| hepatocellular uptake of 3h-dihydromicrocystin-lr, a cyclic peptide toxin. | the cellular uptake of microcystin-lr, a cyclic heptapeptide hepatotoxin from the cyanobacterium microcystis aeruginosa, was studied by means of a radiolabelled derivative of the toxin. 3h-dihydromicrocystin-lr. the uptake of 3h-dihydromicrocystin-lr was shown to be specific for freshly isolated rat hepatocytes whereas the uptake in the human hepatocarcinoma cell line hep g2 as well as the mouse fibroblast cell line nih-3t3, and the human neuroblastoma cell line sh-sy5y, was negligible. by means ... | 1990 | 2369577 |
| estimation of gene expression in heterocysts of anabaena variabilis by using dna-rna hybridization. | in the filamentous cyanobacterium anabaena variabilis, specialized cells called heterocysts occur in a regular pattern along the filament and are the sites of nitrogen fixation. we used two different types of dna-excess rna hybridization techniques to estimate the number of genes expressed in recently differentiated, mature heterocysts. in the first, rna and dna were incubated in a phosphate buffer at 60 degrees c, and the hybrids were separated from the unhybridized material by hydroxylapatite ... | 1986 | 2427500 |
| polysome turnover in immobilized cells of nostoc commune (cyanobacteria) exposed to water stress. | water stress induced changes in the polysome content of immobilized cells of the desiccation-tolerant cyanobacterium nostoc commune utex 584. cells maintained an intact protein synthesis complex during 2 h of drying at -99.5 mpa. polysomes were not recovered from cells subjected to extended periods of desiccation. | 1986 | 2430937 |
| isolation and sequence of the gene for ferredoxin i from the cyanobacterium anabaena sp. strain pcc 7120. | the structural gene for ferredoxin i, petf, from the cyanobacterium anabaena sp. strain pcc 7120 has been isolated from a recombinant lambda library. mixtures of tetradecanucleotides and heptadecanucleotides, each containing all possible dna sequences corresponding to two separate regions of the ferredoxin amino acid sequence, were synthesized and used as hybridization probes to identify a genomic clone containing the coding sequence for the petf gene. the sequence of the entire petf coding regi ... | 1986 | 2430949 |
| green light induces transcription of the phycoerythrin operon in the cyanobacterium calothrix 7601. | phycobilisomes, the major light-harvesting complexes of cyanobacteria are multimolecular structures made up of chromophoric proteins called phycobiliproteins and non chromophoric linker polypeptides. we report here the isolation and nucleotide sequence of the genes, cpea and cpeb, which in calothrix pcc 7601 encode the alpha and beta subunits of phycoerythrin, one of the major phycobiliproteins. in calothrix pcc 7601, modulation of the polypeptide composition of the phycobilisomes occurs in resp ... | 1986 | 2431391 |
| effects of light deprivation on rna synthesis, accumulation of guanosine 3'(2')-diphosphate 5'-diphosphate, and protein synthesis in heat-shocked synechococcus sp. strain pcc 6301, a cyanobacterium. | the rate of total rna synthesis, the extent of guanosine 3'(2')-diphosphate 5'-diphosphate (ppgpp) accumulation, and the pattern of protein synthesis were studied in light-deprived and heat-shocked synechococcus sp. strain pcc 6301 cells. there was an inverse correlation between the rate of total rna synthesis and the pool of ppgpp, except immediately after a temperature shift up, when a parallel increase in the rate of rna synthesis and accumulation of ppgpp was observed. the inverse correlatio ... | 1987 | 2433265 |
| phycobilisome-associated glycoproteins in the cyanobacterium anacystis nidulans r 2. | four phycobilisome-associated proteins were found to be specifically reactive with the lectin concanavalin a after subunits of isolated anacystis nidulans r 2 phycobilisomes were separated on polyacrylamide gels and transferred onto nitrocellulose. the concanavalin a-reactive phycobilisome components have proposed functions related to the orientation, assembly, and membrane attachment of the phycobilisome. chemical analysis of the total isolated phycobilisome material indicated the presence of g ... | 1987 | 2438157 |
| transcriptional analysis of the cyanobacterial gvpabc operon in differentiated cells: occurrence of an antisense rna complementary to three overlapping transcripts. | cyanobacteria are photosynthetic prokaryotes able to colonize almost all kinds of ecosystems. some of them exhibit differentiation processes and/or may establish tight symbiotic associations. upon changes in the environmental conditions, the cyanobacterium calothrix 7601 differentiates hormogonia which are short filaments of small cells resulting from cellular division and fragmentation of the long filaments of vegetative cells. in calothrix, hormogonia are characterized by their gliding motilit ... | 1987 | 2450053 |
| transcriptional organization of the phycocyanin subunit gene clusters of the cyanobacterium anacystis nidulans utex 625. | the phycocyanin subunit gene cluster is duplicated on the chromosome of the cyanobacterium anacystis nidulans utex 625. the two gene clusters cpcb1a1 (left) and cpcb2a2 (right) are separated by about 2,500 base pairs, and in each cluster the beta-subunit gene is located upstream from the alpha-subunit gene. filter hybridizations with phycocyanin-specific probes to total rna detected at least two major transcripts that were 1,300 to 1,400 nucleotides long. besides these major mrna species, two mi ... | 1988 | 2454910 |
| genes encoding core components of the phycobilisome in the cyanobacterium calothrix sp. strain pcc 7601: occurrence of a multigene family. | the phycobilisome is the major light-harvesting complex of cyanobacteria. it is composed of a central core from which six rods radiate. allphycocyanin, an alpha beta oligomer (alpha ap and beta ap), is the main component of the core which also contains three other phycobiliproteins (alpha apb, beta 18.3, and l92cm) and a small linker polypeptide (l7.8c). by heterologous dna hybridization, two ecori dna fragments of 3.5 and 3.7 kilobases have been cloned from the chromatically adapting cyanobacte ... | 1988 | 2461358 |
| 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 |
| transformation of glutamate to delta-aminolevulinic acid by soluble extracts of chlorobium vibrioforme. | formation of the tetrapyrrole pigment precursor delta-aminolevulinic acid (ala) from glutamate was detected and partially characterized in extracts of the strictly anaerobic green photosynthetic bacterial species chlorobium vibrioforme by using assay methods derived from those developed for algae and cyanobacteria. ala formation in chlorobium extracts was saturated at 10 mm glutamate and required nadph and atp at optimal concentrations of 0.3 and 3 mm, respectively. preincubation of the enzyme e ... | 1989 | 2472378 |
| genetic analysis of phycobilisome mutants in the cyanobacterium synechococcus species pcc 6301. | the chromophoric protein phycocyanin is the major protein in the phycobilisome rod of the cyanobacterium synechococcus 6301 (formerly designated anacystis nidulans sp. utex 625). the gene clusters coding for the beta- and alpha-subunits of phycocyanin are duplicated on the chromosome of synechococcus 6301 and separated by an intergenic region 2.5 kb long. the structure of the phycocyanin operons of the phycobilisome mutant strains an112 and an135 was compared to that of wild-type synechococcus 6 ... | 1989 | 2473374 |
| heavy metal ion-induced changes of ribosomal rna synthesis in synechococcus sp. strain pcc 6301, a cyanobacterium. | we examined the effect of cadmium, zinc, copper and mercury ions on the rate of total rna synthesis and on the accumulation of ribosomal rnas in synechococcus sp. pcc 6301, an obligate photoautotrophic cyanobacterium. it was found that treatment of cells with growth-inhibitory concentrations of cadmium and zinc ions severely decreased the rate of total rna synthesis both under light (growing) and dark (non-growing) conditions, while copper and mercury ions had different inhibitory effects under ... | 1989 | 2484816 |
| 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 |
| isolation and characterization of dna-binding proteins from the cyanobacterium synechococcus sp. pcc 7002 (agmenellum quadruplicatum) and from spinach chloroplasts. | basic, low-molecular-weight dna-binding proteins were isolated from the unicellular cyanobacterium synechococcus sp. pcc 7002 (agmenellum quadruplicatum) and from the chloroplasts of spinach (spinacia oleacera). in synechococcus, two major proteins which bind to double-strand dna (10 and 16 kda, respectively) were purified. the 10 kda protein, named haq, resembles strongly, in amino-acid composition, eubacterial hu-type proteins. the 16 kda protein is slightly basic. its characteristics are comp ... | 1989 | 2491789 |
| dimer-tetramer equilibrium of glutathione reductase from the cyanobacterium spirulina maxima. | glutathione reductase [nad(p)h:gssg oxidoreductase; ec 1.6.4.2] from cyanobacterium spirulina maxima exists as an equilibrium system between a dimer (s20,w = 5.96) and a tetramer (s20,w = 8.49) which has a very slow interconversion rate at neutral ph. our results showed that the apparent dissociation constant (kd) was 4.61 x 10(-7) m. the proportion of both forms at ph 7.0 did not alter at either 4 or 25 degrees c. however, electrophoretic analysis at various ph values showed that at 25 degrees ... | 1989 | 2492181 |
| 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 |
| relationship between a 47-kda cytoplasmic membrane polypeptide and nitrate transport in anacystis nidulans. | the polypeptide composition of cytoplasmic membranes of the cyanobacterium anacystis nidulans changes in response to variations in the nitrogen source available to the cells, differing specifically in the amount of a polypeptide of 47-kda molecular mass. synthesis of the polypeptide and expression of nitrate transport activity are repressed by ammonium. transfer of ammonium-grown cells to a medium containing nitrate as the sole nitrogen source results in parallel development of the 47-kda polype ... | 1989 | 2492194 |
| 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 |
| sulfide induction of synthesis of a periplasmic protein in the cyanobacterium oscillatoria limnetica. | two proteins which may play a role in the induction of anoxygenic photosynthesis in oscillatoria limnetica have been demonstrated by comparing the pattern of labeling during pulses of [35s]methionine of cells incubated under inducing conditions [anaerobic conditions plus 3-(3,4-dichlorophenyl)-1,1-dimethylurea, light, and sulfide) with that of cells incubated under noninducing conditions (without sulfide). the major inducible protein has an apparent molecular mass of 11.5 kilodaltons and is asso ... | 1989 | 2492513 |
| structural characterization of toxic cyclic peptides from blue-green algae by tandem mass spectrometry. | combined use of chemical degradation, derivatization, and tandem mass spectrometry for rapid structural characterization of toxic cyclic peptides from blue-green algae at the nanomole level is described. previously, all blue-green algal toxins were thought to belong to a family of seven-residue cyclic peptides, having the general structure cyclo-d-ala-l-xaa-erythro-beta-methyl-d-isoaspartic acid-l-yaa-adda-d-isoglutamic acid-n-methyldehydroalanine, where xaa and yaa represent variable amino acid ... | 1989 | 2492662 |
| 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 |
| identification of an assembly domain in the small subunit of ribulose-1,5-bisphosphate carboxylase. | the mature small subunit (ssu) of ribulose-1,5-bisphosphate carboxylase/oxygenase (ec 4.1.1.39) in higher plants contains a highly conserved sequence of 16 amino acids that is absent in the ssus of cyanobacteria. to determine whether this region of the ssu of higher plants has a specific function, portions of the ssu genes (rbcs) of pea (pisum sativum) and the cyanobacterium anacystis nidulans were fused to create chimeric genes that either lacked or contained the coding sequence for the 16 cons ... | 1989 | 2493152 |
| interactive effects of nitrogen and copper on growth of cyanobacterium microcystis. | | 1989 | 2493272 |
| novel cytotoxic peptides from the tropical marine cyanobacterium hormothamnion enteromorphoides. 1. discovery, isolation and initial chemical and biological characterization of the hormothamnins from wild and cultured material. | a caribbean cyanobacterium, hormothamnion enteromorphoides, was found to produce a complex mixture of ichthyotoxic peptides, perhaps explaining the apparent absence of predation upon these potentially palatable life forms. bioassay-guided fractionation was used to isolate these toxic and antimicrobial natural products, and a variety of techniques including hr fab mass spectrometry, 2d-nmr, traditional hydrolysis-amino acid analysis, and several chemical reactions were used to define the basic st ... | 1989 | 2493387 |
| low-molecular-mass proteins in cyanobacterial photosystem ii: identification of psbh and psbk gene products by n-terminal sequencing. | the o2-evolving photosystem ii core complex was isolated from a thermophilic cyanobacterium, synechococcus vulcanus copeland. analysis by sds-polyacrylamide gel electrophoresis revealed that the complex contained at least seven low-molecular-mass proteins in addition to the well characterized cp47 apoprotein, cp43 apoprotein, 33 kda extrinsic protein, d1 protein, d2 protein and large subunit of cytochrome b-559. the separation of these low-molecular-mass proteins were very similar between cyanob ... | 1989 | 2493396 |
| 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 |
| occurrence and distribution of gas vesicle genes among cyanobacteria. | gas vesicles (gv) are specialized cell inclusions providing many aquatic procaryotes with buoyancy. in the cyanobacterium calothrix sp. strain pcc 7601, at least four genes are involved in gv formation. one of those, gvpa1, encodes the major structural gv protein (70 amino acids) and belongs to a multigene family (gvpa1, gvpa2, gvpd). the fourth gene, gvpc, encodes a 162-amino-acid protein, the function of which is still unclear. we used the calothrix gvpa1 and gvpc genes as probes to perform so ... | 1989 | 2493445 |
| state transitions in a phycobilisome-less mutant of the cyanobacterium synechococcus sp. pcc 7002. | state transitions were investigated in the cyanobacterium synechococcus sp. pcc 7002 in both wild-type cells and mutant cells lacking phycobilisomes. preillumination in the presence of dcmu induced state 1 and dark-adaptation induced state 2 in both wild-type and mutant cells as determined by 77 k fluorescence emission spectroscopy. light-induced transitions were observed in the wild-type after preferential excitation of phycocyanin (state 2) or preferential excitation of chl a (state 1). light- ... | 1989 | 2493811 |
| cyanobacterial rna polymerase genes rpoc1 and rpoc2 correspond to rpoc of escherichia coli. | the dna-dependent rna polymerase (ribonucleoside triphosphate:rna nucleotidyltransferase, ec 2.7.7.6) of cyanobacteria contains a unique core component, gamma, which is absent from the rna polymerases of other eubacteria (g. j. schneider, n. e. tumer, c. richaud, g. borbely, and r. haselkorn, j. biol. chem. 262:14633-14639, 1987). we present the complete nucleotide sequence of rpoc1, the gene encoding the gamma subunit, from the heterocystous cyanobacterium nostoc commune utex 584. the derived a ... | 1989 | 2495268 |
| 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 |
| effect of bimetallic combinations of ni, cr, and pb on growth, uptake of nitrate and ammonia, 14co2 fixation, and nitrogenase activity of nostoc muscorum. | the toxicity of cr, ni, and pb individually as well as in combination (cr + ni, cr + pb, ni + pb) on growth, final yield, uptake of no3- and nh4+, photosynthesis, and nitrogenase activity of nostoc muscorum has been studied. all test metals, when used individually, depicted toxicity against the above-mentioned processes of test cyanobacterium. however, their interactive effect was found to be mostly of antagonistic type. antagonism was more prevalent in those combinations containing nickel. in a ... | 1989 | 2496971 |
| determination of intracellular nitrate. | a sensitive procedure has been developed for the determination of intracellular nitrate. the method includes: (i) preparation of cell lysates in 2 m-h3po4 after separation of cells from the outer medium by rapid centrifugation through a layer of silicone oil, and (ii) subsequent nitrate analysis by ion-exchange h.p.l.c. with, as mobile phase, a solution containing 50 mm-h3po4 and 2% (v/v) tetrahydrofuran, adjusted to ph 1.9 with naoh. the determination of nitrate is subjected to interference by ... | 1989 | 2497740 |
| detection of a homologue to an e. coli glutamate synthase gene in a cyanobacterium. | the gltby locus of e. coli, which codes for the two subunits of pyridine nucleotide dependent glutamate synthase, was used as a probe to detect homologues in genomic dna of synechococcus pcc6301, a unicellular cyanobacterium. non-overlapping probes from gltb detected a single homologue with extensive homology, however glty probes do not detect a strong homologue. the possibility that the gltb homologue encodes a ferredoxin-dependent glutamate synthase of the type found in cyanobacteria, algae an ... | 1989 | 2498151 |
| insertional mutagenesis by random cloning of antibiotic resistance genes into the genome of the cyanobacterium synechocystis strain pcc 6803. | the facultative heterotrophic cyanobacterium synechocystis sp. strain pcc 6803 was transformed by haeii cmr fragments ligated at random to haeii dna fragments of the host genome. a similar transformation was done with an avaii kmr marker ligated to avaii host dna fragments. integration of the resistance markers into the host genome led to a high frequency of stable kmr and cmr transformants. physical analysis of individual transformants indicated that this result was due to homologous recombinat ... | 1989 | 2498291 |
| dna sequence and regulation of the gene (cbpa) encoding the 42-kilodalton cytoplasmic membrane carotenoprotein of the cyanobacterium synechococcus sp. strain pcc 7942. | the gene (cbpa) coding for a carotenoid-binding protein of the cyanobacterium synechococcus sp. strain pcc 7942 (anacystis nidulans r2) has been cloned and sequenced. a polyclonal antibody against the protein was used to identify immunoreactive clones from a lambda gt11 expression library of synechococcus strain pcc 7942. the initial positive clone (lambda gtan42) contained a 0.9-kilobase (kb) chromosomal fragment, which was used to detect a larger chromosomal fragment from a lambda embl3 librar ... | 1989 | 2498292 |
| genes for the ribosomal proteins s12 and s7 and elongation factors ef-g and ef-tu of the cyanobacterium, anacystis nidulans: structural homology between 16s rrna and s7 mrna. | a 6.5 kb region from the genome of the cyanobacterium, anacystis nidulans 6301 was cloned using the tobacco chloroplast gene for ribosomal protein s12 as a probe. sequence analysis revealed the presence of genes for ribosomal proteins s12 and s7 and elongation factors ef-g and ef-tu in this dna region. the arrangement is rps12 (124 codons) - 167 bp spacer - rps7 (156 codons) - 77 bp spacer - fus (694 codons) - 26 bp spacer - tufa (409 codons), which is similar to that of the escherichia coli str ... | 1989 | 2499762 |
| mutagenesis by random cloning of an escherichia coli kanamycin resistance gene into the genome of the cyanobacterium synechocystis pcc 6803: selection of mutants defective in photosynthesis. | photosynthetic mutants of the cyanobacterium synechocystis pcc 6803 were produced by a random cartridge mutagenesis method leading to gene inactivation. this procedure relies on random ligation of an escherichia coli kanamycin resistance (kmr) gene to restriction fragments of genomic dna from the host. then recombination occurring during transformation promotes integration of the marker gene into the genome of the recipient cells. several mutants impaired in photosynthesis were obtained by this ... | 1989 | 2499763 |
| characterization of the ndhc-psbg-orf157/159 operon of maize plastid dna and of the cyanobacterium synechocystis sp. pcc6803. | the ndhc and orf159 genes of the maize plastid dna (ptdna) were sequenced and maize orf159 was used to screen a library of genomic dna of the blue-green alga synechocystis sp. pcc 6803. the cyanobacterial gene homologous to orf159 (orf157) was isolated and sequenced. in sequencing the region upstream of orf157, reading frames with homology to the ndhc and psbg genes of maize ptdna were identified. the ndhc and psbg genes overlap in the ptdnas of maize, tobacco and marchantia polymorpha, but are ... | 1989 | 2499764 |
| nucleotide sequence of a second psba gene from the unicellular cyanobacterium synechocystis 6803. | | 1989 | 2499875 |
| differential expression of members of a cyanobacterial psba gene family in response to light. | the genome of the cyanobacterium synechococcus sp. strain pcc 7942 contains three psba genes encoding two forms of the d1 protein: form i, the product of psbai, differs from form ii, the product of both psbaii and psbaiii, at 25 of 360 residues. d1 is essential for photosynthesis as a core component of the photosystem ii reaction center. translational gene fusions between each of the synechococcus psba genes and the escherichia coli lacz gene were inserted into the chromosome of wild-type synech ... | 1989 | 2500419 |
| nontoxic and toxic oligopeptides with d-amino acids and unusual residues in microcystis aeruginosa pcc 7806. | toxic and nontoxic peptides were isolated from the cyanobacterium microcystis aeruginosa pcc 7806 by a procedure including extraction of cells with water-saturated 1-butanol, chromatography of the extract on silica gel plates and high performance liquid chromatography (hplc) on partisil-5. the toxin was shown to be only a minor constituent, being negatively charged and thus separable by electrophoresis, within the hplc-purified fraction. it contained erythro-beta-methyl-d-asp, d-glu, d-ala, l-le ... | 1989 | 2500922 |
| chlorophyll precursors in the plasma membrane of a cyanobacterium, anacystis nidulans. characterization of protochlorophyllide and chlorophyllide by spectrophotometry, spectrofluorimetry, solvent partition, and high performance liquid chromatography. | plasma membranes were isolated and separated from thylakoid membranes by discontinuous sucrose density gradient centrifugation of crude membranes prepared by french pressure cell extrusion of lysozyme-treated anacystis nidulans. two distinct populations of chlorophyll-free plasma membrane vesicles were obtained exhibiting buoyant densities of 1.087 and 1.100 g/cm3 as opposed to a uniform density of 1.192 g/cm3 for thylakoid membranes. plasma and thylakoid membranes were characteristically differ ... | 1989 | 2501298 |
| novel water stress protein from a desiccation-tolerant cyanobacterium. purification and partial characterization. | a desiccation-tolerant cyanobacterium nostoc commune accumulates a novel group of acidic proteins when colonies are subjected to repeated cycles of drying and rehydration. the proteins occur in high concentrations; they have isoelectric points between 4.3 and 4.8 and apparent molecular masses between 30 and 39 kda. the purification of three of these proteins with molecular masses of 33, 37, and 39 kda is described. the amino-terminal sequence of the 39-kda protein is ala-leu-tyr-gly-tyr-thr-ile- ... | 1989 | 2501307 |
| 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 |
| gene sequence for the 9 kda component of photosystem ii from the cyanobacterium phormidium laminosum indicates similarities between cyanobacterial and other leader sequences. | a 9 kda polypeptide which is loosely attached to the inner surface of the thylakoid membrane and is important for the oxygen-evolving activity of photosystem ii in the thermophilic cyanobacterium phormidium laminosum has been purified, a partial amino acid sequence obtained and its gene cloned and sequenced. the derived amino acid sequence indicates that the 9 kda polypeptide is initially synthesised with an n-terminal leader sequence of 44 amino acids to direct it across the thylakoid membrane. ... | 1989 | 2501648 |
| light-independent nadph-protochlorophyllide oxidoreductase activity in purified plasma membrane from the cyanobacterium anacystis nidulans. | a light plasma membrane fraction corresponding to a buoyant density of 1.087 +/- 0.005 g/cm3 and devoid of chlorophyll was prepared and purified from anacystis nidulans according to a recently published procedure (g.a.peschek, v.molitor, m.trnka, m. wastyn and w. erber (1988) methods enzymol. 167, 437-449). besides major amounts of carotenoids the plasma membranes contained a small but significant pool of chlorophyllide a and protochlorophyllide a as verified by room temperature and 77k spectrof ... | 1989 | 2502114 |
| a model system for studying the bioavailability of intestinally administered microcystin-lr, a hepatotoxic peptide from the cyanobacterium microcystis aeruginosa. | sprague-dawley rats were used to evaluate a model system for studying the hepatotoxicity caused by microcystin-lr (mcyst-lr), a toxin produced by the cyanobacterium (blue-green alga) microcystis aeruginosa, and for evaluating the in vivo therapeutic potential of cholestyramine resin (ctr) which was found to bind the toxin in vitro. female rats were treated with either toxin or an equivalent volume of the saline vehicle by direct administration into the lumen of an in situ isolated ileal loop. ma ... | 1989 | 2502775 |
| n-terminal sequencing of low-molecular-mass components in cyanobacterial photosystem ii core complex. two components correspond to unidentified open reading frames of plant chloroplast dna. | we recently reported the presence of several low-molecular-mass protein components in the ps ii o2-evolving core complex from the thermophilic cyanobacterium, synechococcus vulcanus [(1989) febs lett. 244, 391-396]. here we have characterized the three components (4.1, 4.7, 5 kda) of the same cyanobacterial core complex by n-terminal sequencing. there were two components in the 4.7 kda region, both having a blocked n-terminus. one has a sequence highly homologous to open reading frame 34 of plan ... | 1989 | 2503398 |
| identification of photosystem i components from the cyanobacterium, synechococcus vulcanus by n-terminal sequencing. | the photosystem i core complex isolated from a thermophilic cyanobacterium, synechococcus vulcanus, is composed of eight low-molecular-mass proteins of 18, 14, 12, 9.5, 9, 6.5, 5 and 4.1 kda in addition to the ps i chlorophyll protein. n-terminal amino acid sequences of all these components were determined and compared with those of higher plants. clearly, the 9.5 kda component corresponds to the protein which carries the non-heme iron-sulfur centers a and b. this protein is so poorly visualized ... | 1989 | 2503399 |
| a cyanobacterial mutant requiring the expression of ribulose bisphosphate carboxylase from a photosynthetic anaerobe. | ribulose bisphosphate carboxylase is essential for both photoautotrophic and photoheterotrophic growth of the cyanobacterium synechocystis 6803. however, a mutant lacking cyanobacterial carboxylase could be obtained by replacing the natural carboxylase gene with the corresponding gene from rhodospirillum rubrum, a photosynthetic anaerobe. this treatment produced an organism whose growth depended on the activity of the structurally and functionally dissimilar foreign carboxylase. as a further con ... | 1989 | 2503824 |
| two functional psbd genes in the cyanobacterium synechococcus sp. strain pcc 7942. | the cyanobacterium synechococcus sp. strain pcc 7942 has two copies of the psbd gene which encodes the d2 polypeptide of the photosystem ii (psii) reaction center. one of the genes, psbdi, overlaps the open reading frame of another photosystem ii gene, psbc; the psbdii gene is monocistronic. gene inactivation experiments had previously shown that psbdii is dispensable under normal laboratory growth conditions. however, similar experiments with psbdi never produced viable psbdi-inactivated mutant ... | 1989 | 2504695 |
| 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 |
| electrophoretic and immunological comparisons of chloroplast and prokaryotic ribosomal proteins reveal that certain families of large subunit proteins are evolutionarily conserved. | antibodies to individual chloroplast ribosomal (r-)proteins of chlamydomonas reinhardtii synthesized in either the chloroplast or the cytoplasm were used to examine the relatedness of chlamydomonas r-proteins to r-proteins from the spinach (spinacia oleracea) chloroplast, escherichia coli, and the cyanobacterium anabaena 7120. in addition, 35s-labeled chloroplast r-proteins from large and small subunits of c. reinhardtii were co-electrophoresed on 2-d gels with unlabeled r-proteins from similar ... | 1989 | 2504932 |
| characterization of the str operon genes from spirulina platensis and their evolutionary relationship to those of other prokaryotes. | a 5.3 kb dna segment containing the str operon (ca. 4.5 kb) of the cyanobacterium spirulina platensis has been sequenced. the str operon includes the structural genes rpsl (ribosomal protein s12), rpsg (ribosomal protein s7), fus (translation elongation factor ef-g) and tuf (translation elongation factor ef-tu). from the nucleotide sequence of this operon, the primary structures of the four gene products have been derived and compared with the available corresponding structures from eubacteria, ... | 1989 | 2505055 |
| catechol stimulation of ferricyanide hill reaction by spheroplasts of cyanobacterium, synechococcus cedrorum: effect of temperature on catechol-stimulated oxygen evolution. | catechol(o-dihydroxybenzene) at low concentrations (20-100 microm) stimulates fecn-dependent o2 evolution of spheroplasts isolated from the cyanobacterium synechococcus both in the presence and absence of dbmib, an inhibitor of electron flow from psii to psi, the stimulation being two-fold with saturating concentration of (60 microm) catechol. catechol thus appears to mediate the acceptance of electrons at the reducing side of psii. similarly it may act on the component of electron donor to psii ... | 1989 | 2506124 |
| adaptive eradication of methionine and cysteine from cyanobacterial light-harvesting proteins. | sulphur is unique among the main elements of living cells in that it is covalently bound to biopolymers but does not occur in the biopolymer backbone. indeed, most of the bacterial sulphur content resides in the methionine and cysteine side-chains of proteins. the growth yield of an organism under conditions of sulphur limitation could therefore be greatly enhanced by mutations that substitute met and cys in the organism's proteins for sulphur-free amino acids. because the saving in sulphur woul ... | 1989 | 2506452 |
| occurrence of the hepatotoxic cyanobacterium nodularia spumigena in the baltic sea and structure of the toxin. | water blooms formed by potentially toxic species of cyanobacteria are a common phenomenon in the baltic sea in late summer. twenty-five cyanobacterial bloom samples were collected from open and coastal waters of the baltic sea during 1985 to 1987, and their toxicity was determined by mouse bioassay. all of 5 bloom samples from the southern baltic sea, 6 of 6 from the open northern baltic sea (gulf of finland), and 7 of 14 finnish coastal samples were found to contain hepatotoxic cyanobacteria. n ... | 1989 | 2506812 |
| in vitro carotenogenesis and characterization of the phytoene desaturase reaction in anacystis. | an in vitro system for carotenogenesis has been developed from the cyanobacterium anacystis. precursor conversion is highly effective and almost no colored intermediates before beta-carotene accumulate. these cell-free reactions have been employed to characterize the phytoene desaturation reaction. phytoene desaturation is dependent on nad(p)+ and oxygen but insensitive to inhibitors of plant-type monooxygenases. this result suggests a hydride/proton transfer as mechanism for insertion of a doub ... | 1989 | 2506858 |
| regulation of expression and nucleotide sequence of the anabaena variabilis reca gene. | the expression of the cyanobacterial reca gene, isolated from anabaena variabilis, has been examined at the levels of transcript and protein abundance. exposure of the cyanobacterium to a variety of dna-damaging agents, including mitomycin c, methyl methanesulfonate, and uv irradiation, results in a rapid increase in the abundance of the reca transcript above basal levels as determined by northern (rna) blot analysis. a concomitant increase in the abundance of a 37- to 38-kilodalton polypeptide ... | 1989 | 2507530 |
| transformation of a filamentous cyanobacterium by electroporation. | the filamentous cyanobacterium anabaena sp. strain m131 was transformed with the shuttle vector prl6 by electroporation. optimum conditions for electroporation required relatively high field strengths with short time constants. restriction significantly lowered the efficiency of transformation. a plasmid containing a single unmodified avaii restriction site transformed cells with about 100-fold-lower efficiency than did the same plasmid with a modified restriction site. | 1989 | 2507531 |
| molecular and genetical analysis of the fructose-glucose transport system in the cyanobacterium synechocystis pcc6803. | complementation for glucose transport capacity of deficient mutants from synechocystis pcc6803 allowed the cloning of the corresponding gene, glcp. the protein predicted from one open reading frame (orf) in the dna sequence was 468 residues long. it showed 46-60% amino acid sequence homology and similarity in size and predicted structure (including twelve probable membrane-spanning regions) with a group of non-phosphorylating sugar transporters from mammals, yeasts and escherichia coli. a second ... | 1989 | 2507869 |
| nucleotide sequence of the psbk gene of the cyanobacterium, anacystis nidulans 6301. | | 1989 | 2508063 |
| structure and toxicity of a peptide hepatotoxin from the cyanobacterium oscillatoria agardhii. | a peptide hepatotoxin was isolated by reversed phase liquid chromatography from the cyanobacterium oscillatoria agardhii and characterized structurally and toxicologically. amino acid analyses, proton nuclear magnetic resonance and fast atom bombardment mass spectrometry showed that the toxin is a cyclic heptapeptide (mol. wt 1023.5) with the structure cyclo-(ala-arg-asp-arg-adda-glu-n-methyldehydroala) (adda: 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid). in mice the toxic e ... | 1989 | 2508270 |
| effects of three pesticides on msx-induced ammonia photoproduction by the cyanobacterium nostoc linckia. | three pesticides (2,4-d, basalin, aldrin) inhibited l-methionine-dl-sulfoximine (msx)-induced photoproduction of ammonia by the nitrogen-fixing cyanobacterium nostoc linckia. combinations of pesticides and msx were inhibitory except at low concentrations (100 and 500 micrograms/ml) of 2,4-d which stimulated nh+4 production. similar results were obtained when pesticides were added 6 hr after the addition of msx, but the inhibition was weaker. when msx was added to the culture 6 hr after the addit ... | 1989 | 2509191 |
| physical and genetic maps of the genome of the heterocyst-forming cyanobacterium anabaena sp. strain pcc 7120. | a restriction map of the chromosome of the cyanobacterium anabaena sp. strain pcc 7120 was generated by the determination of the order of restriction fragments of the infrequently cleaving restriction endonucleases avrii, sali, and psti. these restriction fragments were resolved by the pulsed homogeneous orthogonal field gel electrophoresis system of pulsed-field gel electrophoresis (i. bancroft and c. p. wolk, nucleic acids res. 16:7405-7418, 1988). other infrequently cutting restriction endonu ... | 1989 | 2509424 |
| the 5'-flanking region of the gene encoding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase is crucial for growth of the cyanobacterium synechococcus sp. strain pcc 7942 at the level of co2 in air. | transformation of the high-co2-requiring mutants (hcr) o221 and e1 derived from the cyanobacterium synechococcus sp. strain pcc 7942 by a wild-type dna library restored their ability to grow at the level of co2 in air. a plasmid (pe12) containing a 10-kilobase dna insert was rescued from a o221 heterogenote and proved to transform both o221 and e1 to the wild-type phenotype. the capacity of the pe12 subclones to confer the wild-type phenotype to o221 transformants enabled the mapping of the muta ... | 1989 | 2509426 |
| photosynthetic co2 fixation and ribulose bisphosphate carboxylase/oxygenase activity of nostoc sp. strain ucd 7801 in symbiotic association with anthoceros punctatus. | the cyanobacterium nostoc sp. strain ucd 7801, immediately after separation from pure cultures of a reconstituted symbiotic association with the bryophyte anthoceros punctatus, exhibited a rate of light-dependent co2 fixation that was eightfold lower than that measured in the free-living growth state. ribulose bisphosphate carboxylase/oxygenase (rubpc/o) specific activity was also eightfold lower in cell extracts of symbiotic strain 7801 relative to that in free-living cultures. the in vitro act ... | 1989 | 2509431 |
| structure and targeted mutagenesis of the gene encoding 8-kda subunit of photosystem i from the cyanobacterium synechocystis sp. pcc 6803. | photosystem i reaction center of the cyanobacterium synechocystis sp. pcc 6803 contains seven different polypeptide subunits. the subunit with a molecular mass of about 8 kda was isolated, and the sequence of its amino-terminal residues was determined. oligonucleotide probes corresponding to this sequence were used to isolate the gene encoding this subunit. the gene, termed as psae, codes for a polypeptide with a mass of 8075 da. it is present as a single copy in the genome and is transcribed as ... | 1989 | 2509456 |
| insertional inactivation of the gene encoding subunit ii of photosystem i from the cyanobacterium synechocystis sp. pcc 6803. | the cyanobacterium synechocystis sp. pcc 6803 carries out oxygenic photosynthesis analogous to higher plants. its photosystem i contains seven different polypeptide subunits. the cartridge mutagenesis technique was used to inactivate the psad gene which encodes subunit ii of photosystem i. a mutant strain lacking subunit ii was generated by transforming wild type cells with cloned dna in which psad gene was interrupted by a gene conferring kanamycin resistance. the photoautotrophic growth of mut ... | 1989 | 2509457 |
| directed alteration of the d1 polypeptide of photosystem ii: evidence that tyrosine-161 is the redox component, z, connecting the oxygen-evolving complex to the primary electron donor, p680. | in photosystem ii, electrons are sequentially extracted from water at a site containing mn atoms and transferred through an intermediate carrier (z) to the photooxidized reaction-center chlorophyll (p680+). two polypeptides, d1 and d2, coordinate the primary photoreactants of the reaction center. recently debus et al. [debus, r.j., barry, b.a., babcock, g.t., & mcintosh, l. (1988) proc. natl. acad. sci. u.s.a. 85, 427-430], have suggested that z is a tyrosine residue located at position 161 of t ... | 1989 | 2510819 |
| duplication of the phycocyanin operon in the unicellular cyanobacterium anacystis nidulans r2. | two phycocyanin (pc) operons, each containing alpha- and beta-subunit genes, have been isolated from the unicellular cyanobacterium anacystis nidulans r2. using oligodeoxyribonucleotide probes for the pc-coding regions, three psti fragments were obtained and shown to contain the two operons, which are 2.7 kb apart, with a proposed gene order of 5'-(beta i-alpha i)-(beta ii-alpha ii)-3'. the nucleotide sequences of both alpha-subunit genes are identical, as are the beta-sequences and the 51-bp in ... | 1989 | 2511077 |
| determination of anatoxin-a, the neurotoxin of anabaena flos-aquae cyanobacterium, in algae and water by gas chromatography-mass spectrometry. | | 1989 | 2512321 |
| nucleotide sequence of the gene proposed to encode the small subunit of the soluble hydrogenase of the thermophilic unicellular cyanobacterium synechococcus pcc 6716. | | 1989 | 2513553 |
| use of degenerate oligonucleotides for amplification of the nifh gene from the marine cyanobacterium trichodesmium thiebautii. | trichodesmium spp. are marine filamentous, nonheterocystous, nitrogen-fixing cyanobacteria which are an important component of marine ecosystems. this organism has never been maintained in axenic culture, and there has remained some doubt as to the identity of the organism responsible for nitrogen fixation in trichodesmium aggregates. by using degenerate oligonucleotide primers, it has been possible to amplify, clone, and sequence a segment of the nifh gene from a natural assemblage of trichodes ... | 1989 | 2513774 |
| a promoter-probe vector-host system for the cyanobacterium, synechocystis pcc6803. | a vector-host system for testing promoters in the cyanobacterium synechocystis pcc6803 has been constructed. it relies on a small escherichia coli promoter-probe plasmid, pff11, which has four unique restriction sites in a polylinker upstream from the cat reporter gene. this plasmid is able to obtain a cyanobacterial origin of replication by homologous recombination with the resident plasmid of the recipient host, generating a new e. coli-synechocystis pcc6803 shuttle vector. this plasmid does n ... | 1989 | 2515116 |
| [cloning the alpha-amylase gene of bacillus amyloliquefaciens in cyanobacteria cells]. | the recombinant plasmids of piah4amy series were constructed containing the alpha-amylase gene of bacillus amyloliquefaciens a50 with its own promoter and leading sequence within an integrative vector plasmid piah4 (cmr) for cyanobacterium anacystis nidulans r2. at anacystis nidulans transformation the hybrid plasmids integrate into cyanobacterium chromosome with high efficiency and all cmr transformants produce alpha-amylase. expression of bacillar alpha-amylase gene in cyanobacterium cells is ... | 1989 | 2515431 |
| characteristics of the methylammonium/ammonium transport systems of the nitrogen-fixing cyanobacterium anabaena 7120 (atcc 27893). | nh4(+)-transport in anabaena 7120 was studied using the nh4+ analogue, 14ch3nh3+. at ph 7, two energy-dependent nh4(+)-transport systems were detected in both n2- and no3(-)-grown cells, but none in nh4(+)-grown cells. both transport systems showed a low and a high affinity mode of operation depending on the substrate concentration. one of the transport systems showed km values of 8 microm (vmax = 1 nmole min-1mg-1protein) and 80 microm (vmax = 7 nmole min-1mg-1protein), and was insensitive to l ... | 1989 | 2516834 |
| effect of anatoxin-a(s) from anabaena flos-aquae nrc-525-17 on blood pressure, heart rate, respiratory rate, tidal volume, minute volume, and phrenic nerve activity in rats. | the effects of anatoxin-a(s) [antx-a(s)] from the cyanobacterium anabaena flos-aquae nrc-525-17 on mean arterial blood pressure, heart rate, respiratory rate, tidal volume, minute volume, and phrenic nerve activity were evaluated in anesthetized sprague-dawley rats. anatoxin-a(s) was administered by continuous intravenous infusion. the initial effect of the toxin was to slow the heart rate and reduce arterial blood pressure, followed by much more pronounced reductions in these parameters. the ma ... | 1989 | 2517795 |
| nucleotide sequence of the gene encoding the 33 kda water oxidizing polypeptide in anabaena sp. strain pcc 7120 and its expression in escherichia coli. | the 33 kda extrinsic polypeptide of photosystem ii, also known as the manganese-stabilizing polypeptide (msp), is located on the lumen side of the thylakoid and is involved in water oxidation. the gene for msp, designated woxa, has been cloned from the nitrogen-fixing filamentous cyanobacterium anabaena and sequenced. the woxa open reading frame was found to be 819 bp. the deduced amino acid sequence was 63% and 59% homologous with that of synechococcus and synechocystis, respectively, and 44% c ... | 1989 | 2518833 |
| molecular analysis of psba mutations responsible for various herbicide resistance phenotypes in synechocystis 6714. | mutations conferring herbicide resistance in 3 mutant strains of the cyanobacterium synechocystis 6714 have been characterized by gene cloning and sequencing. the mutants display very different phenotypes: dcmu-iia is dcmu-resistant and atrazine-resistant, dcmu-iib is dcmu-resistant and atrazine-sensitive, and az-v is dcmu-sensitive, atrazine-resistant and presents particular photoinhibition properties. these mutants were originally obtained either by one-step selection (dcmu-iia) or by two-step ... | 1989 | 2518834 |
| influence of light on accumulation of photosynthesis-specific transcripts in the cyanobacterium synechocystis 6803. | transcript accumulation for the psba, psbd, psbd-c, rbcl-s and rrn genes in synechocystis 6803 was followed under different light conditions. psba, psbd, psbd-c and rbcl-s transcripts required light to accumulate and the relative abundance of these transcripts differed between high and low light conditions. under high light conditions, steady-state levels of psba, psbd and psbd-c transcripts were higher while levels of rbcl-s transcripts were lower than under low light conditions. rrn transcript ... | 1989 | 2518835 |
| cloning and expression of the branching enzyme gene (glgb) from the cyanobacterium synechococcus sp. pcc7942 in escherichia coli. | using the glgb gene from escherichia coli as a hybridization probe, the gene encoding the branching enzyme of the cyanobacterium synechococcus sp. pcc7942 has been identified on a 3.9-kb psti fragment which was cloned into plasmid puc9. two types of plasmids have been isolated. plasmid pkvn1 was expressing the synechococcus sp. gene as was shown by complementation of the glgb mutation of e. coli kv832. plasmid pkvn2, which carried the same insert in the opposite orientation was unable to complem ... | 1989 | 2527779 |
| purification of an acidic plastocyanin from microcystis aeruginosa. | plastocyanin and cytochrome c-553 are two functionally equivalent electron carriers in the photosynthetic chain of cyanobacteria. microcystis aeruginosa, a unicellular cyanobacterium which grows well at a high ph (8.6) and which was not known to possess plastocyanin, has been studied for its ability to synthesize plastocyanin in culture media with and without cu. in the absence of cu, an acidic cytochrome c-553 alone was isolated. with the inclusion of 2 microm cu, cytochrome c-553 synthesis was ... | 1989 | 2537099 |
| the amino acid sequence of cytochrome c553 from microcystis aeruginosa. | cytochrome c553 is an electron donor to p700 in the photosynthetic electron transfer chain of cyanobacteria and eukaryotic algae. we have purified this cytochrome from the cyanobacterium microcystis aeruginosa and determined its amino acid sequence. when the amino acid sequence of this protein is compared to sequences of cytochromes c553 from other organisms, one sees that the evolution of net charge is more pronounced than the evolution of overall structure, further documenting a pronounced shi ... | 1989 | 2539045 |
| the amino acid sequence of low-potential cytochrome c550 from the cyanobacterium microcystis aeruginosa. | the low-potential cytochrome c550 has been purified from the cyanobacterium microcystis aeruginosa and its amino acid sequence has been determined. the protein contains 135 amino acid residues with the cys-x-x-cys-his heme binding site at residues 37 to 41. the sequence from residue 28 to 45 shows similarity to cytochrome c553 residues 1 to 18 when the heme binding sites are aligned. another region of similarity is in the carboxyl-terminal regions of these two proteins. the two aligning regions ... | 1989 | 2539046 |
| characterization of the cytochrome c oxidase in isolated and purified plasma membranes from the cyanobacterium anacystis nidulans. | functionally intact plasma membranes were isolated from the cyanobacterium (blue-green alga) anacystis nidulans through french pressure cell extrusion of lysozyme/edta-treated cells, separated from thylakoid membranes by discontinuous sucrose density gradient centrifugation, and purified by repeated recentrifugation. origin and identity of the chlorophyll-free plasma membrane fraction were confirmed by labeling of intact cells with impermeant protein markers, [35s]diazobenzenesulfonate and fluor ... | 1989 | 2545245 |
| phosphomonoesterase activity of the cyanobacterium (blue-green alga) calothrix parietina. | cellular and extracellular phosphomonoesterase activities were compared in calothrix parietina d550, a strain whose original environment has been studied in detail. activity in both fractions became detectable at about the same stage in batch culture. differences in the influence of environmental factors between the two were slight, suggesting a common origin. the optimum temperatures for cellular and extracellular activities were 40 degrees c and 30 degrees c, respectively, and the upper limits ... | 1989 | 2549342 |
| partial amino acid sequence of fructose-1,6-bisphosphatase from the blue-green algae synechococcus leopoliensis. | purified fructose-1,6-bisphosphatase from the cyanobacterium synechococcus leopoliensis was s-carboxymethylated and cleaved with trypsin. the resulting peptides were purified by reversed-phase high performance liquid chromatography and the amino acid sequence of six of the purified peptides was determined by gas-phase microsequencing. the results revealed sequence homology with other fructose-1,6-bisphosphatases. the obtained sequence data provides information required for the design of oligonuc ... | 1989 | 2550924 |
| biosynthesis of 130-kilodalton mosquito larvicide in the cyanobacterium agmenellum quadruplicatum pr-6. | the 130-kilodalton mosquito larvicidal gene, cloned from bacillus thuringiensis var. israelensis, was introduced into the cyanobacterium agmenellum quadruplicatum pr-6 by plasmid transformation. transformed cells synthesized 130-kilodalton delta-endotoxin protein and showed mosquito larvicidal activity. results demonstrate a potential use of a cyanobacterium for biological control of mosquitoes. | 1989 | 2552921 |
| characterization of an insertion sequence (is891) of novel structure from the cyanobacterium anabaena sp. strain m-131. | when recombinant plasmids that were transferred to the cyanobacterium anabaena sp. strain m-131 were transferred back to escherichia coli, some of the transformants contained inserts. one of the insertion sequences (iss) was characterized by sequencing. this 1,351-base-pair is contained an open reading frame that was capable of encoding a peptide of 310 amino acids and had terminal sequences with distinctive structures, but it lacked terminal inverted repeats and did not duplicate target dna upo ... | 1989 | 2553665 |
| nitrogen fixation (nif) genes of the cyanobacterium anabaena species strain pcc 7120. the nifb-fdxn-nifs-nifu operon. | a second nitrogen fixation (nif) operon in the cyanobacterium (blue-green alga) anabaena (nostoc) sp. strain pcc 7120 has been identified and sequenced. it is located just upstream of the nifhdk operon and consists of four genes in the order nifb, fdxn, nifs, and nifu. the three nif genes were identified on the basis of their similarity with the corresponding genes from other diazotrophs. the fourth gene, fdxn, codes for a bacterial type ferredoxin (mulligan, m. e., buikema, w. j., and haselkorn ... | 1989 | 2553733 |
| purification and properties of glutamine synthetase from the non-n2-fixing cyanobacterium phormidium laminosum. | soluble glutamine synthetase activity (l-glutamate:ammonia ligase, adp forming, ec 6.3.1.2) was purified to electrophoretic homogeneity from the filamentous non-n2-fixing cyanobacterium phormidium laminosum (oh-1-p.cl1) by using conventional purification procedures in the absence of stabilizing ligands. the pure enzyme showed a specific activity of 152 mumol of gamma-glutamylhydroxamate formed.min-1 (transferase activity), which corresponded to 4.4 mumol of pi released.min-1 (biosynthetic activi ... | 1989 | 2563365 |
| impact of chromium and tin on a nitrogen-fixing cyanobacterium anabaena doliolum: interaction with bivalent cations. | the toxicity of chromium and tin on growth, uptake of no3- and nh4+, nitrate reductase and glutamine synthetase activity of anabaena doliolum, and its interaction with bivalent cations, viz. ca2+, mg2+, mn2+, ni2+, co2+, and zn2+, has been studied. some interacting cations, viz. ca, mg, and mn, substantially antagonized the toxic effects of chromium and tin with reference to growth and nutrient (no3- and nh4+) uptake in the hierarchical sequence ca greater than mg greater than mn, whereas the se ... | 1989 | 2565805 |
| protective effects of certain natural and synthetic complexans on the toxicity of chromium and tin to a n2-fixing cyanobacterium, anabaena doliolum. | the effects of chromium and tin on survival, growth, carbon fixation, nitrate reduction, ammonia assimilation, and nitrogenase activity of a n2-fixing cyanobacterium. anabaena doliolum, and their amelioration by synthetic and natural complexans, viz., edta, nitrilotriacetic acid (nta), pyridine dicarboxylic acid (pda), and citrate, have been studied. chromium proved to be much more toxic than tin, as it inhibited growth yield (49%), carbon fixation (53%), and nitrate reductase (79%), glutamine s ... | 1989 | 2575394 |
| comparison of in vivo and in vitro toxic effects of microcystin-lr in fasted rats. | the toxic effects of microcystin-lr, a cyclic heptapeptide isolated from the cyanobacterium microcystis aeruginosa, were studied in the fasted rat model and in subcellular fractions from fasted, toxin-treated and control rats. hepatotoxic effects of a lethal dose (100 micrograms/kg) were examined 15-90 min post-injection. elevations of serum enzymes, particularly sorbitol dehydrogenase, specific for liver mitochondria, correlated with hepatic damage. electron micrographs showed progressive cellu ... | 1989 | 2617540 |
| psba genes indicate common ancestry of prochlorophytes and chloroplasts. | it has long been suspected that chloroplasts evolved after an endosymbiotic event involving a photosynthetic prokaryote, presumably a cyanobacterium, and a eukaryotic organism. recent studies have provided strong evidence about the cyanobacterial nature of chloroplasts. since the discovery of prochlorophytes, oxygen-evolving photosynthetic prokaryotes containing chlorophyll a and chlorophyll b and lacking phycobiliproteins, there has been speculation that these represent evolutionary intermediat ... | 1989 | 2643058 |
| the plastid rpoa gene encoding a protein homologous to the bacterial rna polymerase alpha subunit is expressed in pea chloroplasts. | the gene rpoa, encoding a protein homologous to the alpha subunit of rna polymerase from escherichia coli has been located in pea chloroplast dna downstream of the petd gene for subunit iv of the cytochrome b-f complex. nucleotide sequence analysis has revealed that rpoa encodes a polypeptide of 334 amino acid residues with a molecular weight of 38916. northern blot analysis has shown that rpoa is co-transcribed with the gene for ribosomal protein s11. a lacz-rpoa gene-fusion has been constructe ... | 1989 | 2671652 |