Publications

arrangement of nitrogenase structural genes in an aerobic filamentous nonheterocystous cyanobacterium.	members of the marine filamentous, nonheterocystous cyanobacterial genus trichodesmium not only are capable of fixing nitrogen aerobically in the light but when grown under a light-dark cycle will fix nitrogen only during the light phase. in this study, we constructed a restriction map of the structural nitrogen fixation genes (nifhdk) in trichodesmium sp. strain nibb 1067. we found that the organization of the nif genes in trichodesmium sp. strain nibb 1067 is contiguous, as found in other nonh ...	1991	1938909
independent regulation of nifhdk operon transcription and dna rearrangement during heterocyst differentiation in the cyanobacterium anabaena sp. strain pcc 7120.	the filamentous cyanobacterium anabaena sp. strain pcc 7120 expresses the genes required for nitrogen fixation in terminally differentiated cells called heterocysts. the nifhdk operon encodes the nitrogenase polypeptides and is expressed at high levels in heterocysts. during heterocyst differentiation, an 11-kb dna element is excised from the nifd gene by site-specific recombination. the xisa gene, located on the 11-kb element, is required for the excision of the element. transcription and dna r ...	1991	1938911
physiological sources of reductant for nitrogen fixation activity in nostoc sp. strain ucd 7801 in symbiotic association with anthoceros punctatus.	pure cultures of the symbiotic cyanobacterium-bryophyte association with anthoceros punctatus were reconstituted by using nostoc sp. strain ucd 7801 or its 3-(3,4-dichlorophenol)-1,1-dimethylurea (dcmu)-resistant mutant strain, ucd 218. the cultures were grown under high light intensity with co2 as the sole carbon source and then incubated in the dark to deplete endogenous reductant pools before measurements of nitrogenase activities (acetylene reduction). high rates of light-dependent acetylene ...	1991	1938924
molecular cloning and targeted mutagenesis of the gene psaf encoding subunit iii of photosystem i from the cyanobacterium synechocystis sp. pcc 6803.	photosystem i is one of the two multisubunit pigment-protein complexes in the thylakoid membranes of cyanobacteria. subunit iii of photosystem i complex was isolated from a mutant of the cyanonbacterium synechocystis sp pcc 6803, which lacks subunit ii. the sequence of its nh2-terminal residues was determined and corresponding oligonucleotide probes were used to isolate the gene encoding this subunit. the gene, designated as psaf, codes for a mature protein of 15705 da that is synthesized with a ...	1991	1939076
amino acid sequence of 10-kda protein in photosystem i reaction-center complex from a thermophilic cyanobacterium, synechococcus elongatus naegeli.	four small subunits (14, 13, 10, and 8 kda) of the photosystem i reaction-center complex were isolated from a thermophilic cyanobacterium synechococcus elongatus. the complete amino acid sequence of the 10-kda subunit was determined to consist of 80 amino acid residues giving a molecular mass of 8855.3, excluding iron and sulfur atoms, and containing two special sequences of cysteine residues, cys-x-x-cys-x-x-cys-x-x-x-cys-pro, at residues 10-21 and 47-58, which indicates that the subunit is an ...	1991	1946336
catalytic properties of recombinant octameric, hexadecameric, and heterologous cyanobacterial/bacterial ribulose- 1,5-bisphosphate carboxylase/oxygenase.	the recent isolation of a catalytically competent recombinant octameric core of the hexadecameric ribulose-1,5-bisphosphate carboxylase/oxygenase from the cyanobacterium anacystis nidulans (synechococcus) (b. lee and f. r. tabita, 1990, biochemistry 29, 9352-9357) has provided a useful system for examining the properties of this enzyme in the absence of small subunits. unlike most sources of hexadecameric ribulose bisphosphate carboxylase, the nonactivated anacystis holoenzyme was not inhibited ...	1991	1952939
binding of cadmium by cyanobacterial growth media: free ion concentration as a toxicity index to the cyanobacterium nostoc uam 208.	a quantitative study of cadmium binding to three different growth media for nitrogen-fixing cyanobacteria was done with the aid of a solid state ion-specific electrode. kratz and myers modified medium and arnon medium bound large amounts of cd2+, bg11o medium had less binding capacity. of the media components, phosphate ion showed the greatest ability to bind cd2+. different phs, the size of cell inoculum and two buffers (tricine and hepes, 25 mm) also changed the availability of free cadmium io ...	1991	1953030
cytochrome c-553 is not required for photosynthetic activity in the cyanobacterium synechococcus.	in cyanobacteria, the water-soluble cytochrome c-553 functions as a mobile carrier of electrons between the membrane-bound cytochrome b6-f complex and p-700 reaction centers of photosystem i. the structural gene for cytochrome c-553 (designated cyta) of the cyanobacterium synechococcus sp. pcc 7942 was cloned, and the deduced amino acid sequence was shown to be similar to known cyanobacterial cytochrome c-553 proteins. a deletion mutant was constructed that had no detectable cytochrome c-553 bas ...	1990	1967057
identification and cloning of a regulatory gene for nitrogen assimilation in the cyanobacterium synechococcus sp. strain pcc 7942.	twenty-seven mutants that were unable to assimilate nitrate were isolated from synechococcus sp. strain pcc 7942. in addition to mutants that lacked nitrate reductase or nitrite reductase, seven pleiotropic mutants impaired in both reductases, glutamine synthetase, and methylammonium transport were also isolated. one of the pleiotropic mutants was complemented by transformation with a cosmid gene bank from wild-type strain pcc 7942. three complementing cosmids were isolated, and a 3.1-kilobase-p ...	1990	1967601
cloning and nucleotide sequence of an archaebacterial glutamine synthetase gene: phylogenetic implications.	the glna gene of the thermophilic sulphur-dependent archaebacterium sulfolobus solfataricus was identified by hybridization with the corresponding gene of the cyanobacterium spirulina platensis and cloned in escherichia coli. the nucleotide sequence of the 1696 bp dna fragment containing the structural gene for glutamine synthetase was determined, and the derived amino acid sequence (471 residues) was compared to the sequences of glutamine synthetases from eubacteria and eukaryotes. the homology ...	1990	1973523
genetic transformation of glutamine auxotrophy to prototrophy in the cyanobacterium nostoc muscorum.	glutamine auxotrophic (gln-) and l-methionine d,l-sulfoximine (msx) resistant (msxr) mutants of n. muscorum were isolated and characterized for nitrogen nutrition, nitrogenase activity, glutamine synthetase (gs) activity and glutamine amide, alpha-keto-glutarate amido transferase (gogat) activity. the glutamine auxotroph was found to the gogat-containing gs-defective, incapable of growth with n2 or nh4+ but capable of growth with glutamine as nitrogen source, thus, suggesting gs to be the primar ...	1990	1978772
neutralization of microcystin shock in mice by tumor necrosis factor alpha antiserum.	microcystis aeruginosa is a common cyanobacterium in water blooms that appear widely in nutrient-rich, fresh, and brackish waters, and its toxic blooms cause the death of domestic animals. the administration of a crude toxic cell extract of m. aeruginosa k-139 to mice can produce tumor necrosis factor (tnf) and prompt severe physiological disturbances, especially liver damage, which can lead to death. the in vitro production of tnf-alpha by peritoneal macrophages was observed after stimulation w ...	1991	2036020
cellular differentiation in the process of generation of the eukaryotic cell.	primitive atmosphere of the earth did not contain oxygen gas (o2) when the proto-cells were generated successfully as the result of chemical evolution and then evolved. therefore, they first had acquired anaerobic energy metabolism, fermentation. the cellular metabolisms have often been formed by reorganizing to combine or recombinate between pre-existing metabolisms and newly born bioreactions. photosynthetic metabolism in eukaryotic chloroplast consists of an electron-transfer photosystem and ...	1990	2103939
the antipsoriatic compound anthralin influences bioenergetic parameters and redox properties of energy transducing membranes.	bioenergetic parameters and redox properties of energy transducing membranes in rat liver mitochondria and cyanobacteria were investigated in the presence of the antipsoriatic compound anthralin (1,8-dihydroxy-9-anthrone). transmembrane ph and electrical gradients were determined using electron paramagnetic resonance spectroscopy. in mitochondria, ubiquinones 9,10 and other redox components of the electron transport chain are reduced by anthralin; the proton motive force is increased. in the abs ...	1990	2104916
the psbc start codon in synechocystis sp. pcc 6803.	the translation start codon for psbc, the gene encoding cp43, a chlorophyll-binding protein of photosystem ii, has been identified for the cyanobacterium synechosystis sp. pcc 6803 using site-directed mutagenesis. an aug codon, about 50 bases upstream from the end of psbd-i had previously been assumed to be the translation start site of psbc. however, the fact that the aug codon is not present in psbc from several other organisms, whereas a gug codon 14 bases upstream from the end of psbd-i is s ...	1990	2105233
amino acid sequence of photosystem i subunit iv from the cyanobacterium synechocystis pcc 6803.	we describe here the complete amino acid sequence of photosystem i subunit iv from synechocystis 6803. the molecular mass of 8.0 kda is lower than in higher plants and chlamydomonas, due to the lack of a characteristic, proline-rich, n-terminal sequence. the remaining sequence exhibits a good conservation, with a hydrophilic and strongly basic n-terminal head followed by two hydrophobic domains. there is no possibility of classical membrane-spanning alpha helices. this component is likely to be ...	1990	2105239
modification of dinitrogenase reductase in the cyanobacterium anabaena variabilis due to c starvation and ammonia.	in the heterocystous cyanobacterium anabaena variabilis, a change in nitrogenase activity and concomitant modification of dinitrogenase reductase (the fe protein of nitrogenase) was induced either by nh4cl at ph 10 (s. reich and p. böger, fems microbiol. lett. 58:81-86, 1989) or by cessation of c supply resulting from darkness, co2 limitation, or inhibition of photosystem ii activity. modification induced by both c limitation and nh4cl was efficiently prevented by anaerobic conditions. under air ...	1990	2105302
nucleotide sequence and further characterization of the synechococcus sp. strain pcc 7002 reca gene: complementation of a cyanobacterial reca mutation by the escherichia coli reca gene.	the nucleotide sequence and transcript initiation site of the synechococcus sp. strain pcc 7002 reca gene have been determined. the deduced amino acid sequence of the reca protein of this cyanobacterium is 56% identical and 73% similar to the escherichia coli reca protein. northern (rna) blot analysis indicates that the synechococcus strain pcc 7002 reca gene is transcribed as a monocistronic transcript 1,200 bases in length. the 5' endpoint of the reca mrna was mapped by primer extension by usi ...	1990	2105307
transport of basic amino acids by the dinitrogen-fixing cyanobacterium anabaena pcc 7120.	two transport systems for l-arginine were evident in anabaena sp. strain pcc 7120: a high-affinity one (km, 1.7 microm) that accumulated arginine within the cells through an energy-requiring process and another one that exhibited low affinity for l-arginine (km, 0.75 mm) and was unable to accumulate the substrate. both systems were inhibited by l-canavanine, l-lysine, and l-ornithine. two systems were also evident for l-lysine uptake (km, 1.9 and 110 microm, respectively). after selection for re ...	1990	2105956
genes for phycocyanin subunits in synechocystis sp. strain pcc 6701 and assembly mutant uv16.	the cyanobacterial phycobilisome is a large protein complex located on the photosynthetic membrane. it harvests light energy and transfers it to chlorophyll for use in photosynthesis. phycobilisome assembly mutants in the unicellular cyanobacterium synechocystis sp. strain 6701 have been characterized. one such mutant, uv16, contains a defect in the assembly of the biliprotein phycocyanin. we report the cloning and sequencing of the phycocyanin genes from wild-type synechocystis strain 6701 and ...	1990	2106506
structure and light-regulated expression of phycoerythrin genes in wild-type and phycobilisome assembly mutants of synechocystis sp. strain pcc 6701.	phycoerythrin is a major pigmented component of the phycobilisome, a cyanobacterial light-harvesting complex. it contains bilin-type chromophores that absorb and transfer light energy to chlorophyll protein complexes of the photosynthetic membranes. in many cyanobacteria, phycoerythrin expression is regulated by light wavelength in a response known as chromatic adaptation. green light-grown cells contain higher levels of this biliprotein than do cells grown in red light. the phycoerythrin gene s ...	1990	2106507
refined three-dimensional structure of phycoerythrocyanin from the cyanobacterium mastigocladus laminosus at 2.7 a.	the structure of the phycobiliprotein phycoerythrocyanin from the thermophilic cyanobacterium mastigocladus laminosus has been determined at 2.7 a resolution by x-ray diffraction methods on the basis of the molecular model of c-phycocyanin from the same organism. hexagonal phycoerythrocyanin crystals of space group p6(3) with cell constants a = b = 156.86 a, c = 40.39 a, alpha = beta = 90 degrees, gamma = 120 degrees are almost isomorphous to c-phycocyanin crystals. the crystal structure has bee ...	1990	2106585
nucleotide sequence of the psbh gene of the cyanobacterium synechocystis 6803.		1990	2106663
membrane lipid composition, fluidity, and surface charge changes in response to growth of the fresh water cyanobacterium synechococcus 6311 under high salinity.	the effect of adaptation to saline growth of a fresh water cyanobacterium synechococcus 6311 on components of the cytoplasmic membranes and thylakoids was investigated. significant changes in membrane surface charge, lipid, fatty acid, and carotenoid composition were observed upon transfer of the cells from a low salt (0.015 m nacl) to a high salt (0.50 m nacl) growth medium. very similar changes in the polar lipid classes and fatty acid composition were observed in both membranes, but changes i ...	1990	2106828
chromosomal transformation in the cyanobacterium agmenellum quadruplicatum.	chromosomal transformation of agmenellum quadruplicatum pr-6 (= synechococcus sp. strain 7002) was characterized for phenotypic expression, for exposure time to dna, and for dependence on dna concentration with regard to rifr donor dna. exponentially growing cells of pr-6 were competent for chromosomal transformation. competence decreased in cells in the stationary phase of growth or in cells deprived of a nitrogen source. dark incubation of cells before exposure to donor dna also decreased comp ...	1990	2108126
different and rapid responses of four cyanobacterial psba transcripts to changes in light intensity.	the genome of the cyanobacterium synechococcus sp. strain pcc 7942 contains three psba genes which encode two forms of the d1 protein of photosystem ii. experiments using psba-lacz translational fusions and western blot (immunoblot) analysis have shown that the psba genes respond differently to changes in light intensity, altering the ratio of the two forms of d1 in the thylakoid membrane. each gene produces a 1.2-kilobase (kb) mrna. a probe specific for psbaii transcripts also identified a 1.6- ...	1990	2108129
a critical arginine in the large subunit of ribulose bisphosphate carboxylase/oxygenase identified by site-directed mutagenesis.	rapid inactivation by phenylglyoxal of ribulose bisphosphate carboxylase/oxygenase (ribulose-p2 carboxylase) from the cyanobacterium anacystis nidulans suggests the presence of an essential arginine, the modification of which is reduced in the presence of the substrate ribulose bisphosphate. arginine 292 in the large subunit of ribulose-p2 carboxylase from a. nidulans was chosen for site-directed mutagenesis studies on the basis of the complete conservation of this residue in corresponding seque ...	1990	2108139
purification and characterization of photosystem i and photosystem ii core complexes from wild-type and phycocyanin-deficient strains of the cyanobacterium synechocystis pcc 6803.	highly photoactive photosystem i (ps i) and photosystem ii (ps ii) core complexes have been isolated from the cyanobacterium synechocystis pasteur culture collection (pcc) 6803 and a phycocyanin-deficient mutant, enriched in ps ii. cell breakage using glass beads was followed by sucrose density gradient centrifugation and two high-performance liquid chromatography steps involving anion-exchange and hydroxyapatite. the ps i core complex has an apparent molecular mass of 300 +/- 20 kda (including ...	1990	2108153
nucleotide sequence of the psbk gene of the cyanobacterium synechocystis 6803.		1990	2108431
molecular weight determination of an active photosystem i preparation from a thermophilic cyanobacterium, synechococcus elongatus.	an active photosystem i (psi) complex was isolated from the thermophilic cyanobacterium synechococcus elongatus by a procedure consisting of three steps: first, extraction of photosystem ii from the thylakoids by a sulfobetaine detergent yields psi-enriched membranes. second, the latter are treated with triton x-100 to extract psi particles, which are further purified by preparative isoelectric focusing. third, anion-exchange chromatography is used to remove contaminating phycobilisome polypepti ...	1990	2108724
organization and nucleotide sequence of the genes for ribosomal protein s2 and elongation factor ts in spirulina platensis.	a 6.5 kb region from the genome of the cyanobacterium spirulina platensis was cloned using as a probe the escherichia coli gene for ribosomal protein s2. sequence analysis revealed, in this region, the presence of the gene for ribosomal protein s2 and part of the gene for the elongation factor ts (ef-ts). the arrangement rpsb-spacer-tsf resembles that reported for e. coli. the deduced amino acid sequences of the platensis s2 and ef-ts show significant homology with the e. coli counterparts.	1990	2108895
isolation and characterization of the minor components associated with microcystins lr and rr in the cyanobacterium (blue-green algae).	two structurally similar analogues of microcystins lr and rr, cyclic peptide hepatotoxins from microcystis, were isolated by chromatographic methods. although they have the same mol. wt and amino acid compositions as those of the parent toxins, they do not possess similar toxicities. ultraviolet and 1h-nmr spectral data for both components demonstrate clear structural difference of these cyclic peptides from the parent toxins, which are probably responsible for the marked decreases in their obse ...	1990	2109908
relationship between dna cycle and growth rate in synechococcus sp. strain pcc 6301.	flow cytometry was used to examine cell cycle regulation in synechococcus sp. strain pcc 6301 under a variety of growth conditions. the dna frequency distributions of exponentially growing and dark-blocked populations confirmed that this cyanobacterium contains multiple chromosome copies even at very slow growth rates. furthermore, the presence of major peaks corresponding to other than 2" chromosome copies strongly suggests that dna replication is initiated asynchronously. although this suggest ...	1990	2110139
highly repetitive dna sequences in cyanobacterial genomes.	we characterized three distinct families of repeated sequences in the genome of the cyanobacterium calothrix sp. strain pcc 7601. these repeated sequences were present at a level of about 100 copies per calothrix genome and consisted of tandemly amplified heptanucleotides. these elements were named short tandemly repeated repetitive (strr) sequences. we used the three different calothrix strr sequences as probes to perform southern hybridization experiments with dnas extracted from various cyano ...	1990	2110150
control of nitrogenase recovery from oxygen inactivation by ammonia in the cyanobacterium anabaena sp. strain ca (atcc 33047).	the control of nitrogenase recovery from inactivation by oxygen was studied in anabaena sp. strain ca (atcc 33047). nitrogenase activity (acetylene reduction) in cultures grown in 1% co2 in air was inhibited by exposure to 1% co2-99% o2 and allowed to recover in the presence of high oxygen tensions. cultures exposed to hyperbaric levels of oxygen in the presence of 10 mm nh4no3 were incapable of regaining nitrogenase activity, whereas control cultures returned to 65 to 80% of their original acti ...	1990	2110151
dna photoreactivating enzyme from the cyanobacterium anacystis nidulans.	photoreactivating enzyme, which specifically monomerizes pyrimidine dimers in uv-irradiated dna, was purified 21,000-fold from the cyanobacterium anacystis nidulans to apparent homogeneity with 41% overall yield. the enzyme consists of a single protein chain with 53,000 molecular weight. maximal activity was found at ph 6.2 and 0.1 m nacl. purified photoreactivating enzyme exhibits a marked absorption spectrum with a main band in the blue region (maximum 437 nm), a protein band (maximum 266 nm), ...	1990	2110564
modification of a glnb-like gene product by photosynthetic electron transport in the cyanobacterium synechococcus 6301.	covalent modification of a 13 kda soluble-phase protein occurs during adaptation of cells of the cyanobacterium synechococcus 6301 (mutant an112) to light specifically absorbed by photosystem ii. this adaptation is accompanied by functional changes indicative of altered excitation energy distribution between the photosystems. the 13 kda protein is identified by solid-phase n-terminal sequencing as a protein related to pii, the glnb gene product of e. coli. in e. coli, the pii protein undergoes u ...	1990	2110911
power transmission along biological membranes.	hypothesis on long-distance power transmission along extended energy-transducing membranes (skulachev, 1969, 1971, 1980), has been experimentally proven in four different systems, namely, (i) trichomes of filamentous cyanobacterium phormidium uncinatum; (ii) filamentous mitochondria and mitochondrial network in fibroblasts; (iii) clusters of roundish heart muscle mitochondria interconnected with mitochondrial junctions; (iv) mixed animal cell cultures interconnected with gap junctions. in all ca ...	1990	2111408
identification and characterization of heta, a gene that acts early in the process of morphological differentiation of heterocysts.	envelope polysaccharide is a major early diagnostic of differentiating heterocysts. the mutation in mutant ef116 of anabaena sp. strain pcc 7120 reduces the cohesiveness of this polysaccharide. a 3.5-kilobase fragment of dna cloned from the wild type of this anabaena sp. was previously shown to complement this mutation. we present the nucleotide sequence of a 2,555-base-pair portion of this fragment containing an open reading frame (orf) of 601 amino acids. complementation analysis using deletio ...	1990	2111805
an autolytic substance in a freshwater cyanobacterium phormidium tenue.	an autolytic substance in an axenic cyanobacterium, phormidium tenue, was identified as a mixture of fatty acids, by use of cultured cells in the laboratory. among them, linoleic acid and linolenic acid were potent growth inhibitors.	1990	2112049
characterization of cryptic plasmids from marine cyanobacteria and construction of a hybrid plasmid potentially capable of transformation of marine cyanobacterium, synechococcus sp., and its transformation.	among forty strains of marine cyanobacteria isolated in our laboratory, five strains had 1-3 different plasmids. the unicellular marine cyanobacterium, synechococcus sp. nkbg 042902, contains at least three plasmids (psy09, psy10, and psy11). however, these plasmids are cryptic. therefore, a hybrid plasmid pusy02 containing the 1.4-kb hindiii fragment of psy11 and escherichia coli plasmid puc18 was constructed. the plasmid pusy02 transformed both marine synechococcus sp. nkbg042902-yg1116, which ...	1990	2112896
changes of some physical properties of isolated and purified plasma and thylakoid membrane vesicles from the freshwater cyanobacterium synechococcus 6301 (anacystis nidulans) during adaptation to salinity.	photoautotrophically growing cultures of the freshwater cyanobacterium anacystis nidulans (synechococcus sp.) became adapted to the presence of 0.4-0.5 m nacl in the growth medium (about seawater level) with a lag phase of 2 days after which time the growth rate resumed at 80-90% of the control. major changes in structure and function of the plasma membranes (and, to a much lesser extent, of the thylakoid membranes) were found to accompany the adaptation process. plasma and thylakoid membranes w ...	1990	2112897
[the surface membrane charge of bacteria and its role in serine proteinase secretion by bacillus subtilis cells].	univalent, bivalent and trivalent metal cations increase the fluorescence yield of 9-aminoacridine in the suspensions of chromatophores of the purple nonsulfur bacterium rhodospirillum rubrum isolated thylakoid membranes and cells of cyanobacterium anabaena variabilis, cells bacillus subtilis. the active cation concentrations increase about in 10 times with the decrease of their valency by one. it points to the fact that the changes in 9-aminoacridine fluorescence serve for the monitoring of the ...	1990	2112959
thermal stability of electron transport in ps ii membranes and particles from the thermophilic cyanobacteria.	thermal stability of the ferricyanide (fc) and dichlorophenolindophenol (dcip) reducing reactions was investigated in isolated membrane preparations and ps ii particles with active water splitting system from the cyanobacterium synechococcus elongatus. in a hypotonic medium, the thermostability was seen to be much higher for the dcip than for the fc reduction reaction. after the addition of high concentrations of polyethylene glycol (mwt = 4000) or sodium citrate to the medium, the fc reduction ...	1990	2113502
nucleotide sequence of the psac gene of the cyanobacterium synechococcus vulcanus.		1990	2114016
structure and mutation of a gene encoding a mr 33,000 phycocyanin-associated linker polypeptide.	the gene encoding a phycocyanin-associated linker polypeptide of mr 33,000 from the cyanobacterium synechococcus sp. pcc 7002 was found to be located adjacent and 3' to the genes encoding the alpha and beta subunits of phycocyanin. the identity of this gene, designated cpcc, was proven by matching the amino-terminal sequence of the authentic polypeptide with that predicted by the nucleotide sequence. a cpcc mutant strain of this cyanobacterium was constructed. the effect of the mutation was to p ...	1990	2114862
nucleotide sequence of the psbi gene of the cyanobacterium, anacystis nidulans 6301.		1990	2115674
targeted deletion mutagenesis of the beta subunit of cytochrome b559 protein destabilizes the reaction center of photosystem ii.	oligonucleotide-directed mutagenesis techniques were used to delete the psbf gene, encoding the beta subunit of the cytochrome b559 protein of the photosystem ii complex in the cyanobacterium, synechocystis 6803. cyt b559 is an integral component of ps ii complex. however, its precise functional role in ps ii remains to be determined. previously, we created a mutant in which the psbf gene as well as three of its neighbouring genes, psbe, psbl and psbj were simultaneously deleted from the chromos ...	1990	2116128
cloning a gene coding for norflurazon resistance in cyanobacteria.	the herbicide norflurazon inhibits carotene biosynthesis in photosynthetic organisms by blocking the enzyme phytoene dehydrogenase (= phytoene desaturase). we have isolated norflurazon-resistant mutants of the cyanobacterium synechococcus pcc7942. the herbicide-resistance gene from the mutant nfz4 has been cloned by genetic complementation of the resistance trait in wild type cells. the experiment described here illustrates the usefulness of employing cyanobacteria to clone herbicide-resistance ...	1990	2116131
molecular characterization of genes coding for wild-type and sulfonylurea-resistant acetolactate synthase in the cyanobacterium synechococcus pcc7942.	we present here the isolation and molecular characterization of acetolactate synthase (als) genes from the cyanobacterium synechococcus pcc7942 which specify a sulfonylurea-sensitive enzyme and from the sulfonylurea-resistant mutant sm 3/20, which specify resistance to sulfonylurea herbicides. the als gene was cloned and mapped by complementation of an escherichia coli ilv auxotroph that requires branched-chain amino acids for growth and lacks als activity. the cyanobacterial gene is efficiently ...	1990	2116132
differential sensitivity of bicarbonate-reversible formate effects on herbicide-resistant mutants of synechocystis 6714.	herbicide-resistant mutants of the cyanobacterium synechocystis 6714, that are altered in specific amino acids in their d-1 protein, shows differential sensitivity to formate treatment. measurements on oxygen yield in a sequence of flashes, chlorophyll (chl) a fluorescence transients and chl a fluorescence yield decay after a flash reveal that the resistance of cells to formate treatment is in the following (highest to lowest) order: [double mutant] a251v/f211s (az v) greater than [single mutant ...	1990	2116323
isolation of characterization of two sequence-specific endonucleases from the cyanobacterium synechocystis sp. pcc 6308.	the first two restriction endonucleases to be characterized in the cyanobacterium synechocystis sp. pcc 6308 are described. syni, an avaii isoschizomer, recognizes the base sequence 5-gg[at]cc-3. synii, an xmni isoschizomer, recognizes the sequence 5-gaannnnttc-3.	1990	2116348
construction of lacz promoter probe vectors for use in synechococcus: application to the identification of co2-regulated promoters.	it was shown that the escherichia coli lacz gene could be expressed in the cyanobacterium synechococcus r2 pcc7942 both as a plasmid-borne form and also integrated into the chromosome. a promoterless form of the lacz gene was constructed and used as a reporter gene to make transcriptional fusions with cyanobacterial promoters using a shuttle vector system and also via a process of integration by homologous recombination. synechococcus r2 promoter-lacz gene fusions were then used to identify co2- ...	1990	2116369
comparison of the kinetics of reduction and intramolecular electron transfer in electrostatic and covalent complexes of ferredoxin-nadp+ reductase and flavodoxin from anabaena pcc 7119.	the kinetics of reduction and intracomplex electron transfer in electrostatically stabilized and covalently crosslinked complexes between ferredoxin-nadp+ reductase (fnr) and flavodoxin (fld) from the cyanobacterium anabaena pcc 7119 were compared using laser flash photolysis. the second-order rate constant for reduction by 5-deazariboflavin semiquinone (drfh) of fnr within the electrostatically stabilized complex at 10 mm ionic strength (4.0 x 10(8) m-1 s-1) was identical to that for free fnr. ...	1990	2116771
glu-69 of the d2 protein in photosystem ii is a potential ligand to mn involved in photosynthetic oxygen evolution.	to probe the involvement of amino acid residues of the d2 protein in the water-splitting process in photosystem ii, site-directed mutagenesis was applied to identify d2 residues that might contribute to binding the mn cluster involved in oxygen evolution. mutation of glu-69 to gln or val in d2 of the cyanobacterium synechocystis sp. pcc 6803 was found to lead to a loss of photoautotrophic growth. however, in cells of the gln mutant (e69q) a significant hill reaction rate could be observed upon t ...	1990	2116897
a morphometric and x-ray energy dispersive approach to monitoring ph-altered cadmium toxicity in anabaena flos-aquae.	cadmium toxicity and uptake as influenced by different ph values have been studied in the freshwater cyanobacterium anabaena flos-aquae, using the techniques of morphometric analysis, x-ray energy dispersive analysis and atomic absorption spectrophotometry. a general reduction in cell dimension, thylakoid surface area, number and volume of polyhedral bodies, polyphosphate bodies, cyanophycin granules, lipid bodies, membrane limited crystalline inclusions, volume and number of wall layers and mes ...	1990	2117425
the toxicity and bioaccumulation of selenate, selenite and seleno-l-methionine in the cyanobacterium anabaena flos-aquae.	a laboratory investigation was conducted to study the toxicity and bioaccumulation of seleno-l-methionine, selenate and selenite in the cyanobacterium anabaena flos-aquae. the first sub-lethal effects of seleno-l-methionine, selenite and selenate occurred at 0.1, 3.0, and 3.0 mg/l, respectively with a decrease in chlorophyll a concentration (p less than 0.0001). selenium bioconcentration factors (bcf) were in the order of seleno-l-methionine, selenite, and selenate. significant decreases in intr ...	1990	2117426
structure of a hepatotoxic pentapeptide from the cyanobacterium nodularia spumigena.	the structure of a hepatotoxic peptide from the cyanobacterium nodularia spumigena was determined using 1d and 2d proton nuclear magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. the toxin was a cyclic pentapeptide (mol. wt 824.5) with the structure cyclo-(beta-methylisoasp-arg-adda-isoglu-n-methylde hydrobutyric acid) (adda: 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid).	1990	2117781
the purification and preliminary x-ray diffraction studies of recombinant synechococcus ribulose-1,5-bisphosphate carboxylase/oxygenase from escherichia coli.	x-ray crystallographic diffraction data has been collected for recombinant hexadecameric ribulose-p2 carboxylase from the cyanobacterium synechococcus pcc6301 expressed in escherichia coli. the enzyme has been purified and then crystallized in a number of crystal forms from polyethylene glycol solutions. the best crystals were obtained with enzyme that was first activated with the cofactors co2 and mg2+ in the presence of the tight-binding intermediate analogue, 2'-carboxyarabinitol 1,5-bisphosp ...	1990	2118521
enhancement of chilling tolerance of a cyanobacterium by genetic manipulation of fatty acid desaturation.	the sensitivity (or tolerance) of plants to chilling determines their choice of natural habitat and also limits the worldwide production of crops. although the molecular mechanism for chilling sensitivity has long been debated, no definitive conclusion has so far been reached about its nature. a probable hypothesis, however, is that chilling injury is initiated by phase transition of lipids of cellular membranes, as demonstrated for cyanobacteria, which serve as a model system for the plant cell ...	1990	2118597
genetic analysis of a 9 kda phycocyanin-associated linker polypeptide.	the gene encoding lr9, a 9 kda phycocyanin-associated linker polypeptide, was cloned from the cyanobacterium synechococcus sp. pcc 7002 (agmenellum quadruplicatum pr-6). this gene, termed cpcd, was located immediately 3' to cpcc, a gene which encodes another phycocyanin-associated linker, lr33. mutation of cpcd by insertion led to the loss of lr9 as the only detectable change in phycobilisome composition. cells and isolated phycobilisomes from the cpcd- strain did not detectably differ from the ...	1990	2118804
purification and some properties of the nitrite reductase from the cyanobacterium phormidium laminosum.	assimilatory ferredoxin-nitrite reductase (ec 1.7.7.1, ammonia: ferredoxin oxidoreductase) has been purified 5300-fold with a specific activity of 625 units/mg protein from the filamentous non-heterocystous cyanobacterium phormidium laminosum. the enzyme was soluble and consisted of a single polypeptidic chain of 54 kda. it catalyzed the reduction of nitrite to ammonia using ferredoxin or flavodoxin as electron donor. methyl and benzyl viologens were also effective as electron donors but neither ...	1990	2119228
cloning and nucleotide sequence of the crti gene encoding phytoene dehydrogenase from the cyanobacterium aphanocapsa pcc6714.	the membrane-bound phytoene dehydrogenase (pd) is an enzyme in carotenoid biosynthesis which is essential in all microorganisms and plants containing these colored pigments. despite its key role in the regulation of carotenogenesis, the biochemistry and molecular biology of pd are poorly understood. we have cloned, sequenced and expressed a portion of the pd-encoding gene, crti, from the blue-green algae aphanocapsa pcc6714. the gene codes for a 532-amino acids (aa) protein, with a calculated mr ...	1990	2119326
n-terminal amino acid sequence analysis of small subunits of photosystem i reaction center complex from a thermophilic cyanobacterium, synechococcus elongatus nägeli.	four small subunits (14, 13, 10, and 8 kda) of the photosystem i reaction center complex were isolated from a thermophilic cyanobacterium synechococcus elongatus and their n-terminal amino acid sequences determined. sequence analysis of the 10-kda subunit revealed that the distribution of cysteine residues, cys-x-x-cys-x-x-cys-x-x-x-cys-pro, is characteristic of bacterial-type ferredoxins, and that its partial sequence is highly homologous to that deduced from the chloroplast gene frx a of liver ...	1990	2119498
ordered arrays of the photosystem i reaction centre after reconstitution: projections and surface reliefs of the complex at 2 nm resolution.	we present an electron microscopical analysis of the photosystem i reaction centre, the membrane complex involved in the second light-driven step of photosynthetic electron transfer in plants and cyanobacteria. to this end, ordered two-dimensional arrays were reconstituted from detergent solubilized photosystem i reaction centres and phospholipids, and studied by electron microscopy and digital image processing. small (p1) and large (p3) hexagonal lattices obtained with reaction centres of the t ...	1990	2120036
developmental regulation and spatial pattern of expression of the structural genes for nitrogenase in the cyanobacterium anabaena.	depriving the cyanobacterium anabaena of fixed nitrogen induces the differentiation of heterocysts at intervals along its filaments. to test whether the oxygen-deficient conditions believed to prevail within mature heterocysts are sufficient, in the absence of fixed nitrogen, to elicit the expression of nitrogenase, pnifhdk was fused transcriptionally to luxab (encoding luciferase). expression, monitored from individual cells as light emission, was localized (with a resolution of approximately 1 ...	1990	2120040
dismutation of hydroxylamine to ammonia and nitrite by a novel, membrane-bound enzyme from the cyanobacterium phormidium uncinatum.	extracts from ammonium-grown phototrophic cultures of phormidium uncinatum exhibited a catalytic and stoichiometric formation of nitrite and ammonia from hydrogen peroxide and hydroxylamine. this reaction was due to a novel enzyme (referred to as hydroxylamine dismutase), which was bound to the heavier thylakoid membranes. the enzyme was solubilized from the membranes by detergent treatment and further purified by ion-exchange chromatography. on the basis of inhibitor studies, the involvement of ...	1990	2121280
adenylate cyclase activity in cyanobacteria: activation by ca(2+)-calmodulin and a calmodulin-like activity.	an adenylate cyclase activity was partially characterized in the cyanobacterium anabaena sp. the enzyme activity is found in soluble cell fractions and shows an apparent molecular weight of about 183,400. this adenylate cyclase is activated by ca2+ and bovine brain or spinach calmodulin and it is inhibited by egta and some phenothiazine derivatives. furthermore, anabaena sp. extracts contain a calmodulin-like activity which stimulates bovine brain cyclic amp phosphodiesterase and the anabaena ad ...	1990	2121284
effect of formate on mössbauer parameters of the non-heme iron of ps ii particles of cyanobacteria.	mössbauer spectra were measured for psii particles having an active water-splitting system. the particles were isolated from the thermophilic cyanobacterium synechococcus elongatus enriched in 57fe. the mössbauer resonance absorption spectrum is a superposition of 3 doublets with the following quadrupole splitting and chemical shift: 1, delta = 0.40, delta = 0.85; ii, delta = 1.35, delta = 2.35; iii, delta = 0.25, delta = 1.65. the delta and delta values of doublets i, ii, iii are characteristic ...	1990	2121522
as-1 cyanophage infection inhibits the photosynthetic electron flow of photosystem ii in synechococcus sp. pcc 6301, a cyanobacterium.	in synechococcus sp. cells as-1 cyanophage infection gradually inhibits the photosystem ii mediated photosynthetic electron flow whereas the activity of photosystem i is apparently unaffected by the cyanophage infection. transient fluorescence induction and flash-induced delayed luminescence decay studies revealed that the inhibition may occur at the level of the secondary acceptor, qb of photosystem ii. in addition, the breakdown of d1-protein is inhibited, comparable to dcmu-induced protection ...	1990	2121523
the reaction specificities of the pea and a cyanobacterial thylakoid processing peptidase are similar but not identical.	the thylakoid processing peptidase from the cyanobacterium phormidium laminosum has been extracted from thylakoid membranes by solubilization with triton x-100. its reaction specificity has been compared with the analogous pea peptidase by processing in vitro of radiolabelled wheat and p. laminosum thylakoid lumenal precursor polypeptides. the cyanobacterial polypeptide is processed to the mature size through an intermediate by the p. laminosum peptidase, but to a polypeptide that has a slightly ...	1990	2121534
genes encoding both subunits of phycoerythrocyanin, a light-harvesting biliprotein from the cyanobacterium mastigocladus laminosus.	phycocyanin (pc) and phycoerythrocyanin (pec) are light-harvesting components of the phycobilisome (pbs) from the cyanobacterium mastigocladus laminosus. these two biliproteins are closely related, and show a particularly high degree of sequence homology in the c-terminal part of their beta-subunits. a 198-bp gene fragment encoding this region of pc from m. laminosus was therefore used as a heterologous hybridization probe to identify the genes coding for pec from the same organism. a 1.7-kb hin ...	1990	2121619
expression of the synechocystis sp. strain pcc 6803 trna(glu) gene provides trna for protein and chlorophyll biosynthesis.	in the cyanobacterium synechocystis sp. strain pcc 6803 (synechocystis 6803) delta-aminolevulinic acid (ala), the sole precursor for the synthesis of the porphyrin rings of heme and chlorophyll, is formed from glutamate activated by acylation to trna(glu) (g. p. o'neill, d. m. peterson, a. schön, m. w. chen, and d. söll, j. bacteriol. 170:3810-3816, 1988; s. rieble and s. i. beale, j. biol. chem. 263:8864-8871, 1988). we report here that synechocystis 6803 possesses a single trna(glu) gene which ...	1990	2121711
purification and characterization of a dna polymerase from the cyanobacterium anacystis nidulans r2.	a dna polymerase has been highly purified from anacystis nidulans r2. electrophoretic analysis in sodium dodecyl sulfate-polyacrylamide gels revealed that the final fraction contains three bands of mr 107,000, 93,000, and 51,000, respectively. analysis of purified dna polymerase activity in situ indicates that of the three polypeptides the mr 107,000 species has the catalytic activities. the native molecular weight of the enzyme was estimated by glycerol gradient sedimentation to be 100,000. the ...	1990	2123541
nucleotide sequence of the psba3 gene from the cyanobacterium synechocystis pcc 6803.		1990	2123543
protection from photoinhibition by low temperature in synechocystis 6714 and in chlamydomonas reinhardtii: detection of an intermediary state.	photoinhibition was induced in a cyanobacterium strain, synechocystis 6714, and a green alga, chlamydomonas reinhardtii, by exposing them to light intensities from 1000 to 4000 microe/(m2.s) at various temperatures. the photoinhibition process was followed by measurements of chlorophyll fluorescence and oxygen evolution. during exposure to high light, fluorescent active reaction centers ii became low fluorescent inactive centers. this process involved several reversible and irreversible steps. t ...	1990	2124505
bacterial origin of a chloroplast intron: conserved self-splicing group i introns in cyanobacteria.	a self-splicing group i intron has been found in the gene for a leucine transfer rna in two species of anabaena, a filamentous nitrogen-fixing cyanobacterium. the intron is similar to one that is found at the identical position in the same transfer rna gene of chloroplasts of land plants. because cyanobacteria were the progenitors of chloroplasts, it is likely that group i introns predated the endosymbiotic association of these eubacteria with eukaryotic cells.	1990	2125747
isolation and characterization of hepatotoxic microcystin homologs from the filamentous freshwater cyanobacterium nostoc sp. strain 152.	a strain of the filamentous cyanobacterium nostoc sp. isolated from a lake in finland was found to produce at least nine hepatotoxic peptides with chemical and toxicological properties similar to those of the hepatotoxic hepta- and pentapeptides produced by other cyanobacteria. toxins were isolated and purified by high-performance liquid chromatography. amounts available for five of the purified toxins (p6, p14, p15, p16, and p18) were adequate for high-performance liquid chromatography amino ac ...	1990	2125813
pyruvate-induced stimulation of nitrogenase activity in aulosira fertilissima.	the effect of pyruvate on nitrogenase activity in the n2-fixing cyanobacterium aulosira fertilissima has been studied. addition of 0.01-1.0 mm concentrations of pyruvate to actively n2-fixing cultures stimulated the enzyme activity in light; the maximum stimulation was observed with 0.3 mm pyruvate. there was no detectable stimulation of nitrogenase activity in the dark. addition of pyruvate had no effect on the growth rate. dcmu gradually inhibited nitrogenase activity, but supplementation of 0 ...	1990	2125935
composition of the ferredoxin-nitrite reductase from the cyanobacterium phormidium laminosum.		1990	2125945
physicochemical properties of the exocellular polysaccharide from cyanospira capsulata.	this paper reports on the chemical structure and on some physicochemical properties of a new exopolysaccharide, cc-eps, secreted by a filamentous nitrogen-fixing cyanobacterium, cyanospira capsulata. solution properties of cc-eps were studied with the aim of characterizing the conformational state of the polysaccharide in water and in aqueous salt solution, in view of the peculiar rheological properties. because the molecule has two different uronic acid residues, a variation of ph and/or ionic ...	1990	2127696
heavy metal toxicity in a n2-fixing cyanobacterium, anabaena doliolum: regulation of toxicity by certain environmental factors.	the toxic effects of chromium and tin salts on growth, 14c uptake, heterocyst differentiation, and nitrate reductase, nitrogenase, and glutamine synthetase activities of anabaena doliolum and their regulation by ph, salinity, extracellular metabolites (spent), and organic acids have been studied. the toxicity of the test metals was lowered at alkaline ph and increased at acidic ph. nacl at 20 mm was found to decrease metal toxicity. extracellular metabolites (spent) in a 1:1 ratio (v/v) with fre ...	1990	2129192
characterization of a four-member psba gene family from the cyanobacterium anabaena pcc 7120.	the cyanobacterium anabaena pcc 7120 contains a multigene family that encodes the d1 polypeptide of photosystem ii. this family consists of four members denoted psbai-iv that are each unique but highly homologous. psbaii, iii and iv are more closely related to each other than to psbai. these three copies encode identical polypeptides that differ from the psbai product by 21 amino acids. the transcription initiation site for psbai has been mapped to 64-65 nucleotides upstream from the coding regi ...	1990	2129283
copper-induced expression, cloning, and regulatory studies of the plastocyanin gene from the cyanobacterium synechocystis sp. pcc 6803.	plastocyanin can be detected in synechocystis sp. pcc 6803 when 3 microm copper is added to the growth medium, bg-11. the plastocyanin gene (pete) was cloned from a genomic lambda embl 3 library by screening with the pete gene from anabaena sp. pcc 7937. the synechocystis 6803 pete gene is present as a single copy and, as deduced from the dna sequence, encodes a precursor protein of 126 amino acids. the predicted 29 amino acid transit peptide shows substantial homology to the anabaena 7937 trans ...	1990	2129338
cloning and nucleotide sequence of the psbh gene from cyanobacterium synechocystis 6803.		1990	2129396
sequence conservation among the glucose transporter from the cyanobacterium synechocystis sp. pcc 6803 and mammalian glucose transporters.	synechocystis sp. pcc 6803 is capable of facultative photoheterotrophy with glucose as the sole carbon source. eight mutants that were unable to take up glucose were transformed with plasmids from pooled gene banks of wild-type synechocystis dna prepared in an escherichia coli vector that does not replicate in synechocystis. one mutant (eg216) could be complemented with all gene banks to restore ability for photoheterotrophic growth. one of the gene banks was fractionated into single clones and ...	1990	2129397
photosystem ii characteristics of a constructed synechocystis 6803 mutant lacking synthesis of the d1 polypeptide.	photosystem ii (psii) composition was studied in a mutant of the cyanobacterium synechosystis 6803 in which synthesis of the reaction center polypeptide d1 has been inactivated. the mutant thylakoids had lost also the other reaction center polypeptide d2 and the chlorophyll alpha-binding protein cp47. cytochrome b559 and the chlorophyll alpha-binding protein cp43 accumulated to almost wild-type amounts in mutant thylakoids. also the 33 kda polypeptide involved in water oxidation was present and ...	1990	2129398
cloning of salinity stress-induced genes from the salt-tolerant nitrogen-fixing cyanobacterium anabaena torulosa.	a subtractive hybridization procedure was used to clone genes of the cyanobacterium anabaena torulosa expressed in response to salt stress. the method uses total rna from salt-treated cells, labeled in vitro, as the probe. hybridization to restriction digests of total dna was used for interspecies comparison; the procedure was also successful for isolation of cosmids by colony hybridization, semiquantitative dot blots, and cosmid characterization by southern blotting. analysis of eleven independ ...	1990	2129399
the primary structure of the gamma-subunit of the atpase from synechocystis 6803.	the nucleotide sequence of the gene coding for the f0f1-atpase gamma-subunit (atpc) from the transformable cyanobacterium synchocystis 6083 has been determined. the deduced translation product consists of 314 amino acid residues and is highly homologous (72% identical residues) to the sequences of other cyanobacterial gamma-subunits. the synechocystis 6803 sequence is also homologous to the chloroplast gamma-sequence. like in the other cyanobacterial subunits, only the first of the 3 cysteine re ...	1990	2137788
cloned manganese superoxide dismutase reduces oxidative stress in escherichia coli and anacystis nidulans.	the mn superoxide dismutase gene of escherichia coli was subcloned into the e. coli-anacystis nidulans shuttle vector psg111 to make the plasmid pmyg1. transformation of e. coli hb101 with pmyg1 resulted in a 6-fold increase in superoxide dismutase activity. there was also induction of mn superoxide dismutase in the transformants upon exposure to paraquat, as evidenced by dramatically increased levels of the mn superoxide dismutase polypeptide in cytoplasmic extracts and a 16-fold further increa ...	1990	2157207
use of a conditionally lethal gene in anabaena sp. strain pcc 7120 to select for double recombinants and to entrap insertion sequences.	use of the sacb gene (j. l. ried and a. collmer, gene 57:239-246, 1987) provides a simple, effective, positive selection for double recombinants in anabaena sp. strain pcc 7120, a filamentous cyanobacterium. this gene, which encodes the secretory levansucrase of bacillus subtilis, was inserted into the vector portion of a suicide plasmid bearing a mutant version of a chromosomal gene. cells of colonies in which such a plasmid had integrated into the anabaena chromosome through single recombinati ...	1990	2160938
identification of a periplasmic c-type cytochrome as electron donor to the plasma membrane-bound cytochrome oxidase of the cyanobacterium nostoc mac.	photoautotrophically grown cyanobacterium nostoc sp. strain mac (pcc 8009) released up to about 10 nmol of a c-type cytochrome per ml packed cells after treatment with edta under conditions that left the plasma membrane absolutely intact as judged from the absence of cytosolic proteins in the supernatant. spectra of the ascorbate reduced cytochrome revealed peaks at 553, 522 and 416 nm. the protein was purified to an a-553/a-275 ratio of 0.8. midpoint potential (at ph 7), isoelectric point and a ...	1990	2162667
light-dependent delta mu na-generation and utilization in the marine cyanobacterium oscillatoria brevis.	light-dependent na+ and h+ transports, membrane potential (delta psi) and motility have been studied in the cells of the marine cyanobacterium oscillatoria brevis. in the presence of a protonophorous uncoupler, carbonyl cyanide-m-chlorophenylhydrazone, the intracellular na+ level is shown to increase in the dark and decrease in the light. the na+/h+ antiporter, monensin, stimulates the dark cccp-dependent [na+]in increase and abolishes the light-dependent [na+]in decrease. na+ ions are necessary ...	1990	2171990
proton-linked sugar transport systems in bacteria.	the cell membranes of various bacteria contain proton-linked transport systems for d-xylose, l-arabinose, d-galactose, d-glucose, l-rhamnose, l-fucose, lactose, and melibiose. the melibiose transporter of e. coli is linked to both na+ and h+ translocation. the substrate and inhibitor specificities of the monosaccharide transporters are described. by locating, cloning, and sequencing the genes encoding the sugar/h+ transporters in e. coli, the primary sequences of the transport proteins have been ...	1990	2172229
tyrosine radicals in photosystem ii and related model compounds. characterization by isotopic labeling and epr spectroscopy.	deuteration at selected positions on the phenol ring and at the beta-methylene carbon for the yd.tyrosine radical in photosystem ii in the cyanobacterium synechocystis 6803 was achieved by growing the organism under conditions in which it is a functional aromatic amino acid auxotroph (barry, b. a., and babcock, g. t. (1987) proc. natl. acad. sci. u.s.a. 84, 7099-7103). a series of model tyrosine radicals, also deuterated at specific sites on the aromatic ring and the methylene group, was generat ...	1990	2173697
pka values and partition coefficients of nitroxide spin probes for membrane bioenergetics measurements.	knowledge of pka's is necessary to calculate intracellular/intravesicular ph values from nitroxide accumulation in cells or vesicles as detected with electron spin resonance (esr) spectroscopy. pka values were confirmed in lipid vesicles of known internal ph. to help select probes that do not accumulate in lipid membranes, octanol/buffer partition coefficients of uncharged nitroxides were determined. as an application of selected probes, ph gradients and internal aqueous volumes were analyzed in ...	1990	2175281
separation of phycobiliprotein subunits by reverse-phase high-pressure liquid chromatography.	baseline separation of subunits of diverse phycobiliproteins was achieved by a reverse-phase hplc gradient method with a c4 large-pore column and a solvent system consisting of 0.1% trifluoroacetic acid (tfa) in water and 0.1% tfa in 2:1 (v/v) acetonitrile:isopropanol. the procedure was successfully applied to cyanobacterial allophycocyanin and c-phycocyanins, an unusual phycocyanin from a marine cyanobacterium, red algal b- and r-phycoerythrins, and a cryptomonad phycoerythrin. the subunit size ...	1990	2221378
nucleotide sequence and expression of a deep-sea ribulose-1,5-bisphosphate carboxylase gene cloned from a chemoautotrophic bacterial endosymbiont.	the gene coding for ribulose-1,5-bisphosphate carboxylase [rubisco; 3-phospho-d-glycerate carboxy-lyase (dimerizing), ec 4.1.1.39] was cloned from a sulfur-oxidizing chemoautotrophic bacterium that resides as an endosymbiont within the gill tissues of alvinoconcha hessleri, a gastropod inhabiting deep-sea hydrothermal vents. nucleotide sequence analysis of the cloned fragment demonstrated that the genes encoding the large (rbcl) and small (rbcs) subunits of the symbiont rubisco were organized si ...	1990	2247456
pathophysiologic effects of anatoxin-a(s) in anaesthetized rats: the influence of atropine and artificial respiration.	the pathophysiologic effects of anatoxin-a(s) from the cyanobacterium anabaena flos-aquae nrc-525-17 were investigated in anaesthetized adult male sprague dawley rats given the toxin by continuous intravenous infusion until death. rats (n = 6) pretreated with atropine sulfate (50 mg/kg) intraperitoneally survived significantly longer (p less than 0.05) than non-atropinized rats (n = 6), suggesting that the muscarinic effects of anatoxin-a(s) were important in the lethal syndrome. in contrast to ...	1990	2255668
acute toxicity of the natural algicide, cyanobacterin, to daphnia magna.	cyanobacterin is a potent, photosynthetic inhibitor produced as a secondary metabolite by the filamentous, freshwater cyanobacterium scytonema hofmanni. with a spectrum of activity encompassing species of cyanobacteria and eucaryotic algae as well as higher plants, cyanobacterin might be utilized as a commercial algicide for algae waterbloom control. as a component of the preliminary environmental risk/hazard evaluation of this proposed application, the acute toxicity of cyanobacterin to the pla ...	1990	2276362