typhimurium glu ...	1988	2907514
regulation of nitrogenase gene expression in anaerobic cultures of anabaena variabilis.	derepression of nitrogenase gene expression was studied at the mrna and enzyme activity levels in anaerobic cultures of anabaena variabilis 29413. cells, previously grown with ammonium chloride, were incubated in the absence of fixed nitrogen compounds under an ar atmosphere with dichlorophenyldimethyl-urea present to inhibit oxygen evolution. the appearance of nitrogenase mrna (measured by dot blot hybridization analysis) and nitrogenase activity (measured as acetylene-reducing activity) was fo ...	1988	3123456
effect of nitrogenous compounds on nitrogenase gene expression in anaerobic cultures of anabaena variabilis.	the effects of several organic and inorganic nitrogen compounds on nitrogenase mrna and enzyme activity levels were examined in anaerobic cultures of anabaena variabilis 29413. even low concentrations of exogenous ammonia (20 microm) prevented nitrogenase gene expression. nitrate, in contrast, had little effect, even at very high concentrations. neither compound had a significant direct effect on existing enzyme activity. the amino acids glutamine and glutamate did not repress nif gene expressio ...	1988	3123457
isolation, sequence and transcription of the gene encoding the photosystem ii chlorophyll-binding protein, cp-47, in the cyanobacterium anabaena 7120.	the psbb gene from the cyanobacterium anabaena 7120 was cloned and its nucleotide sequence determined. this gene codes for the photosystem ii chlorophyll-binding protein cp-47. we identified an open reading frame of 1527 bases that can code for a polypeptide with a predicted molecular weight of 56,254. expression of the psbb gene in anabaena 7120 results in two transcripts that begin 302 or 238 bp upstream of the open reading frame and both end 288 bp downstream following a 21 bp inverted repeat ...	1989	2485088
purification and properties of soluble hydrogenase from the cyanobacterium anabaena cylindrica.	two soluble hydrogenase activities were separable from cell extracts of the cyanobacterium anabaena cylindrica, one detectable by the tritium exchange assay, the other having a relatively low tritium exchange activity but catalyzing methyl viologen-dependent hydrogen formation. their molecular weights, by gel filtration chromatography, were 42,000 and 100,000, respectively. the two hydrogenase activities were differentially inhibited. the methyl viologen-dependent activity has been purified to h ...	1989	2492182
isolation, sequence, and expression in escherichia coli of an unusual thioredoxin gene from the cyanobacterium anabaena sp. strain pcc 7120.	two sequences with homology to a thioredoxin oligonucleotide probe were detected by southern blot analysis of anabaena sp. strain pcc 7120 genomic dna. one of the sequences was shown to code for a protein with 37% amino acid identity to thioredoxins from escherichia coli and anabaena sp. strain pcc 7119. this is in contrast to the usual 50% homology observed among most procaryotic thioredoxins. one gene was identified in a library and was subcloned into a puc vector and used to transform e. coli ...	1989	2492494
salinity-stress-induced proteins in two nitrogen-fixing anabaena strains differentially tolerant to salt.	salinity altered the protein synthesis patterns in two cyanobacterial strains: anabaena torulosa, a salt-tolerant brackish water strain, and anabaena sp. strain l-31, a salt-sensitive freshwater strain. the cyanobacterial response to salinity was very rapid, varied with time, and was found to be correlated with the external salt (nacl) concentration during stress. salinity induced three prominent types of modification. first, the synthesis of several proteins was inhibited, especially in the sal ...	1989	2492516
thioredoxin is essential for photosynthetic growth. the thioredoxin m gene of anacystis nidulans.	we have taken advantage of the transformation properties of the cyanobacterium anacystis nidulans r2 to investigate the importance of thioredoxin for photosynthetic growth. the gene encoding thioredoxin m, designated trxm, was cloned from a. nidulans using a synthetic oligonucleotide probe. based on the nucleotide sequence, thioredoxin m of a. nidulans is composed of 107 amino acids and shares 84, 48, and 48% sequence identity with thioredoxins from anabaena, spinach, and escherichia coli, respe ...	1989	2492995
changes in gene expression during nitrogen starvation in anabaena variabilis atcc 29413.	when the filamentous, nitrogen-fixing cyanobacterium anabaena variabilis atcc 29413 was subjected to nitrogen starvation under aerobic conditions, a complex series of events was initiated which resulted in heterocyst formation and derepression of the ability to fix dinitrogen. using dna-rna hybridization techniques, we monitored the expression of several genes during nitrogen starvation and correlated changes in the mrna levels with changes in enzyme activity, protein levels, and morphology. nit ...	1989	2493442
low-temperature effects on cyanobacterial membranes.	the effect of change in ambient temperature on fatty acid unsaturation has been studied in the cyanobacterium anabaena variabilis. when cells isothermally grown at 22 degrees c are compared with those grown at 38 degrees c, the relative content of oleic acid decreases and that of linolenic acid increases in all of the lipid classes. after a temperature shift from 38 to 22 degrees c, palmitic acid is rapidly desaturated in monogalactocyldiacylglycerol, but in no other lipids, and oleic acid is sl ...	1989	2496118
toxicity of three herbicides to some nitrogen-fixing cyanobacteria.	the effects of some common rice field herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-d), machete, and saturn, on the paddy field nitrogen-fixing cyanobacteria nostoc linckia, nostoc calcicola, nostoc sp., and anabaena doliolum were studied. these cyanobacteria were found to be more tolerant to 2,4-d (lethal doses 1500-2000 micrograms/ml) than to machete and saturn (lethal doses 6-8 micrograms/ml). the effects of these three herbicides on some physiological processes of n. linckia were s ...	1989	2500323
sequence of the flavodoxin gene from anabaena variabilis 7120.		1989	2500643
the gene for the precursor of plastocyanin from the cyanobacterium anabaena sp. pcc 7937: isolation, sequence and regulation.	the gene encoding plastocyanin (pete1) from anabaena sp. pcc 7937 was isolated using two sets of mixed oligonucleotide hybridization probes derived from conserved regions in the protein. plastocyanin is encoded as a preprotein of 139 amino acids. the amino-terminal extension of 34 residues has all the characteristics of a signal peptide and is probably involved in translocation of preplastocyanin over the thylakoid membrane. the level of the pete1 mrna, a single transcript of about 740 bases, wa ...	1989	2501629
blue-green algae (anabaena spiroides) toxicosis in pigs.	toxicosis caused by anabaena spiroides was diagnosed in 7 of 26 finishing hogs in a farrow-to-finish operation in kentucky. several sick pigs in the herd had the following clinical signs: vomiting, dull appearance, lethargy, anorexia, muscle tremors, frothing at the mouth, coughing, sneezing, dyspnea, and bloody diarrhea. of the 7 dead pigs, 2 were necropsied. tissue speciments and stomach contents were obtained for microscopic, microbiologic, and toxicologic evaluations. in addition, vomitus fr ...	1989	2502512
excision of an 11-kilobase-pair dna element from within the nifd gene in anabaena variabilis heterocysts.	the 3' region of the anabaena variabilis nifd gene contains an 11-kilobase-pair element which is excised from the chromosome during heterocyst differentiation. we have sequenced the recombination sites which border the element in vegetative cells and the rearranged heterocyst sequences. in vegetative cells, the element was flanked by 11-base-pair direct repeats which were identical to the repeats present at the ends of the nifd element in anabaena sp. strain pcc 7120 (anabaena strain 7120). alth ...	1989	2502534
primary structure, functional organization and expression of nitrogenase structural genes of the thermophilic archaebacterium methanococcus thermolithotrophicus.	two regions of homology to anabaena nifh (nitrogenase fe protein) were detected in the total dna of the thermophilic nitrogen-fixing archaebacterium methanococcus thermolithotrophicus. a 2.8 kb hindiii fragment carrying one of these regions was previously cloned and shown to contain a nifh gene (souillard et al., 1988) now referred to as orfnifh2. a 3.4 kb psti fragment and an overlapping 3.8 kb bglii fragment, containing the second region of homology, were cloned, and a dna region of 4073 bp wa ...	1989	2503679
comparative analysis of proteins induced by heat shock, salinity, and osmotic stress in the nitrogen-fixing cyanobacterium anabaena sp. strain l-31.	heat, salinity, or osmotic stress influenced protein synthesis in nitrogen-fixing anabaena sp. strain l-31. salinity and osmotic stresses were identical and specifically induced 15 polypeptides. four polypeptides were unique to heat shock, and four other polypeptides were induced under every stress. the results demonstrate a commonality and a stress specificity of protein synthesis regulation.	1989	2504700