Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| generation of lysoglyceroglycolipids in the cyanobacterium, phormidium tenue. | two kinds of lysoglycolipids, monogalactosyl 1-monoacylglycerol and digalactosyl 1-monoacylglycerol were generated in the cyanobacterium, phormidium tenue, when it was stored at -20 degrees for more than 1 month. by comparison of the compositions of fatty acid residues between monogalactosyl 1-monoacylglycerol and monogalactosyl diacylglycerol, digalactosyl 1-monoacylglycerol and digalactosyl diacylglycerol, respectively, the 1-monoacylgalactolipids were presumed to be formed by regioselective d ... | 1992 | 1368418 |
| conjugative gene transfer in marine cyanobacteria: synechococcus sp., synechocystis sp. and pseudanabaena sp. | versatility of gene transfer by transconjugation in marine cyanobacteria was demonstrated. in this study, seven different marine cyanobacteria were used as recipient cells. first, transconjugation was carried out using the mobilizable transposon (tn5) carrying plasmid psup1021. transconjugates were observed in all marine cyanobacteria tested. second, the broad-host-range vector pkt0230 (incq) was tested for transconjugation. pkt230 has been successfully transferred in a marine cyanobacterium syn ... | 1992 | 1368911 |
| cytoskeletal changes in hepatocytes induced by microcystis toxins and their relation to hyperphosphorylation of cell proteins. | the heptapeptide toxins produced by the blue-green alga (cyanobacterium) microcystis aeruginosa are selectively hepatotoxic in mammals. the characteristic post-mortem pathology of the liver is extensive lobular disruption due to sinusoidal breakdown, leakage of blood into the tissue and hepatocyte disintegration. isolated hepatocytes incubated with toxin show severe structural deformity and surface blebbing. this paper demonstrates the effects of microcystis toxins on the contraction and aggrega ... | 1992 | 1370395 |
| sequence of the ribonuclease p rna gene from the cyanobacterium anacystis nidulans. | 1992 | 1371871 | |
| light-regulated expression of the psbd gene family in synechococcus sp. strain pcc 7942: evidence for the role of duplicated psbd genes in cyanobacteria. | the genome of the cyanobacterium synechococcus sp. strain pcc 7942 contains two psbd genes encoding the d2 protein of the photosystem ii reaction center: psbdi, which is cotranscribed as a discistronic message with psbc (the gene encoding cp43, a chlorophyll-a binding protein), and psbdii, which is monocistronic. northern blot analysis of psbd transcripts showed that the two genes responded differently when wild-type cells were shifted from moderate to high light intensity. whereas psbdii transc ... | 1992 | 1372952 |
| protective effects of ca2+, mg2+, cu2+, and ni2+ on mercury and methylmercury toxicity to a cyanobacterium. | toxicological investigations of the impact of inorganic mercury (hg2+) and methylmercury (ch3hg+) in terms of growth, nh4+ uptake, in vivo glutamine synthetase (transferase) activity, and regulation of toxicity by ca2+, mg2+, cu2+ and ni2+ in the diazotrophic cyanobacterium nostoc calcicola bréb. have been completed. photoautotrophic growth of the cyanobacterium was extremely sensitive to both mercury compounds, ch3hg+ being 2.5 times more toxic than hg2+. although nh4+ uptake was 6 times more s ... | 1992 | 1375141 |
| a nitrate reductase gene of the cyanobacterium synechococcus pcc6301 inferred by heterologous hybridization, cloning and targeted mutagenesis. | dna probes from the narg gene of escherichia coli, which encodes the large polypeptide of respiratory nitrate reductase, show cross-hybridization at low stringency to a single region of the genome of the cyanobacterium synechococcus pcc6301. this segment of cyanobacterial dna was cloned as the insert of plasmid pdn1 and characterized. rna complementary to pdn1 was shown to be substantially more abundant in nitrate grown cells of synechococcus pcc6301 than in ammonium grown cells, thus parallelli ... | 1992 | 1378036 |
| identification of multiple rna polymerase sigma factor homologs in the cyanobacterium anabaena sp. strain pcc 7120: cloning, expression, and inactivation of the sigb and sigc genes. | the siga gene of anabaena sp. strain pcc 7120, encoding the principal rna polymerase sigma factor, and the complement of the rpod oligonucleotide (k. tanaka, t. shiina, and h. takahashi, science 242:1040-1042, 1988) were used as probes to isolate two genes, sigb and sigc, which encode two putative sigma factors exhibiting high degrees of similarity to siga, to hrda, -b, -c, and -d of streptomyces coelicolor, and to katf of escherichia coli. sigb and sigc code for polypeptides of 332 and 416 amin ... | 1992 | 1385387 |
| abscisic acid and its synthetic analog in relation to growth and nitrogenase activity of azotobacter chroococcum and nostoc muscorum. | the plant hormone abscisic acid as well as its synthetic analog lab 173711 significantly increased the nitrogenase activity of the bacterium azotobacter chroococcum and the cyanobacterium nostoc muscorum. the effect depended on the concentration of the substances (0.001-10 mg/l) and the age of the cultures. the biomass of the organisms was not significantly influenced. | 1992 | 1387101 |
| three new microcystins, cyclic heptapeptide hepatotoxins, from nostoc sp. strain 152. | three new cyclic heptapeptide hepatotoxins, [d-ser1,admadda5]microcystin-lr (1), [d-asp3,-admadda5]microcystin-lhar (2), and [admadda5,mser7]microcystin-lr (3), were isolated from the cyanobacterium (blue-green alga) nostoc sp. strain 152, together with four known microcystins, [admadda5]microcystin-lr (4), [admadda5]microcystin-lhar (5), [d-asp3,-admadda5]microcystin-lr (6), and [dmadda5]microcystin-lr (7). the structures of new microcystins were assigned on the basis of high-resolution fast at ... | 1992 | 1391612 |
| in vitro activation of dinitrogenase reductase from the cyanobacterium anabaena variabilis (atcc 29413). | nitrogenase of the heterocystous cyanobacterium anabaena variabilis was inactivated in vivo (s. reich, h. almon, and p. böger, fems microbiol. lett. 34:53-56, 1986). partially purified and modified (inactivated) dinitrogenase reductase (fe-protein) of such cells was reactivated by isolated membrane fractions of a. variabilis or of rhodospirillum rubrum, and acetylene reduction was measured. reactivation requires atp, mg2+, and mn2+. the activating principle is localized in the heterocyst and was ... | 1992 | 1400166 |
| isolation of arginine auxotrophs, cloning by mutant complementation, and sequence analysis of the argc gene from the cyanobacterium anabaena species pcc 7120. | arginine auxotrophs of the dinitrogen-fixing cyanobacterium anabaena species strain pcc 7120 were isolated after ultraviolet light mutagenesis and penicillin enrichment. two of these auxotrophs were complemented by a cosmid gene library of the wild-type strain established in escherichia coli that was transferred en masse to the mutants by conjugation. the gene complementing one of those mutants was found to complement an e. coli argc mutant. sequencing analysis of the gene showed that it encodes ... | 1992 | 1406250 |
| complementation of a red-light-indifferent cyanobacterial mutant. | many cyanobacteria alter their phycobilisome composition in response to changes in light wavelength in a process termed complementary chromatic adaptation. mutant strains fdr1 and fdr2 of the filamentous cyanobacterium fremyella diplosiphon are characterized by aberrant chromatic adaptation. instead of adjusting to different wavelengths of light, fdr1 and fdr2 behave as if they are always in green light; they do not respond to red light. we have previously reported complementation of fdr1 by con ... | 1992 | 1409650 |
| unsaturation of fatty acids in membrane lipids enhances tolerance of the cyanobacterium synechocystis pcc6803 to low-temperature photoinhibition. | effect of the unsaturation of fatty acids in the glycerolipids of thylakoid membranes on low-temperature photoinhibition of photosynthesis was studied by mutation and transformation of the cyanobacterium synechocystis pcc6803. when grown at 34 degrees c, the wild type contained mono-, di-, and triunsaturated lipids; a mutant, designated fad6, contained mono- and diunsaturated lipids; and a transformant of fad6, with a disrupted gene for desaturation and designated fad6/desa::kmr, contained only ... | 1992 | 1409727 |
| dna sequence and analysis of a cryptic 4.2-kb plasmid from the filamentous cyanobacterium, plectonema sp. strain pcc 6402. | the 4194-bp plasmid, prf1, from plectonema sp. strain pcc 6402 was completely sequenced and analyzed. seven potential open reading frames were identified. the predicted amino acid sequence of open reading frame c (orf c) had identities of 34, 29, and 25% with rep b from the staphylococcus aureus plasmid, pub110; rep from the bacillus amyloliquefaciens plasmid, pftb14; and protein a from the s. aureus plasmid, pc194, respectively. a 75-amino-acid region conserved in these proteins (rep b, rep, an ... | 1992 | 1409974 |
| ferredoxin-nadp+ oxidoreductase of c. paradoxa nucleus encoded, but cyanobacterial gene transfer from symbiont to host, an evolutionary mechanism originating new species. | the nucleus encoded cyanoplast ("cyanellar") ferredoxin-nadp + oxidoreductase (fnr) of cyanophora paradoxa, characterized by an n-terminal amino acid sequence, is compared with homologous sequences of other photoautotrophic organisms. the high degree of similarity to the cyanobacterial sequences indicates a cyanobacterial origin. this could be a first direct demonstration of an intertaxonic combination: a gene transfer from an original endocytobiont (cyanobacterium) to the nucleus of its host, o ... | 1992 | 1418237 |
| role of the carboxy terminus of polypeptide d1 in the assembly of a functional water-oxidizing manganese cluster in photosystem ii of the cyanobacterium synechocystis sp. pcc 6803: assembly requires a free carboxyl group at c-terminal position 344. | the d1 polypeptide of the photosystem ii (psii) reaction center is synthesized as a precursor polypeptide which is posttranslationally processed at the carboxy terminus. it has been shown in spinach that such processing removes nine amino acids, leaving ala344 as the c-terminal residue [takahashi, m., shiraishi, t., & asada, k. (1988) febs lett. 240, 6-8; takahashi, y., nakane, h., kojima, h., & satoh, k. (1990) plant cell physiol. 31, 273-280]. we show here that processing on the carboxy side o ... | 1992 | 1420199 |
| cloning and characterization of the secy gene from the cyanobacterium synechococcus pcc7942. | the secy gene product is an essential component of the escherichia coli cytoplasmic membrane, which mediates the protein translocation across the membrane. we found a gene homologous to secy in the genome of the cyanobacterium synechococcus pcc7942. the deduced amino acid sequence, 439 amino acids long, shows 43% homology with that of the e. coli secy. the hydrophobic profile suggests that the synechococcus secy protein is an integral membrane protein containing ten membrane-spanning segments, w ... | 1992 | 1420358 |
| cloning and sequencing of the petbd operon from the cyanobacterium synechococcus sp. pcc 7002. | the genes encoding the photosynthetic cytochrome b6 (petb) and subunit 4 (petd) have been cloned and sequenced from the unicellular, photoheterotrophic, transformable cyanobacterium synechococcus sp. pcc 7002, formerly designated agmenellum quadruplicatum. the gene arrangement was found to be similar to that reported in the cyanobacterium nostoc pcc 7906. the dna and derived protein sequences were compared to chloroplast and the other cyanobacterial sequences. by pulsed-field electrophoresis, th ... | 1992 | 1421151 |
| nucleotide sequence of a metallothionein gene of the thermophilic cyanobacterium synechococcus vulcanus. | 1992 | 1421159 | |
| thermally-induced delayed fluorescence of photosystem i and ii chlorophyll in thermophilic cyanobacterium synechococcus elongatus. | stationary delayed fluorescence (df) of chlorophyll in isolated membrane preparations from thermophilic cyanobacterium synechococcus elongatus was investigated as a function of temperature. two peaks at different temperatures were observed. the low-temperature peak (54-60 degrees c) coincided with the main maximum of the thermally-induced delayed fluorescence of chlorophyll in intact cells and psii-particles with active oxygen-evolving system. the high-temperature peak (78 degrees c) coincided w ... | 1992 | 1426973 |
| excitation energy transfer from phycocyanin to chlorophyll in an apca-defective mutant of synechocystis sp. pcc 6803. | a greenish mutant of the normally blue-green cyanobacterium synechocystis sp. pcc 6803, designated uv6p, has been isolated and characterized. uv6p possesses functional photosystems i and ii (psi and psii) but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. the mutation responsible for the uv6p phenotype has been identified; it is a base substitution which results in the creation of a termination codon wi ... | 1992 | 1429645 |
| structure determination and toxicity of a new microcystin from microcystis aeruginosa strain 205. | a new hepatotoxic microcystin was isolated from the cyanobacterium microcystis aeruginosa strain 205. its structure was found to be [dha7]microcystin-rr as determined by amino acid analysis, mass spectrometry and 1h nmr spectroscopy. ld50 value (i.p. mouse) of this toxin was 180 micrograms/kg. the 48 hr lethal concentration (48-hr-lc50) of the toxin for larvae of the yellow fever mosquito, aedes aegypti, was 14.9 micrograms/ml. | 1992 | 1440646 |
| identification of arginyl residues involved in the binding of ferredoxin-nadp+ reductase from anabaena sp. pcc 7119 to its substrates. | ferredoxin-nadp+ reductase from the cyanobacterium anabaena sp. pcc 7119 was chemically modified by the alpha-dicarbonyl reagent phenylglyoxal. the studies of the inactivation by this compound, which is specific for arginyl residues, of both the diaphorase and nadph-cytochrome c reductase activities, characteristic of the enzyme, are indicative of the involvement of at least one group of this kind in the binding site of nadp+ and a second one implicated in the interaction with ferredoxin. after ... | 1992 | 1444467 |
| effects of mutations at residue 309 of the large subunit of ribulosebisphosphate carboxylase from synechococcus pcc 6301. | previous studies [g. s. hudson et al. (1989) j. biol. chem. 265, 808-814] showed that the faster turnover rates and lower affinities for co2 of ribulosebisphosphate carboxylase/oxygenases from c4 plants, compared to c3 and c3/c4 plants, were specified by the chloroplast-encoded large subunits. in pairs of closely related c3 and c4 species from three genera, these kinetic changes were accompanied by only three to six amino acid residue substitutions, depending on the genus. none of these substitu ... | 1992 | 1444469 |
| purification and properties of urease from the cyanobacterium anabaena cylindrica. | a purification procedure has been developed by which urease activity in extracts from the cyanobacterium anabaena cylindrica was enriched 500-fold. the procedure involves mgso4 precipitation at 55 degrees c and chromatography on hydroxylapatite and diethylaminoethyl sephadex. its molecular weight was measured by sedimentation equilibrium in an airfuge to be 197,000 +/- 2000 with an estimated subunit molecular weight of 32,000 as determined by polyacrylamide gel electrophoresis. the ph- and tempe ... | 1992 | 1445371 |
| energy transfer (deazaflavin-->fadh2) and electron transfer (fadh2-->t <> t) kinetics in anacystis nidulans photolyase. | dna photolyases catalyze the photocycloreversion of cyclobutane pyrimidine dimers. the enzyme from the cyanobacterium anacystis nidulans contains two chromophores, 1,5-dihydroflavin adenine dinucleotide (fadh2) and 7,8-didemethyl-8-hydroxy-5-deazariboflavin (8-hdf). the photophysical/photochemical reactions leading to dna repair were investigated by using time-resolved and steady-state fluorescence spectroscopy. it was found that the excited singlet state of 8-hdf transfers energy to fadh2 at a ... | 1992 | 1445863 |
| site-directed mutagenesis of the cpa-1 protein of photosystem ii: alteration of the basic residue pair 384,385r to 384,385g leads to a defect associated with the oxygen-evolving complex. | the psbb gene encodes the intrinsic chlorophyll-a binding protein cpa-1 (cp-47), a component of photosystem ii in higher plants, algae, and cyanobacteria. oligonucleotide-directed mutagenesis was used to introduce mutations into a segment of the psbb gene encoding the large extrinsic loop region of cpa-1 in the cyanobacterium synechocystis sp. pcc 6803. altered psbb genes were introduced into a mutant recipient strain (del-1) of synechocystis in which the genomic psbb gene had been partially del ... | 1992 | 1445882 |
| structures of three new homotyrosine-containing microcystins and a new homophenylalanine variant from anabaena sp. strain 66. | a hepatotoxic strain of cyanobacterium anabaena sp. 66 was isolated from a hepatotoxic water bloom sample in lake kiikkara, finland. four cyclic heptapeptide hepatotoxins were isolated and purified by hplc from cultured cells of this organism. the structures of three new homotyrosine (hty) containing toxins, [dha7]microcystin-htyr (dha = dehydroalanine) (1), [d-asp3,dha7]microcystin-htyr (2), and [l-ser7]microcystin-htyr (3), were assigned, based upon amino acid analyses using both a waters pico ... | 1992 | 1446006 |
| beyond the barcoo--probable human tropical cyanobacterial poisoning in outback australia. | to determine the cause of a disease known variously as "barcoo fever, barcoo spews, barcoo sickness", or simply "the barcoo", once prevalent in outback northern and central australia. | 1992 | 1454012 |
| effects of chemical modification of anabaena flavodoxin and ferredoxin-nadp+ reductase on the kinetics of interprotein electron transfer reactions. | the influence of chemical modification of arginine residues (using phenylglyoxal) in ferredoxin-nadp+ reductase (fnr), and of carboxyl groups (using glycine ethyl ester) in flavodoxin (fld), on the kinetics of electron transfer between fnr and fld, and between ferredoxin (fd) and fnr, was examined using laser flash photolysis methods. all proteins were obtained from the cyanobacterium anabaena pcc7119. reduction by laser-generated 5-deazariboflavin semiquinone of the fad moiety of phenylglyoxal- ... | 1992 | 1459139 |
| structure and expression of a cyanobacterial ilvc gene encoding acetohydroxyacid isomeroreductase. | acetohydroxyacid isomeroreductase (ahair) is the shared second enzyme in the biosynthetic pathways leading to isoleucine and valine. ahair is encoded by the ilvc gene in bacteria. a 1,544-bp fragment of genomic dna containing the ilvc gene was cloned from the cyanobacterium synechocystis sp. strain pcc 6803, and the complete nucleotide sequence was determined. the identity of the gene was established by comparison of the nucleotide and derived peptide sequences with those of other ilvc genes. th ... | 1992 | 1459938 |
| presence of an n-terminal presequence in the psai protein of the photosystem i complex in the filamentous cyanobacterium anabaena variabilis atcc 29413. | the psai gene encoding the 5.2 kda protein component (psai) of the photosystem i complex was cloned from the cyanobacterium anabaena 29413. the gene is present in single copy in this cyanobacterial genome. the nucleotide sequence of a 500 bp region of the cloned dna revealed the presence of an open reading frame encoding a 46 amino acid long polypeptide. the n-terminal 11 residues are absent in the mature polypeptide and thus represents the first identified cleavable presequence on the psai prot ... | 1992 | 1463834 |
| identification of a second psac gene in the cyanobacterium synechocystis sp. pcc6803. | the psac gene encodes the 9 kda protein subunit of photosystem i that carries the iron-sulfur centers fa and fb. the paper describes the sequence and transcription analysis of a second psac gene (psac2) from synechocystis sp. pcc6803. thepsac2 gene is transcribed into an abundant monocistronic mrna. the deduced amino acid sequence of psi-c2 is very similar to the protein sequences from two other cyanobacteria (synechococcus sp. pcc7002 and nostoc sp. pcc8009). in contrast, the recently isolated ... | 1992 | 1463835 |
| cloning and transcription analysis of the ndh(a-i-g-e) gene cluster and the ndhd gene of the cyanobacterium synechocystis sp. pcc6803. | the plastid dna of higher plants contains eleven reading frames that are homologous to subunits of the mitochondrial nadh-ubiquinone oxidoreductase (complex i). the genes are expressed, but a plastid nad(p)h dehydrogenase has not yet been isolated and the function of the enzyme in plastid metabolism is unknown. cyanobacteria also contain a nadh dehydrogenase that is homologous to the mitochondrial complex i. the enzyme is sensitive to rotenone and is located on the cytoplasmic and the thylakoid ... | 1992 | 1463844 |
| primary structure of the synechococcus pcc 7942 paps reductase gene. | the structural gene encoding a thioredoxin-dependent 5'-phosphoadenylyl sulphate (paps) reductase (ec 1.8.4.-) from cyanobacterium synechococcus pcc 7942 ('anacystis nidulans') was detected by heterologous hybridization with the cysh gene from escherichia coli k12. the cyanobacterial gene (further called par gene) comprised 696 nt which are 57.8% homologous to the enterobacterial gene. the putative open reading frame encoded a polypeptide consisting of 232 amino acid residues (deduced molecular ... | 1992 | 1463852 |
| restoration of the wild-type locus in an rubp carboxylase/oxygenase mutant of synechocystis pcc 6803 via targeted gene recombination. | the interaction between homologous dna sequences, distant from each other in the chromosome, was examined in the cyanobacterium synechocystis pcc 6803. most of the rbcl gene encoding the large subunit of ribulose bisphosphate carboxylase/oxygenase (rubisco) was duplicated in the genome by a targeted insertion of a 3'-truncated gene copy into the psb a-i locus. both rbcl genes, in the psb a-i region and at the rbc locus, were non-functional; the former due to the 3' truncation, and the latter due ... | 1992 | 1465099 |
| purification, characterization and function of dihydrolipoamide dehydrogenase from the cyanobacterium anabaena sp. strain p.c.c. 7119. | a dihydrolipoamide dehydrogenase (dihydrolipoamide: nad+ oxidoreductase, ec 1.8.1.4) (dld) has been found in the soluble fraction of cells of both unicellular (synechococcus sp. strain p.c.c. 6301) and filamentous (calothrix sp. strain p.c.c. 7601 and anabaena sp. strain p.c.c. 7119) cyanobacteria. dld from anabaena sp. was purified 3000-fold to electrophoretic homogeneity. the purified enzyme exhibited a specific activity of 190 units/mg and was characterized as a dimeric fad-containing protein ... | 1992 | 1471997 |
| two new l-serine variants of microcystins-lr and -rr from anabaena sp. strains 202 a1 and 202 a2. | two new microcystins, [l-ser7]microcystin-lr (1) and [l-ser7]microcystin-rr (2), were isolated from a filamentous fresh water cyanobacterium (blue-green alga), anabaena sp. strain 202 a1, along with the two major toxins, [dha7]microcystin-lr (3) and [dha7]microcystin-rr (4) and their minor components the d-asp variants [d-asp3,dha7]microcystin-lr (5) and [d-asp3,dha7]microcystin-rr (6). anabaena sp. strain 202 a1 also produced another new toxin, whose structure is tentatively proposed as [d-asp3 ... | 1992 | 1485340 |
| the cyanobacterium oscillatoria erythraea--a potential source of toxin in the ciguatera food-chain. | a compound lethal to mice (i.p.) was extracted from samples of oscillatoria erythraea, four species of mollusc and one species of molluscivorous teleost collected from the south-east coast of queensland, australia, during and shortly after o. erythraea blooms. the compound was chemically indistinguishable from ciguatoxin (ctx) on the basis of solvent extraction and partitioning and silicic acid chromatography. residues derived from toxic samples elicited signs of intoxication, death and histopat ... | 1992 | 1493884 |
| phycocyanin alpha-subunit phycocyanobilin lyase. | phycobiliproteins, unlike other light-harvesting proteins involved in photosynthesis, bear covalently attached chromophores. the bilin chromophores are attached through thioether bonds to cysteine residues. the cyanobacterium synechococcus sp. pcc 7002 has eight distinct bilin attachment sites on seven polypeptides, all of which carry the same chromophore, phycocyanobilin. when two genes in the phycocyanin operon of this organism, cpce and cpcf, are inactivated by insertion, together or separate ... | 1992 | 1495995 |
| mutations in the d1 subunit of photosystem ii distinguish between quinone and herbicide binding sites. | the structure-activity relationships of the plastoquinone qb binding domain in the d1 subunit of photosystem ii (psii) were investigated by characterization of mutations introduced in the d1 protein. eight novel point mutations in the gene psba, which encodes d1, were generated in the cyanobacterium synechocystis pcc6803 by site-specific mutagenesis in vitro. the effects of the resulting modifications in d1 on electron transfer in psii and on herbicide binding were analyzed. the results extend t ... | 1992 | 1498597 |
| evidence for an ultraviolet sunscreen role of the extracellular pigment scytonemin in the terrestrial cyanobacterium chlorogloeopsis sp. | the proposed photoprotective role of the uv-a absorbing, extracellular pigment scytonemin was studied in the terrestrial cyanobacterium chlorogloeopsis sp. strain o-89-cgs(1). uv-a (315-400 nm) caused growth delay, cell growth restarting only when scytonemin had accumulated in the extracellular envelopes. cultures with scytonemin were more resistant to photoinhibition of photosynthesis than cultures without scytonemin, the differential resistance being much greater to uv-a-caused photoinhibition ... | 1992 | 1508978 |
| oxygen yield and thermoluminescence characteristics of a cyanobacterium lacking the manganese-stabilizing protein of photosystem ii. | previous experiments have shown that a synechocystis sp. pcc 6803 mutant (delta psbo) lacking the extrinsic manganese-stabilizing protein (msp) exhibits impaired, but significant levels of h2o-splitting activity [burnap, r., & sherman, l.a. (1991) biochemistry 30, 440-446]. [14c]dcmu-binding experiments now show that the number and affinity of dcmu-binding sites (normalized to chlorophyll) are equivalent in delta psbo and the wild type, suggesting equal concentrations of assembled reaction cente ... | 1992 | 1510930 |
| the complete nucleotide sequence of the gene (rpod1) encoding the principal sigma factor of the rna polymerase from the cyanobacterium synechococcus sp. strain pcc7942. | the complete nucleotide sequence of rpod1 gene from synechococcus pcc7942 has been determined. the nucleotide data have indicated the presence of an open reading frame of 1155 base pairs encoding a polypeptide which shares the framework structure for principal sigma factors of eubacterial strains. | 1992 | 1511015 |
| molecular characterization of the genes encoding acetohydroxy acid synthase in the cyanobacterium spirulina platensis. | the enzyme acetohydroxy acid synthase (ahs), which catalyses the first common step in the biosynthesis of isoleucine, leucine and valine, has been demonstrated to be present in spirulina platensis in two isoenzymic forms. the complete nucleotide sequences of the genes ilvx and ilvw encoding these two enzymes have been determined. sequence analysis revealed the presence of two open reading frames, of 1836 and 1737 nucleotides for ilvx and ilvw, respectively. the predicted amino acid sequences of ... | 1992 | 1512571 |
| cytotoxicity of cyanobacterium microcystis aeruginosa. | cytotoxic effects of crude extracts and fractions of the purification steps towards microcystin-lr (mcyst-lr) were investigated in vitro. cytotoxicity was evaluated by measure of lactate dehydrogenase liberation of chang liver cells and by hemolysis. crude extracts of strain pcc 7806 damaged the cells within a few minutes. in contrast, mcyst-lr did not show any detectable cytotoxic effects. the cytotoxic activity could be related to a heat-labile substance with a molecular weight of about 30,000 ... | 1992 | 1519410 |
| characterization of a light-regulated gene encoding a new phycoerythrin-associated linker protein from the cyanobacterium fremyella diplosiphon. | cyanobacteria utilize multimeric protein complexes, the phycobilisomes, as their major light-harvesting antennae. associated with the chromophorylated phycobiliproteins in these complexes are nonpigmented proteins, designated linker proteins. these linker proteins are believed to mediate assembly of the phycobilisome and energy transfer to the photosynthetic reaction center. we cloned and sequenced a gene, cpee, encoding a previously uncharacterized linker protein which is expressed in green lig ... | 1992 | 1522075 |
| [sequence and primary structure analysis of specific dna fragment related to pollen fertility in radish chloroplast genome]. | nucleotide sequence of a radish chloroplast bafhi-ecori fragment (zl1) derived from b21, which is related to cytoplasmic male sterility and also found in radish 401b retaining line, has been determined. the results show that this fragment is 474bp in length, and is rich in at base components. the nucleotide sequence of zl1 has 96.6% homology as compared with the corresponding sequence of tobacco which is located at the positions from 142330 to 142803 in ira and from 100199 to 99726 in irb in the ... | 1992 | 1524844 |
| the homologies of gas vesicle proteins. | in addition to gvpa, the main structural protein, an sds-soluble protein has been found in gas vesicles isolated from six different genera of cyanobacteria. n-terminal sequence analysis of the first 30 to 60 residues of the gel-purified proteins showed that they were homologous to gvpc, a protein that strengthens the gas vesicle in anabaena flos-aquae. the proteins from some of the organisms showed rather low homology, however, and this may explain why the genes that encode them have not been fo ... | 1992 | 1527496 |
| an iron stress operon involved in photosynthetic electron transport in the marine cyanobacterium synechococcus sp. pcc 7002. | the iron-stress-induced genes isia and isib have been cloned and sequenced from the marine unicellular cyanobacterium synechococcus sp. pcc 7002. these genes code for a photosystem ii chlorophyll-binding protein and flavodoxin respectively. the genes form a dicistronic operon that is transcriptionally activated under iron-stress conditions to produce an abundant monocistronic message containing isia and a much less abundant dicistronic message that also contains isib. the arrangement of these ge ... | 1992 | 1527503 |
| characterization of damage to photosystems i and ii in a cyanobacterium lacking detectable iron superoxide dismutase activity. | the enzyme superoxide dismutase is ubiquitous in aerobic organisms where it plays a major role in alleviating oxygen-radical toxicity. an insertion mutation introduced into the iron superoxide dismutase locus (designated sodb) of the cyanobacterium synechococcus sp. pcc 7942 created a mutant strain devoid of detectable iron superoxide dismutase activity. both wild-type and mutant strains exhibited similar photosynthetic activity and viability when grown with 17 mumol.m-2.s-1 illumination in liqu ... | 1992 | 1528884 |
| nickel effects on phosphate uptake, alkaline phosphatase, and atpase of a cyanobacterium. | 1992 | 1533803 | |
| purification, characterization and function of bacterioferritin from the cyanobacterium synechocystis p.c.c. 6803. | storage and buffering of iron is achieved by a class of proteins, the ferritins, widely distributed throughout the living kingdoms. all ferritins have in common their three-dimensional structure and their ability to store large amounts of iron in their central cavity. however, eukaryotic ferritins from plants and animals and bacterioferritins have no sequence similarity, and besides non-haem iron bacterioferritins contain haem residues whereas eukaryotic ferritins do not. in this paper we report ... | 1992 | 1536655 |
| heat shock hsp70 protein is chloroplast-encoded in the chromophytic alga pavlova lutherii. | heat shock proteins are ubiquitous and highly conserved. recently they have become implicated in the import of proteins into organelles. all the heat shock genes characterized to date, however, are known or assumed to be encoded in the nuclear genome even if the corresponding protein can be localised in the mitochondrion or chloroplast. in contrast, we identify here an hsp70 gene in the unicellular chromophytic alga pavlova lutherii which is located on the chloroplast genome. localisation of thi ... | 1992 | 1536924 |
| molecular cloning and expression in escherichia coli of a cyanobacterial gene coding for phytoene synthase, a carotenoid biosynthesis enzyme. | the first committed step in the biosynthetic pathway of carotenoids in plants and algae is the conversion of geranylgeranyl pyrophosphate (ggpp) to prephytoene pyrophosphate (pppp), which is converted to phytoene. we have cloned the gene pys that encodes the enzyme phytoene synthase in the cyanobacterium synechococcus pcc7942. the co-expression of pys in cells of escherichia coli together with the gene crte from erwinia uredovora, which encodes geranylgeranyl pyrophosphate synthase, resulted in ... | 1992 | 1537409 |
| serine-376 contributes to the binding of substrate by ribulose-bisphosphate carboxylase/oxygenase from anacystis nidulans. | site-directed mutagenesis was used to change ser376 in the active site of ribulose-1,5-bisphosphate carboxylase/oxygenase from the cyanobacterium anacystis nidulans to cys, thr, or ala. when expressed in escherichia coli and purified, the mutant enzymes exhibited carboxylase activities that were reduced by 99% or more with respect to the activity of the wild-type enzyme. the km values for ribulose bisphosphate at ph 8.0, 30 degrees c, were elevated from 46 microm for wild-type enzyme to 287, 978 ... | 1992 | 1540586 |
| the psac genes of synechococcus sp. pcc7002 and cyanophora paradoxa: cloning and sequence analysis. | the psac genes of the cyanobacterium, synechococcus sp. pcc7002, and of the cyanelle genome of the phylogenetically ambiguous biflagellate, cyanophora paradoxa, were cloned, mapped and sequenced. the psac proteins of both species exhibit high degrees (approx. 95%) of sequence similarity to the psac proteins of other cyanobacteria as well as the chloroplast-encoded proteins of green algae and higher plants. the synechococcus sp. pcc7002 psac gene is transcribed as a monocistronic mrna of approx. ... | 1992 | 1551590 |
| identification of replication and stability functions in the complete nucleotide sequence of plasmid puh24 from the cyanobacterium synechococcus sp. pcc 7942. | the complete nucleotide sequence is presented for puh24, the small plasmid of synechococcus sp. pcc 7942. puh24 consists of 7835bp and has a g + c content of 59%. the distribution of translation start and stop codons in the sequence allows 36 open reading frames that potentially encode polypeptides of 50 or more amino acids. we postulate that eight of these open reading frames are actual coding sequences. a region has been identified, by experiment, that contains two functions, designated pmaa a ... | 1992 | 1552863 |
| clustering of genes involved in nitrate assimilation in the cyanobacterium synechococcus. | a region of the genome of the cyanobacterium synechococcus r2, that bears a cluster of genes involved in nitrate assimilation, has been cloned and the relative positions of some of the genes in the region have been determined. mutations generated by insertion of an antibiotic-resistance gene cassette into the gene encoding nitrite reductase are associated with reduced expression of nitrate reductase; cotranscription of nitrate assimilation genes in the cluster is inferred from this finding. | 1992 | 1552905 |
| nitrate transport in the cyanobacterium anacystis nidulans r2. kinetic and energetic aspects. | nitrate transport has been studied in the cyanobacterium anacystis nidulans r2 by monitoring intracellular nitrate accumulation in intact cells of the mutant strain fm6, which lacks nitrate reductase activity and is therefore unable to reduce the transported nitrate. kinetic analysis of nitrate transport as a function of external nitrate concentration revealed apparent substrate inhibition, with a peak velocity at 20-25 microm-nitrate. a ks (no3-) of 1 microm was calculated. nitrate transport ex ... | 1992 | 1554347 |
| molecular characterization of ferredoxin-nadp+ oxidoreductase in cyanobacteria: cloning and sequence of the peth gene of synechococcus sp. pcc 7002 and studies on the gene product. | the peth gene encoding ferredoxin-nadp+ oxidoreductase (fnr) was cloned and sequenced from the cyanobacterium synechococcus sp. pcc 7002. the deduced amino acid sequence of the fnr protein (402 amino acids) is approximately 110 amino acids longer at the n-terminus than fnr proteins which have been characterized from other cyanobacteria. n-terminal amino acid sequence analysis of the protein confirms the assigned translational start codon and shows that the initiator methionine is not removed. ma ... | 1992 | 1554697 |
| activities of two dissimilar thioredoxins from the cyanobacterium anabaena sp. strain pcc 7120. | thioredoxin is a small redox protein that functions as a reducing agent and modulator of enzyme activity. a gene for an unusual thioredoxin was previously isolated from the cyanobacterium anabaena sp. strain pcc 7120 and cloned and expressed in escherichia coli. however, the protein could not be detected in anabaena cells (j. alam, s. curtis, f. k. gleason, m. gerami-nejad, and j. a. fuchs, j. bacteriol. 171:162-171, 1989). polyclonal antibodies to the atypical thioredoxin were prepared, and the ... | 1992 | 1556078 |
| nucleotide sequences of the psaa and psab genes encoding the photosystem i core proteins from the thermophilic cyanobacterium synechococcus vulcanus. | 1992 | 1558952 | |
| nucleotide sequence and expression of the gene for the 9 kda fa/fb component of photosystem i from the cyanobacterium anabaena sp. pcc7120. | the nucleotide sequence of an 813 bp ssp i-hinc ii fragment containing the psac gene from anabaena sp. pcc 7120 is reported. the gene encodes a polypeptide of 81 amino acids, has a single transcript of size approximately 480 nucleotides and a single startpoint of transcription. it is flanked by a ribosome binding site on the 5' end and a potential transcription terminator on the 3' end. comparison of the amino acid sequences of the psac gene product from sixteen organisms shows that cyanobacteri ... | 1992 | 1558954 |
| differential effect of ultraviolet-b radiation on certain metabolic processes in a chromatically adapting nostoc. | the impact of uv-b radiation on growth, pigmentation and certain physiological processes has been studied in a n2-fixing chromatically adapting cyanobacterium, nostoc spongiaeforme. a brownish form (phycoerythrin rich) was found to be more tolerant to uv-b than the blue-green (phycocyanin rich) form of n. spongiaeforme. continuous exposure to uv-b (5.5 w m-2) for 90 min caused complete killing of the blue-green strain whereas the brown strain showed complete loss of survival after 180 min. pigme ... | 1992 | 1561238 |
| effects of acephate on n2-fixing cyanobacterium anabaena pcc 7119. | 1992 | 1568067 | |
| glutamyl-trna reductase from escherichia coli and synechocystis 6803. gene structure and expression. | in the cyanobacterium synechocystis sp. pcc 6803 and in the enterobacterium escherichia coli delta-amino-levulinic acid (ala) is formed from glutamyl-trna by the sequential action of two enzymes, glutamyl-trna reductase (glutr) and glutamate-1-semialdehyde aminotransferase. e. coli has two glutr proteins with sizes of 45 kda (glutr45) and 85 kda (glutr85) (jahn, d., michelsen, u., and söll, d. (1991) j. biol. chem. 266, 2542-2548). the hema gene, isolated from e. coli and several other eubacteri ... | 1992 | 1569081 |
| coding sequence of a heterocyst ferredoxin gene (fdxh) isolated from the nitrogen-fixing cyanobacterium calothrix sp. pcc 7601. | 1992 | 1581559 | |
| purification and characterization of the ferredoxin-glutamate synthase from the unicellular cyanobacterium synechococcus sp. pcc 6301. | ferredoxin-glutamate synthase from the unicellular cyanobacterium synechococcus sp. pcc 6301 has been purified using, as main steps, ethanol fractionation in the presence of high ionic strength, ion-exchange chromatography and ferredoxin-sepharose affinity chromatography. the overall process yielded an homogeneous enzyme with a specific activity of 30 u/mg protein, after a purification of 2800-fold with a recovery of 43%. the molecular mass of the native protein was 156 kda, as calculated from i ... | 1992 | 1587284 |
| identification, characterization and sequence analysis of the gene encoding phosphoenolpyruvate carboxylase in anabaena sp. pcc 7120. | the gene (ppc) encoding phosphoenolpyruvate carboxylase (pepcase) in the cyanobacterium anabaena sp. pcc 7120 has been isolated, characterized and its nucleotide sequence determined. heterologous hybridization using the synechococcus sp. pcc 7942 ppc gene as a probe of an anabaena genomic dna library identified an 8.2 kb hindiii dna fragment that contained a 3.08 kb open reading frame encoding the cyanobacterial pepcase. deletion analysis of the 8.2 kb dna fragment was used to determine sequence ... | 1992 | 1588304 |
| construction of insertion mutants of synechocystis sp. pcc 6803: evidence for an essential function of subunit iv of the cytochrome b6/f complex. | the gene encoding subunit iv of the cytochrome b6/f complex (petd) has been isolated from a genomic library of the unicellular cyanobacterium synechocystis sp. pcc 6803. the coding region consists of 480 nucleotides and can code for a polypeptide with a molecular weight of 17.5 kda. the deduced amino acid sequence shows high identity with the corresponding sequences of both the photoautotrophic prokaryote nostoc sp. pcc 7906 as well as of lower and higher photoautotrophic eukaryotes (e.g. chlore ... | 1992 | 1590707 |
| transcriptional and posttranscriptional components of psba response to high light intensity in synechococcus sp. strain pcc 7942. | the psba genes, which encode the d1 protein of photosystem ii, constitute a multigene family in the cyanobacterium synechococcus sp. strain pcc 7942. levels of messages from the three psba genes change rapidly when cells are shifted from low-light to high-light conditions: the psbai message level drops, whereas psbaii and psbaiii message levels increase dramatically. we examined the potential contributions of transcriptional and posttranscriptional processes in these high-light responses by subj ... | 1992 | 1592828 |
| molecular cloning and sequencing of the beta-isopropylmalate dehydrogenase gene from the cyanobacterium spirulina platensis. | the gene for beta-isopropylmalate dehydrogenase (ec 1.1.1.85) of spirulina platensis (leub) was cloned from a lambda embl3 genomic library by heterologous hybridization using the nostoc ucd 7801 leub gene as a probe. the sequence of the entire leub coding region was determined as well as 645 bp of 5' flanking region and 956 bp of 3' flanking region. dna sequencing revealed an open reading frame of 1065 nucleotides capable of encoding a polypeptide of 355 amino acids. homologies between the amino ... | 1992 | 1593261 |
| isolation and identification of restriction endonuclease, seli from a cyanobacterium, synechococcus elongatus. | 1992 | 1598226 | |
| metabolism of phenanthrene by the marine cyanobacterium agmenellum quadruplicatum pr-6. | under photoautotrophic growth conditions, the marine cyanobacterium agmenellum quadruplicatum pr-6 metabolized phenanthrene to form trans-9,10-dihydroxy-9,10-dihydrophenanthrene (phenanthrene trans-9,10-dihydrodiol) and 1-methoxyphenanthrene as the major ethyl acetate-extractable metabolites. small amounts of phenanthrols were also formed. the metabolites were purified by high-pressure liquid chromatography and identified from their uv, infrared, mass, and proton magnetic resonance spectral prop ... | 1992 | 1599252 |
| evidence for an nih shift in oxidation of naphthalene by the marine cyanobacterium oscillatoria sp. strain jcm. | the marine cyanobacterium oscillatoria sp. strain jcm oxidized naphthalene predominantly to 1-naphthol. experiments with [1-2h]naphthalene and [2-2h]naphthalene indicated that 1-naphthol was formed with 68 and 74% retention of deuterium, respectively. no significant isotope effect was observed when the organism was incubated with a 1:1 mixture of naphthalene and [2h8]naphthalene. the results indicate that 1-naphthol is formed through a naphthalene 1,2-oxide intermediate, which rearranges spontan ... | 1992 | 1599253 |
| the d1 protein of the photosystem ii reaction-centre complex accumulates in the absence of d2: analysis of a mutant of the cyanobacterium synechocystis sp. pcc 6803 lacking cytochrome b559. | the reaction center core of photosystem ii, a multiprotein membrane bound complex, is composed of a heterodimer of two proteins, d1 and d2. a random mutagenesis technique was used to isolate a photosystem ii deficient mutant, cp6t16, of the unicellular cyanobacterium, synechocystis sp. pcc 6803. nucleotide sequence analysis showed that the primary lesion in cp6t16 is an ochre mutation introducing a translational stop codon in the psbe gene, encoding the alpha-subunit of cytochrome b559, an integ ... | 1992 | 1602969 |
| the pata gene product, which contains a region similar to chey of escherichia coli, controls heterocyst pattern formation in the cyanobacterium anabaena 7120. | in anabaena 7120, heterocysts (cells specialized for nitrogen fixation) develop at the ends of filaments and at intervals within each filament. we have isolated a mutant anabaena strain that develops heterocysts mostly at the ends of filaments. this mutant, pat-1, grows poorly under nitrogen-fixing conditions. the wild-type gene that complements the mutation in pat-1, called pata, was cloned and sequenced. the predicted pata protein contains 379 amino acids distributed among three "domains" base ... | 1992 | 1608976 |
| myoglobin in a cyanobacterium. | myoglobin was found in the nitrogen-fixing cyanobacterium nostoc commune. this cyanobacterial myoglobin, referred to as cyanoglobin, was shown to be a soluble hemoprotein of 12.5 kilodaltons with an amino acid sequence that is related to that of myoglobins from two lower eukaryotes, the ciliated protozoa paramecium caudatum and tetrahymena pyriformis. cyanoglobin is encoded by the glbn gene, which is positioned between nifu and nifh-two genes essential for nitrogen fixation-in the genome of nost ... | 1992 | 1609281 |
| a hybrid ribulosebisphosphate carboxylase/oxygenase enzyme exhibiting a substantial increase in substrate specificity factor. | two hybrid ribulose-1,5 bisphosphate carboxylase/oxygenase (rubisco) enzymes were constructed using rubisco small subunit genes (rbcs) from two eucaryotic marine organisms, cylindrotheca sp. n1 and olisthodiscus luteus, cloned downstream of the rubisco large subunit gene (rbcl) of the cyanobacterium synechococcus pcc 6301. the expression products synthesized by escherichia coli jm107 (pvtac223 and panoli) were purified and examined by polyacrylamide gel electrophoresis and compared to the purifi ... | 1992 | 1610800 |
| the structure of photosystem i from the thermophilic cyanobacterium synechococcus sp. determined by electron microscopy of two-dimensional crystals. | the structure of the photosystem i (ps i) complex from the thermophilic cyanobacterium synechococcus sp. has been investigated by electron microscopy and image analysis of two-dimensional crystals. crystals were obtained from isolated ps i by removal of detergents with bio-beads. after negative staining, either single layers or two superimposed layers with a rotational different orientation were observed. the layers have a rectangular unit cell of 16.0 x 15.0 nm, which contains two ps i monomers ... | 1992 | 1610871 |
| purification and characterization of the photosystem i complex from the filamentous cyanobacterium anabaena variabilis atcc 29413. | a photoactive photosystem i complex has been purified from the filamentous, nitrogen-fixing cyanobacterium anabaena variabilis atcc 29413. cells were broken using glass beads, and the membrane fraction was solubilized with beta-dodecyl maltoside followed by two rounds of fast protein liquid chromatography on anion exchange columns. the polypeptide composition of the isolated complex was determined by sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis and n-terminal amino acid sequenc ... | 1992 | 1618755 |
| cloning and expression of the cryivd gene of bacillus thuringiensis subsp. israelensis in the cyanobacterium agmenellum quadruplicatum pr-6 and its resulting larvicidal activity. | a mosquitocidal cyanobacterium has been developed by introducing the mosquito-toxic cryivd gene from bacillus thuringiensis subsp. israelensis into the unicellular cyanobacterium agmenellum quadruplicatum pr-6 (synechococcus sp. strain pcc 7002). the cryivd gene was introduced into the cyanobacterium on a derivative of the pr-6 expression vector paqe19 delta sal in which the cryivd gene was translationally fused to the initial coding sequence of the highly expressed pr-6 cpcb gene. coomassie blu ... | 1992 | 1622235 |
| localization and distribution of hopanoids in membrane systems of the cyanobacterium synechocystis pcc 6714. | intracellular localization of triterpenic membrane stabilizers of the hopane series is described for the first time for a cyanobacterium. in synechocystis pcc 6714, a bacteriohopanetetrol derivative (main compound) and diplopterol were detected in cell wall (cw) and thylakoid membrane (tm). both hopanoids were enriched 4.5-fold and 9.0-fold in cw and outer membrane (om) fractions, respectively, compared to tms. | 1992 | 1624128 |
| chlorosis induced by nutrient deprivation in synechococcus sp. strain pcc 7942: not all bleaching is the same. | cell coloration changes from normal blue-green to yellow or yellow-green when the cyanobacterium synechococcus sp. strain pcc 7942 is deprived of an essential nutrient. we found that this bleaching process (chlorosis) in cells deprived of sulfur (s) was similar to that in cells deprived of nitrogen (n), but that cells deprived of phosphorus (p) bleached differently. cells divided once after n deprivation, twice after s deprivation, and four times after p deprivation. chlorophyll (chl) accumulati ... | 1992 | 1624459 |
| ntca, a global nitrogen regulator from the cyanobacterium synechococcus that belongs to the crp family of bacterial regulators. | the gene ntca is required for full expression of proteins subject to ammonium repression in the cyanobacterium synechococcus. a 3.1 kb dna fragment able to complement an ntca mutant was digested with exonuclease iii, and deleted fragments of different size were tested for complementation of that mutant, allowing the localization of its mutation within a bamhi-hindiii genomic fragment of c. 0.4 kb. insertion of a chloramphenicol-resistance-encoding gene cassette into both the bamhi and the hindii ... | 1992 | 1630321 |
| ferredoxin and flavodoxin from the cyanobacterium synechocystis sp pcc 6803. | the unicellular cyanobacterium synechocystis sp pcc 6803 is capable of synthesizing two different photosystem-i electron acceptors, ferredoxin and flavodoxin. under normal growth conditions a [2fe-2s] ferredoxin was recovered and purified to homogeneity. the complete amino-acid sequence of this protein was established. the isoelectric point (pi = 3.48), midpoint redox potential (em = -0.412 v) and stability under denaturing conditions were also determined. this ferredoxin exhibits an unusual ele ... | 1992 | 1633177 |
| phytochrome assembly. the structure and biological activity of 2(r),3(e)-phytochromobilin derived from phycobiliproteins. | the unicellular rhodophyte, porphyridium cruentum, and the filamentous cyanobacterium, calothrix sp. pcc 7601, contain phycobiliproteins that have covalently bound phycobilin chromophores. overnight incubation of solvent-extracted cells at 40 degrees c with methanol liberates free phycobilins that are derived from the protein-bound bilins by methanolytic cleavage of the thioether linkages between bilin and apoprotein. two of the free bilins were identified as 3(e)-phycocyanobilin and 3(e)-phycoe ... | 1992 | 1634523 |
| roles of fad and 8-hydroxy-5-deazaflavin chromophores in photoreactivation by anacystis nidulans dna photolyase. | dna photolyase from the cyanobacterium anacystis nidulans contains two chromophores, flavin adenine dinucleotide (fadh2) and 8-hydroxy-5-deazaflavin (8-hdf) (eker, a. p. m., kooiman, p., hessels, j. k. c., and yasui, a. (1990) j. biol. chem. 265, 8009-8015). while evidence exists that the flavin chromophore (in fadh2 form) can catalyze photorepair directly and that the 8-hdf chromophore is the major photosensitizer in photoreactivation it was not known whether 8-hdf splits pyrimidine dimer direc ... | 1992 | 1639785 |
| cloning and sequence analysis of the glucose-6-phosphate dehydrogenase gene from the cyanobacterium synechococcus pcc 7942. | the glucose-6-phosphate dehydrogenase (ec 1.1.1.49) gene (zwf) of the cyanobacterium synechococcus pcc 7942 was cloned on a 2.8 kb hind iii fragment. sequence analysis revealed an orf of 1572 nucleotides encoding a polypeptide of 524 amino acids which exhibited 41% identity with the glucose-6-phosphate dehydrogenase of escherichia coli. | 1992 | 1643289 |
| characterization of phycocyanin produced by cpce and cpcf mutants and identification of an intergenic suppressor of the defect in bilin attachment. | mutants of the cyanobacterium synechococcus sp. pcc 7002 constructed by the insertional inactivation of either the cpce or cpcf gene produce low levels of spectroscopically detectable phycocyanin. the majority of the phycocyanin produced in these strains appears to lack the alpha subunit phycocyanobilin (pcb) chromophore (zhou, j., gasparich, g. e., stirewalt, v. l., de lorimier, r., and bryant, d. a. (1992) j. biol. chem. 267, 16138-16145). purification of the phycocyanin produced in the mutant ... | 1992 | 1644802 |
| instability of tn5 in a plasmid cloning vector for the cyanobacterium anacystis nidulans. | transposon tn5 was used to produce insertions within the region of a cyanobacterial shuttle vector previously identified as necessary for transformation of anacystis nidulans. these transposon-containing plasmids were used to transform a plasmid-cured derivative of anacystis strain r2 and tested for structural stability of the transforming plasmid. the transposon dna was deleted from all the plasmids containing tn5 within the cyanobacterial replication region. inserts in the vector dna were phys ... | 1991 | 1650005 |
| [2 site-specific endonucleases of the cyanobacterium nostoc linckia]. | two restrictases nli387/7 i and nli387/7 ii have been isolated from cyanobacterium nostoc linckia using chromatography on phosphocellulose, "mono q" column, and heparin sepharose 4b. the preparations are described by the method of electrophoresis in polyacrylamide gel under denaturing conditions. catalytic properties of restrictases are determined: optimal ph of the action--9.0--9.5, optimal concentration of na+--5 mm, that of mg2+--6 mm, optimal temperature--37 degrees c. the isolated enzymes a ... | 1991 | 1650423 |
| ultrastructural and electron spectroscopic analyses of cyanobacteria and bacteria. | the extracellular sheath material and some intracellular cell components of cyanobacteria and phosphate-accumulating sewage bacteria were analysed by electron spectroscopic imaging (esi) and electron energy-loss spectroscopy (eels). the specimens were embedded in water-soluble nanoplast resin without any previous fixation and ultrathin sections were examined in a zeiss cem 902 microscope. a high sulphur content was detected in the inner sheath of the cyanobacterium gloeothece. the elemental comp ... | 1991 | 1651393 |
| characterization of insertion sequence is892 and related elements from the cyanobacterium anabaena sp. strain pcc 7120. | is892, one of the several insertion sequence (is) elements discovered in anabaena sp. strain pcc 7120 (y. cai and c. p. wolk, j. bacteriol. 172:3138-3145, 1990), is 1,675 bp with 24-bp near-perfect inverted terminal repeats and has two open reading frames (orfs) that could code for proteins of 233 and 137 amino acids. upon insertion into target sites, this is generates an 8-bp directly repeated target duplication. a 32-bp sequence in the region between orf1 and orf2 is similar to the sequence of ... | 1991 | 1653218 |
| characterization of the is895 family of insertion sequences from the cyanobacterium anabaena sp. strain pcc 7120. | a family of repetitive elements from the cyanobacterium anabaena sp. strain pcc 7120 was identified through the proximity of one element to the psbai gene. four members of this seven-member family were isolated and shown to have structures characteristic of bacterial insertion sequences. each element is approximately 1,200 bp in length, is delimited by a 30-bp inverted repeat, and contains two open reading frames in tandem on the same dna strand. the four copies differ from each other by small i ... | 1991 | 1653219 |
| cyanobacterial nodularin is a potent inhibitor of type 1 and type 2a protein phosphatases. | the present study characterizes the inhibitory effects of nodularin, a recently isolated hepatotoxic compound from the cyanobacterium nodularia spumigena, on type 1 (pp1), type 2a, (pp2a), type 2b (pp2b), and type 2c (pp2c) protein phosphatases. both pp2a and pp1 were potently inhibited (ic50 = 0.026 and 1.8 nm, respectively) by nodularin, whereas pp2b was inhibited to a lesser extent (ic50 = 8.7 microm). nodularin had no apparent effect on pp2c, alkaline phosphatase, acid phosphatase, insulin r ... | 1991 | 1656193 |
| unique modification of adenine in genomic dna of the marine cyanobacterium trichodesmium sp. strain nibb 1067. | the genomic dna of the marine nonheterocystous nitrogen-fixing cyanobacterium trichodesmium sp. strain nibb 1067 was found to be highly resistant to dna restriction endonucleases. the dna was digested extensively by the restriction enzyme dpni, which requires adenine methylation for activity. the dna composition, determined by high-performance liquid chromatography (hplc), was found to be 69% at. surprisingly, it was found that a modified adenine which was not methylated at the usual n6 position ... | 1991 | 1657876 |
| directed mutagenesis of an iron-sulfur protein of the photosystem i complex in the filamentous cyanobacterium anabaena variabilis atcc 29413. | in oxygenic photosynthetic organisms the psi-c polypeptide, encoded by the psac gene, provides the ligands for two [4fe-4s] centers, fa and fb, the terminal electron acceptors in the photosystem i (psi) complex. an insertion mutation introduced in the psac locus of the filamentous cyanobacterium anabaena variabilis atcc 29413 resulted in the creation of a mutant strain, t398-1, that lacks the psi-c polypeptide. in medium supplemented with 5 mm fructose, the mutant cells grew well in the dark. ho ... | 1991 | 1658798 |