Publications

structural basis of murein peptide specificity of a gamma-d-glutamyl-l-diamino acid endopeptidase.	the crystal structures of two homologous endopeptidases from cyanobacteria anabaena variabilis and nostoc punctiforme were determined at 1.05 and 1.60 a resolution, respectively, and contain a bacterial sh3-like domain (sh3b) and a ubiquitous cell-wall-associated nlpc/p60 (or chap) cysteine peptidase domain. the nlpc/p60 domain is a primitive, papain-like peptidase in the ca clan of cysteine peptidases with a cys126/his176/his188 catalytic triad and a conserved catalytic core. we deduced from st ...	2009	19217401
solid-phase/supercritical-fluid extraction for liquid chromatography of phenolic compounds in freshwater microalgae and selected cyanobacterial species.	in the present paper a new extraction technique based on the combination of solid-phase/supercritical-fluid extraction (spe/sfe) with subsequent reversed-phase hplc is described. the spe/sfe extractor was originally constructed from spe-cartridge incorporated into the sfe extraction cell. selected groups of benzoic acid derivatives (p-hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acid), hydroxybenzaldehydes (4-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde) and cinnamic acid d ...	2009	19111311
structure-function, stability, and chemical modification of the cyanobacterial cytochrome b6f complex from nostoc sp. pcc 7120.	the crystal structure of the cyanobacterial cytochrome b(6)f complex has previously been solved to 3.0-a resolution using the thermophilic mastigocladus laminosus whose genome has not been sequenced. several unicellular cyanobacteria, whose genomes have been sequenced and are tractable for mutagenesis, do not yield b(6)f complex in an intact dimeric state with significant electron transport activity. the genome of nostoc sp. pcc 7120 has been sequenced and is closer phylogenetically to m. lamino ...	2009	19189962
a comparative genomics approach to understanding the biosynthesis of the sunscreen scytonemin in cyanobacteria.	the extracellular sunscreen scytonemin is the most common and widespread indole-alkaloid among cyanobacteria. previous research using the cyanobacterium nostoc punctiforme atcc 29133 revealed a unique 18-gene cluster (npr1276 to npr1259 in the n. punctiforme genome) involved in the biosynthesis of scytonemin. we provide further genomic characterization of these genes in n. punctiforme and extend it to homologous regions in other cyanobacteria.	2009	19630972
electron transfer protein complexes in the thylakoid membranes of heterocysts from the cyanobacterium nostoc punctiforme.	filamentous, heterocystous cyanobacteria are capable of nitrogen fixation and photoautotrophic growth. nitrogen fixation takes place in heterocysts that differentiate as a result of nitrogen starvation. heterocysts uphold a microoxic environment to avoid inactivation of nitrogenase, e.g. by downregulation of oxygenic photosynthesis. the atp and reductant requirement for the nitrogenase reaction is considered to depend on photosystem i, but little is known about the organization of energy convert ...	2009	19366613
nmr resonance assignment of dnae intein from nostoc punctiforme.	dnae intein from nostoc punctiforme (npu) is one of naturally occurring split inteins, which has robust protein splicing activity. highly efficient trans-splicing activity of npudnae intein could widen various biotechnological applications. however, structural basis of the efficient protein splicing activity is poorly understood. as a first step toward better understanding of protein trans-splicing mechanism, we present the backbone and side-chain resonance assignments of a single chain variant ...	2009	19636943
structure of the biliverdin radical intermediate in phycocyanobilin:ferredoxin oxidoreductase identified by high-field epr and dft.	the cyanobacterial enzyme phycocyanobilin:ferredoxin oxidoreductase (pcya) catalyzes the two-step four-electron reduction of biliverdin ixalpha to phycocyanobilin, the precursor of biliprotein chromophores found in phycobilisomes. it is known that catalysis proceeds via paramagnetic radical intermediates, but the structure of these intermediates and the transfer pathways for the four protons involved are not known. in this study, high-field electron paramagnetic resonance (epr) spectroscopy of f ...	2009	19159240
site-specific two-color protein labeling for fret studies using split inteins.	fluorescence resonance energy transfer (fret) is an ideal tool for studying protein conformational changes and dynamics. strategies to specifically label proteins with multiple colors at structurally important sites, a prerequisite for such studies, however, need to be devised on a protein-by-protein basis. here we describe a simple yet widely applicable two-color site-specific protein labeling method utilizing npu dnae split intein.	2009	19645470
assessment of sampling strategies for gas chromatography-mass spectrometry (gc-ms) based metabolomics of cyanobacteria.	metabolomics is the comprehensive analysis of the small molecules that compose an organism's metabolism. the main limiting step in microbial metabolomics is the requirement for fast and efficient separation of microbes from the culture medium under conditions in which metabolism is rapidly halted. in this article we compare three different sampling strategies, quenching, filtering, and centrifugation, for arresting the metabolic activities of two morphologically diverse cyanobacteria, the unicel ...	2009	19631594
hypocholesterolemic effect of nostoc commune var. sphaeroides kützing, an edible blue-green alga.	intake of an edible blue-green alga nostoc commune var. sphaeroides kützing (n. commune) has been shown to lower plasma total cholesterol concentration, but the mechanisms behind the hypocholesterolemic effect have not been elucidated.	2009	19404563
screening for acetylcholinesterase inhibitory activity in cyanobacteria of the genus nostoc.	fifty-four cyanobacterial strains of the genus nostoc from different habitats were screened for acetylcholinesterase inhibitory activity. water-methanolic extracts from freeze-dried biomasses were tested for inhibitory activity using ellman's spectrophotometric method. acetylcholinesterase inhibitory activity higher than 90% was found in the crude extracts of nostoc sp. str. lukesova 27/97 and nostoc ellipsosporum rabenh. str. lukesova 51/91. extracts from nostoc ellipsosporum str. lukesova 52/9 ...	2009	18951237
role of ntca, a cyanobacterial global nitrogen regulator, in the regulation of sucrose metabolism gene expression in anabaena sp. pcc 7120.	in the heterocyst-forming cyanobacterium anabaena sp. pcc 7120 (also known as nostoc sp. pcc 7120), it has been shown that spsb and susa, the genes coding for proteins related to sucrose synthesis and cleavage, respectively, exhibit converse expression regarding the nitrogen source. in the nitrogen-fixing filament, spsb expression is mostly localized to the heterocysts and susa is only expressed in vegetative cells. the aim of this work was to investigate the participation of ntca, a global nitr ...	2009	19082579
characterization of a novel debranching enzyme from nostoc punctiforme possessing a high specificity for long branched chains.	a novel debranching enzyme from nostoc punctiforme pcc73102 (npde) exhibits hydrolysis activity toward both alpha-(1,6)- and alpha-(1,4)-glucosidic linkages. the action patterns of npde revealed that branched chains are released first, and the resulting maltooligosaccharides are then hydrolyzed. analysis of the reaction with maltooligosaccharide substrates labeled with (14)c-glucose at the reducing end shows that npde specifically liberates glucose from the reducing end. kinetic analyses showed ...	2009	19010304
the 2a resolution crystal structure of hetl, a pentapeptide repeat protein involved in regulation of heterocyst differentiation in the cyanobacterium nostoc sp. strain pcc 7120.	the hetl gene from the cyanobacterium nostoc sp. pcc 7120 encodes a 237 amino acid protein (25.6kda) containing 40 predicted tandem pentapeptide repeats. nostoc sp. pcc 7120 is a filamentous cyanobacterium that forms heterocysts, specialized cells capable of fixing atmospheric n(2) during nitrogen starvation in its aqueous environment. under these conditions, heterocysts occur in a regular pattern of approximately one out of every 10-15 vegetative cells. heterocyst differentiation is highly regu ...	2009	18952182
gobase: an organelle genome database.	the organelle genome database gobase, now in its 21st release (june 2008), contains all published mitochondrion-encoded sequences (approximately 913,000) and chloroplast-encoded sequences (approximately 250,000) from a wide range of eukaryotic taxa. for all sequences, information on related genes, exons, introns, gene products and taxonomy is available, as well as selected genome maps and rna secondary structures. recent major enhancements to database functionality include: (i) addition of an in ...	2009	18953030
an evaluation of four phylogenetic markers in nostoc: implications for cyanobacterial phylogenetic studies at the intrageneric level.	the success of some phylogenetic markers in cyanobacteria owes to the design of cyanobacteria-specific primers, but a few studies have directly investigated the evolution "behavior" of the loci. in this study, we performed a case study in nostoc to evaluate rpoc1, hetr, rbclx, and 16s rrna-trna(ile)-trna(ala)-23s rrna internal transcribed spacer (its) as phylogenetic markers. the results indicated that the gene trees of these loci are not congruent with the phylogeny based on 16s rrna gene. the ...	2009	18972163
the role of the c-terminal region of cyanophycin synthetase from nostoc ellipsosporum ne1 in its enzymatic activity and thermostability: a key function of glu(856).	the biosynthesis of cyanophycin granule polypeptides is catalyzed by cyanophycin synthetase, cpha. in this study, the role of the c-terminal region of cpha from nostoc ellipsosporum ne1, cpha(ne1), was analyzed using a tailor-made c-terminus truncated library. the expression level of truncated cpha(ne1) in e. coli depended on the stop codons that were used. the expression vector that had the amber stop codon tag produced more than twice amount of cpha(ne1) as a vector that contained the ochre co ...	2009	18977318
bioinformatic and expression analyses of genes mediating zinc homeostasis in nostoc punctiforme.	zinc homeostasis was investigated in nostoc punctiforme. cell tolerance to zn(2+) over 14 days showed that zncl(2) levels above 22 microm significantly reduced cell viability. after 3 days in 22 microm zncl(2), ca. 12% of the zn(2+) was in an edta-resistant component, suggesting an intracellular localization. zinquin fluorescence was detected within cells exposed to concentrations up to 37 microm relative to 0 microm treatment. radiolabeled (65)zn showed zn(2+) uptake increased over a 3-day peri ...	2009	19011078
quantitative overview of n2 fixation in nostoc punctiforme atcc 29133 through cellular enrichments and itraq shotgun proteomics.	nostoc punctiforme atcc 29133 is a photoautotrophic cyanobacterium with the capacity to fix atmospheric n 2. its ability to mediate this process is similar to that described for nostoc sp. pcc 7120, where vegetative cells differentiate into heterocysts. quantitative proteomic investigations at both the filament level and the heterocyst level are presented using isobaric tagging technology (itraq), with 721 proteins at the 95% confidence interval quantified across both studies. observations from ...	2009	19012430
molecular characterization and the effect of salinity on cyanobacterial diversity in the rice fields of eastern uttar pradesh, india.	salinity is known to affect almost half of the world's irrigated lands, especially rice fields. furthermore, cyanobacteria, one of the critical inhabitants of rice fields have been characterized at molecular level from many different geographical locations. this study, for the first time, has examined the molecular diversity of cyanobacteria inhabiting indian rice fields which experience various levels of salinity.	2009	19344531
new insights into the role of fur proteins: furb (all2473) from anabaena protects dna and increases cell survival under oxidative stress.	fur (ferric uptake regulator) is a prokaryotic transcriptional regulator that controls a large number of genes mainly related to iron metabolism. several fur homologues with different physiological roles are frequently found in the same organism. the genome of the filamentous cyanobacterium anabaena (nostoc) sp. pcc 7120 codes for three different fur genes. fura is an essential protein involved in iron homoeostasis that also modulates dinitrogen fixation. fura interacts with haem, impairing its ...	2009	18945213
diversity of 23s rrna genes within individual prokaryotic genomes.	the concept of ribosomal constraints on rrna genes is deduced primarily based on the comparison of consensus rrna sequences between closely related species, but recent advances in whole-genome sequencing allow evaluation of this concept within organisms with multiple rrna operons.	2009	19415112
gene expression patterns associated with the biosynthesis of the sunscreen scytonemin in nostoc punctiforme atcc 29133 in response to uva radiation.	under exposure to uv radiation, some cyanobacteria synthesize sunscreen compounds. scytonemin is a heterocyclic indole-alkaloid sunscreen, the synthesis of which is induced upon exposure to uva (long-wavelength uv) radiation. we previously identified and characterized an 18-gene cluster associated with scytonemin biosynthesis in the cyanobacterium nostoc punctiforme atcc 29133; we now report on the expression response of these genes to a step-up shift in uva exposure. using quantitative pcr on c ...	2009	19429608
accumulation of exopolysaccharides in liquid suspension culture of nostoc flagelliforme cells.	the liquid suspension culture of dissociated nostoc flagelliforme cells was investigated. it was found that the growth rate of n. flagelliforme cells and the accumulation of exopolysaccharides (eps) increased prominently when nano(3) and kh(2)po(4) were added in the liquid bg-11culture medium though phosphate had little effect on eps yield for specific mass of cells. n. flagelliforme cells grew well at 25 degrees c and neutral ph, however, a lower or higher temperature and weak alkaline can prom ...	2010	19018481
two alternative starter modules for the non-ribosomal biosynthesis of specific anabaenopeptin variants in anabaena (cyanobacteria).	anabaenopeptins are a diverse family of cyclic hexapeptide protease inhibitors produced by cyanobacteria that contain a conserved ureido bond and d-lys moiety. here we demonstrate that anabaenopeptins are assembled on a nonribosomal peptide synthetase enzyme complex encoded by a 32 kb apt gene cluster in the cyanobacterium anabaena sp. strain 90. surprisingly, the gene cluster encoded two alternative starter modules organized in separate bimodular proteins. the starter modules display high subst ...	2010	20338518
enlarging clinical spectrum of fals with tardbp gene mutations: s393l variant in an italian family showing phenotypic variability and relevance for genetic counselling.	the present study was aimed to enlarge the italian als sample analysed for tardbp gene mutations.	2010	19714537
design and characterization of molecular tools for a synthetic biology approach towards developing cyanobacterial biotechnology.	cyanobacteria are suitable for sustainable, solar-powered biotechnological applications. synthetic biology connects biology with computational design and an engineering perspective, but requires efficient tools and information about the function of biological parts and systems. to enable the development of cyanobacterial synthetic biology, several molecular tools were developed and characterized: (i) a broad-host-range biobrick shuttle vector, ppmqak1, was constructed and confirmed to replicate ...	2010	20236988
bacterial diversity, pigments and nitrogen fixation of biological desert crusts from the sultanate of oman.	biological desert crusts are relatively common in the arid deserts of the sultanate of oman; however, little is known about their microbial community composition and role in soil fertilization. we compared three crusts from geographically different locations for their soil texture, bacterial community structure, pigment composition and nitrogenase activity. the crusts were growing on alkaline (ph 7.6-8.7) loamy sand and silty loam soils. microscopically, microcoleus vaginatus was the most abunda ...	2010	20298501
comparative toxicity of bentazon and molinate on growth, photosynthetic pigments, photosynthesis, and respiration of the portuguese ricefield cyanobacterium nostoc muscorum.	bentazon and molinate are selective herbicides recommended for integrated weed management in rice. their toxicity on growth and some biochemical and physiological parameters of nostoc muscorum, an abundant cyanobacterium in portuguese rice fields, was evaluated under laboratory conditions during time- and concentration-dependent exposure for 72 h. results showed that toxic concentrations (0.75-2 mm) of both herbicides have pleiotropic effects on the cyanobacterium. molinate was more toxic than b ...	2010	19319991
synthesis, properties, and applications of diazotrifluropropanoyl-containing photoactive analogs of farnesyl diphosphate containing modified linkages for enhanced stability.	photoactive analogs of farnesyl diphosphate (fpp) are useful probes in studies of enzymes that employ this molecule as a substrate. here, we describe the preparation and properties of two new fpp analogs that contain diazotrifluoropropanoyl photophores linked to geranyl diphosphate via amide or ester linkages. the amide-linked analog (3) was synthesized in 32p-labeled form from geraniol in seven steps. experiments with saccharomyces cerevisiae protein farnesyltransferase (scpftase) showed that 3 ...	2010	19954434
characterization of a microcystin and detection of microcystin synthetase genes from a brazilian isolate of nostoc.	a nostocalean nitrogen-fixing cyanobacterium isolated from an eutrophic freshwater reservoir located in piracicaba, são paulo, brazil, was evaluated for the production of hepatotoxic cyclic heptapeptides, microcystins. morphologically this new cyanobacterium strain appears closest to nostoc, however, in the phylogenetic analysis of 16s rrna gene it falls into a highly stable cluster distantly only related to the typical nostoc cluster. extracts of nostoc sp. cena88 cultured cells, investigated u ...	2010	20003912
cala, a cyanobacterial abrb protein, interacts with the upstream region of hypc and acts as a repressor of its transcription in the cyanobacterium nostoc sp. strain pcc 7120.	the filamentous, heterocystous, nitrogen-fixing cyanobacterium nostoc sp. strain pcc 7120 may contain, depending on growth conditions, up to two hydrogenases directly involved in hydrogen metabolism. hypc is one out of at least seven auxiliary gene products required for synthesis of a functional hydrogenase, specifically involved in the maturation of the large subunit. in this study we present a protein, cala (alr0946 in the genome), belonging to the transcription regulator family abrb, which in ...	2010	20023111
excitation energy transfer to photosystem i in filaments and heterocysts of nostoc punctiforme.	cyanobacteria adapt to varying light conditions by controlling the amount of excitation energy to the photosystems. on the minute time scale this leads to redirection of the excitation energy, usually referred to as state transitions, which involves movement of the phycobilisomes. we have studied short-term light adaptation in isolated heterocysts and intact filaments from the cyanobacterium nostoc punctiforme atcc 29133. in n. punctiforme vegetative cells differentiate into heterocysts where ni ...	2010	20036211
expansion of ribosomally produced natural products: a nitrile hydratase- and nif11-related precursor family.	a new family of natural products has been described in which cysteine, serine and threonine from ribosomally-produced peptides are converted to thiazoles, oxazoles and methyloxazoles, respectively. these metabolites and their biosynthetic gene clusters are now referred to as thiazole/oxazole-modified microcins (tomm). as exemplified by microcin b17 and streptolysin s, tomm precursors contain an n-terminal leader sequence and c-terminal core peptide. the leader sequence contains binding sites for ...	2010	20500830
use of protein trans-splicing to produce active and segmentally (2)h, (15)n labeled mannuronan c5-epimerase alge4.	alginate epimerases are large multidomain proteins capable of epimerising c5 on beta-d-mannuronic acid (m) turning it into alpha-l-guluronic acid (g) in a polymeric alginate. azotobacter vinelandii secretes a family of seven epimerases, each of which is capable of producing alginates with characteristic g distribution patterns. all seven epimerases consist of two types of modules, denoted a and r, in varying numbers. attempts to study these enzymes with solution-state nmr are hampered by their s ...	2010	20552686
is nostoc h-nox a no sensor or redox switch?	nostoc sp. (ns) h-nox is a heme protein found in symbiotic cyanobacteria, which has approximately 35% sequence identity and high structural homology to the beta subunit of soluble guanylyl cyclase (sgc), suggesting a no sensing function. however, uv-vis, epr, nir mcd, and ligand binding experiments with ferrous and ferric ns h-nox indicate significant functional differences between ns h-nox and sgc. (1) after no binding to sgc, the proximal histidine dissociates from the heme iron, causing a con ...	2010	20572679
detection of the neurotoxin bmaa within cyanobacteria isolated from freshwater in china.	the cyanobacterial neurotoxin, beta-n-methylamino-l-alanine (bmaa), has been suggested as an important environmental factor for neurodegenerative disease such as amyotrophic lateral sclerosis- parkinsonism dementia complex (als/pdc) in guam. bmaa was detected within the majority of cyanobacterial isolates surveyed in both free and symbiotic cyanobacteria, living in freshwater as well as marine environments. in this study, we report two methods using liquid chromatography-electrospray ionization- ...	2010	19822166
primary screening of the bioactivity of brackishwater cyanobacteria: toxicity of crude extracts to artemia salina larvae and paracentrotus lividus embryos.	cyanobacteria are a diverse group of gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, plants, microalgae, fungi, bacteria, viruses and cell lines. the aim of this study was to assess the toxic effects of aqueous, methanolic and hexane crude extracts of benthic and picoplanktonic cyanobacteria isolated from estuarine environments, towards the nauplii of the brine shrimp artemia salina and embryos of the sea urchin p ...	2010	20411110
a novel alpha-amylase from the cyanobacterium nostoc sp. pcc 7119.	little information is yet available on the alpha-amylases of cyanobacteria. here, the presence of an alpha-amylase in the cyanobacterium nostoc sp. pcc 7119 is first demonstrated. a gene (amy1) encoding a cytoplasmic alpha-amylase (amy1) protein has been identified, cloned, and overexpressed in escherichia coli cells. the recombinant protein is a 56.7-kda monomer, which has been purified to electrophoretic homogeneity by affinity chromatography. the substrate specificity and end product analyses ...	2010	19756583
[expression, purification and activity determination of cyanovirin-n].	cyanovirin-n (cvn) is an 11 kda anti-hiv protein originally isolated from extracts of a cyanobacterium, nostoc ellipsosporum. the protein binds with high affinity to the viral envelope glycoprotein gp120 and irreversibly inactivates diverse hiv strains. a fusion gene consisting of cvn, sumo and 6xhis tag was synthesized by pcr according to the codon bias of escherichia coli. the fusion protein is expressed in the cytoplasm of e. coli in a soluble form and up to 28% of the total protein. the reco ...	2010	20575444
cytotoxicity and secondary metabolites production in terrestrial nostoc strains, originating from different climatic/geographic regions and habitats: is their cytotoxicity environmentally dependent?	extensive selection of cyanobacterial strains (82 isolates) belonging to the genus nostoc, isolated from different climatic regions and habitats, were screened for both their secondary metabolite content and their cytotoxic effects to mammalian cell lines. the overall occurrence of cytotoxicity was found to be 33%, which corresponds with previously published data. however, the frequency differs significantly among strains, which originate from different climatic regions and microsites (particula ...	2010	20082446
occurrence of brackish water phytoplankton species at a closed coral reef in nansha islands, south china sea.	the phytoplankton assemblage of zhubi reef, a closed coral reef in nansha islands (south china sea, scs) was studied in june 2007. a total of 92 species belonging to 53 genera and four phyla have been identified. the dominant taxa in the lagoon were the diatom chaetoceros and cyanobacteria nostoc and microcystis, while in reef flats were cyanobacteria trichodesmium erythraeum, dinoflagellates gymnodinium and prorocentrum. the species richness and diversity were consistently lower in the lagoon t ...	2010	20656304
post-translational modifications of integral membrane proteins resolved by top-down fourier transform mass spectrometry with collisionally activated dissociation.	integral membrane proteins remain a challenge to proteomics because they contain domains with physicochemical properties poorly suited to today's bottom-up protocols. these transmembrane regions may potentially contain post-translational modifications of functional significance, and thus development of protocols for improved coverage in these domains is important. one way to achieve this goal is by using top-down mass spectrometry whereby the intact protein is subjected to mass spectrometry and ...	2010	20093275
signature proteins for the major clades of cyanobacteria.	the phylogeny and taxonomy of cyanobacteria is currently poorly understood due to paucity of reliable markers for identification and circumscription of its major clades.	2010	20100331
complementary uv-absorption of mycosporine-like amino acids and scytonemin is responsible for the uv-insensitivity of photosynthesis in nostoc flagelliforme.	mycosporine-like amino acids (maas) and scytonemin are uv-screening compounds that have presumably appeared early in the history of life and are widespread in cyanobacteria. natural colonies of the uv-insensitive nostoc flagelliforme were found to be especially rich in maas (32.1 mg g dw(-1)), concentrated in the glycan sheath together with scytonemin. maas are present in the form of oligosaccharide-linked molecules. photosystem ii activity, measured using pam fluorescence and oxygen evolution, ...	2010	20161974
the genetic and molecular basis for sunscreen biosynthesis in cyanobacteria.	ultraviolet uv-a and uv-b radiation is harmful to living systems, causing damage to biological macromolecules. an important strategy for dealing with uv exposure is the biosynthesis of small-molecule sunscreens. among such metabolites, the mycosporine and mycosporine-like amino acids (maas) are remarkable for their wide phylogenetic distribution and their unique chemical structures. here, we report the identification of a maa biosynthetic gene cluster in a cyanobacterium and the discovery of ana ...	2010	20813918
molecular mechanisms of microcystin toxicity in animal cells.	microcystins (mc) are potent hepatotoxins produced by the cyanobacteria of the genera planktothrix, microcystis, aphanizomenon, nostoc and anabaena. these cyclic heptapeptides have strong affinity to serine/threonine protein phosphatases (pps) thereby acting as an inhibitor of this group of enzymes. through this interaction a cascade of events responsible for the mc cytotoxic and genotoxic effects in animal cells may take place. moreover mc induces oxidative stress in animal cells and together w ...	2010	20162015
nostotrebin 6, a bis(cyclopentenedione) with cholinesterase inhibitory activity isolated from nostoc sp. str. lukesová 27/97.	nostotrebin 6, a new polyphenolic compound with a fully substituted 2,2'-bis(cyclopent-4-en-1,3-dione) skeleton, was isolated from a methanolic extract of the cyanobacterial strain nostoc sp. str. lukesová 27/97. the structure of this compound was determined using x-ray crystallography and further supported by nmr, ir spectroscopy, and ms. nostotrebin 6 is an s-parabolic i-parabolic noncompetitive inhibitor of acetylcholinesterase (ic(50) = 5.5 microm) and an s-parabolic i-parabolic mixed inhibi ...	2010	20233015
cyanobacteriochrome ccas regulates phycoerythrin accumulation in nostoc punctiforme, a group ii chromatic adapter.	responding to green and red light, certain cyanobacteria change the composition of their light-harvesting pigments, phycoerythrin (pe) and phycocyanin (pc). although this phenomenon-complementary chromatic adaptation-is well known, the green light-sensing mechanism for pe accumulation is unclear. the filamentous cyanobacterium nostoc punctiforme atcc 29133 (n. punctiforme) regulates pe synthesis in response to green and red light (group ii chromatic adaptation). we disrupted the green/red-percei ...	2010	20404166
exploiting cyanobacterial p450 pathways.	cytochrome p450s are hemoprotein oxygenases involved in natural product synthetic pathways. cyanobacteria are oxygenic photosynthetic microorganisms and are considered a rich source of natural products, and are now known to harbour p450s. a variety of cyanobacterial species have been found to contain multiple copies of p450s in their genomes, and over 100 have been predicted. interestingly, some are membrane-bound as in eukaryotes, as opposed to cytoplasmic in bacteria. furthermore, they can com ...	2010	20299274
computational analysis of lexa regulons in cyanobacteria.	the transcription factor lexa plays an important role in the sos response in escherichia coli and many other bacterial species studied. although the lexa gene is encoded in almost every bacterial group with a wide range of evolutionary distances, its precise functions in each group/species are largely unknown. more recently, it has been shown that lexa genes in two cyanobacterial genomes nostoc sp. pcc 7120 and synechocystis sp. pcc 6803 might have distinct functions other than the regulation of ...	2010	20920248
molecular cloning and characterization of maltooligosyltrehalose synthase gene from nostoc flagelliforme.	a genomic dna fragment encoding a putative maltooligosyltrehalose synthase (nfmts) for trehalose biosynthesis was cloned by the degenerate primer-pcr from cyanobacterium nostoc flagelliforme. the orf of nfmts was 2,799 bp in length and encoded 933 amino acid residues constituting a 106.6 kda protein. the deduced amino acid sequence of nfmts contained 4 regions highly conserved for mtss. by expression of nfmts in e. coli, it was demonstrated that the recombinant protein catalyzed the conversion o ...	2010	20372031
cala, a cyabrb protein, binds to the upstream region of ftsz and is down-regulated in heterocysts in anabaena sp. pcc 7120.	a protein of cyabrb family of regulators, alr0946 (cala), was identified by dna affinity chromatography using dna fragments from the promoter region of ftsz in anabaena/nostoc sp. pcc 7120. electrophoretic mobility shift assays showed that the protein could bind to upstream regions of ftsz (as biotin-labeled dna fragments) and that the binding was inhibited by the same dna fragments and a fragment upstream of hetc but not by 3 fragments upstream of glna, hetr or ntca. both transcriptional fusion ...	2010	20405108
relationship between color and pigment production in two stone biofilm-forming cyanobacteria (nostoc sp. pcc 9104 and nostoc sp. pcc 9025).	previous studies have provided evidence that color measurements enable on site quantification of superficial biofilms, thereby avoiding the need for sampling. in the present study, the efficiency of color measurements to evaluate to what extent pigment production is affected by environmental parameters such as light intensity, combined nitrogen and nutrient availability, was tested with two cyanobacteria, nostoc sp. strains pcc 9104 and pcc 9025, which form biofilms on stone. both strains were a ...	2010	20425659
allelopathic effects of water hyacinth [eichhornia crassipes].	eichhornia crassipes (mart) solms is an invasive weed known to out-compete native plants and negatively affect microbes including phytoplankton. the spread and population density of e. crassipes will be favored by global warming. the aim here was to identify compounds that underlie the effects on microbes. the entire plant of e. crassipes was collected from el zomor canal, river nile (egypt), washed clean, then air dried. plant tissue was extracted three times with methanol and fractionated by t ...	2010	20949048
hideo iwai. interview by daniela ruffell.		2010	20450913
cyanobacterial heterocysts.	many multicellular cyanobacteria produce specialized nitrogen-fixing heterocysts. during diazotrophic growth of the model organism anabaena (nostoc) sp. strain pcc 7120, a regulated developmental pattern of single heterocysts separated by about 10 to 20 photosynthetic vegetative cells is maintained along filaments. heterocyst structure and metabolic activity function together to accommodate the oxygen-sensitive process of nitrogen fixation. this article focuses on recent research on heterocyst d ...	2010	20452939
host selection of symbiotic cyanobacteria in 31 species of the australian cycad genus: macrozamia (zamiaceae).	the nitrogen-fixing cyanobacterium nostoc is a commonly occurring terrestrial and aquatic cyanobacterium often found in symbiosis with a wide range of plant, algal, and fungal species. we investigated the diversity of cyanobacterial species occurring within the coralloid roots of different macrozamia cycad species at diverse locations throughout australia. in all, 74 coralloid root samples were processed and 56 endosymbiotic cyanobacteria were cultured. dna was isolated from unialgal cultures an ...	2010	20459320
structure of cinaciguat (bay 58-2667) bound to nostoc h-nox domain reveals insights into heme-mimetic activation of the soluble guanylyl cyclase.	heme is a vital molecule for all life forms with heme being capable of assisting in catalysis, binding ligands, and undergoing redox changes. heme-related dysfunction can lead to cardiovascular diseases with the oxidation of the heme of soluble guanylyl cyclase (sgc) critically implicated in some of these cardiovascular diseases. sgc, the main nitric oxide (no) receptor, stimulates second messenger cgmp production, whereas reactive oxygen species are known to scavenge no and oxidize/inactivate t ...	2010	20463019
morphological and genetic diversity of symbiotic cyanobacteria from cycads.	the morphological and genetic diversity of cyanobacteria associated with cycads was examined using pcr amplification techniques and 16s rrna gene sequence analysis. eighteen symbiotic cyanobacteria were isolated from different cycad species. one of the symbiotic isolates was a species of calothrix, a genus not previously reported to form symbioses with cycadaceae family, and the remainder were nostoc spp. axenic cyanobacterial strains were compared by dna amplification using pcr with either shor ...	2010	20473963
treatment of cr(vi)-containing wastewaters with exopolysaccharide-producing cyanobacteria in pilot flow through and batch systems.	seven exopolysaccharide-producing cyanobacteria were tested with regard to their capability to remove cr(vi) from the wastewater of a plating industry. the cyanobacterium which showed, under lab conditions, the most promising features with regard to both cr(vi) removal (about 12 mg of cr(vi) removed per gram of dry biomass) and growth characteristics (highest growth rate and simplest culture medium) was nostoc pcc7936. furthermore, in lab experiments, it was also found that a hcl pretreatment is ...	2010	20508931
the cyabrb transcription factor cala regulates the iron superoxide dismutase in nostoc sp. strain pcc 7120.	in the present investigation the results of induced over-production of the cyabrb transcription factor cala (cyanobacterial abrb-like, annotated as alr0946) in the cyanobacterium nostoc sp. pcc 7120 were analysed. the cala overexpression strain showed a bleaching phenotype with lower growth rate and truncated filaments 2 days after induction of overexpression. the phenotype was even more pronounced when illumination was increased from 35 to 125 µmol m(-2) s(-1). using gel-based quantitative prot ...	2010	20545738
multiple origins of high reciprocal symbiotic specificity at an intercontinental spatial scale among gelatinous lichens (collemataceae, lecanoromycetes).	because the number of fungal species (mycobionts) exceeds the number of algae and cyanobacteria (photobionts) found in lichens by more than two orders of magnitude, reciprocal one-to-one specificity between one fungal species and one photobiont across their entire distribution is not expected in this symbiotic system, and has not previously been observed. the specificity of the cyanobacterium nostoc found in lichens was evaluated at a broad geographical scale within one of the main families of l ...	2010	20493269
structural features of the nostoc punctiforme debranching enzyme reveal the basis of its mechanism and substrate specificity.	the debranching enzyme nostoc punctiforme debranching enzyme (npde) from the cyanobacterium nostoc punctiforme (pcc73102) hydrolyzes the alpha-1,6 glycosidic linkages of malto-oligosaccharides. despite its high homology to cyclodextrin/pullulan (cd/pul)-hydrolyzing enzymes from glycosyl hydrolase 13 family (gh-13), npde exhibits a unique catalytic preference for longer malto-oligosaccharides (>g8), performing hydrolysis without the transgylcosylation or cd-hydrolyzing activities of other gh-13 e ...	2010	19768689
a novel cyanobacterial nostocyclopeptide is a potent antitoxin against microcystins.	cyanobacterial hepatotoxins (microcystins and nodularins) cause numerous animal poisonings worldwide each year and are threats to human health. however, we found that extracts from several cyanobacteria isolates failed to induce hepatotoxicity even if they contained high concentrations of the liver toxin microcystin. the antitoxic activity abolishes all morphological hallmarks of microcystin-induced apoptosis, and therefore invalidates cell-based assays of the microcystin content of bloom-formin ...	2010	20575133
the cell recognition model in chlorolichens involving a fungal lectin binding to an algal ligand can be extended to cyanolichens.	leptogium corniculatum, a cyanolichen containing nostoc as photobiont, produces and secretes arginase to culture medium containing arginine. this secreted arginase was pre-purified by affinity chromatography on beads of activated agarose to which a polygalactosylated urease, purified from evernia prunastri, was attached. arginase was eluted from the beads with 50 mm alpha-d-galactose. the eluted arginase binds preferentially to the cell surface of nostoc isolated from this lichen thallus, althou ...	2010	20636904
effect of psts sub-units or pknd deficiency on the survival of mycobacterium tuberculosis.	the membrane-associated phosphate-specific transporter (pst) complex is composed of four different proteins: psts, pstc, psta and pstb. the psts component detects and binds pi with high affinity; the psta and pstc form transmembrane pores for pi entry, while pstb provides energy through atp hydrolysis. in the mycobacterium tuberculosis genome, four different gene clusters encode three psts, and two of each of the other sub-units. we used rt-pcr to show that these clusters represent at least thre ...	2010	20933472
differential roles of alkaline/neutral invertases in nostoc sp. pcc 7120: inv-b isoform is essential for diazotrophic growth.	the presence of two alkaline/neutral invertases (inv-a and inv-b) in the filaments of nostoc (also named anabaena) sp. strain pcc 7120 and the involvement of sucrose metabolism in nitrogen fixation led us to investigate the physiological function of those isoforms in cells growing under different nitrogen sources. the highest expression level of each encoding gene was obtained in the presence of ammonium. these results were paralleled by polypeptide and enzyme activity level. in cells of n(2)-fi ...	2010	20938678
protein immobilization on liposomes and lipid-coated nanoparticles by protein trans-splicing.	a plethora of methods exist to link proteins to surfaces in order to generate functionalized materials. however, general tools that lead to functional immobilization of recombinantly expressed proteins on membranes such as liposomes or lipid-coated nanoparticles are rare. here we present an approach that takes advantage of a double-palmitoylated peptide that mediates stable membrane anchoring in combination with protein trans-splicing for efficient immobilization of recombinant proteins fused to ...	2010	20862726
color measurements as a reliable method for estimating chlorophyll degradation to phaeopigments.	the application of biocides is a traditional method of controlling biodecay of outdoor cultural heritage. chlorophyll degradation to phaeopigments is used to test the biocidal efficacy of the antimicrobial agents. in the present study, the usefulness of color measurements in estimating chlorophyll degradation was investigated. an aeroterrestrial stone biofilm-forming cyanobacterium of the genus nostoc was chosen as test organism, comparing its different behaviour in both planktonic and biofilm m ...	2010	20714920
variability in the response of the cyanobacterium nodularia spumigena to nitrogen supplementation.	nodularia spumigena is a filamentous cyanobacterium that is commonly found in brackish water bodies. the species is capable of fixing atmospheric nitrogen in specialized cells termed heterocysts. n. spumigena dominates the annual toxic summer blooms in the baltic sea causing environmental and economical problems. we have previously demonstrated that n. spumigena strain av1 exhibits a different response to the presence of combined nitrogen as compared to model cyanobacteria such as nostoc pcc7120 ...	2010	20820471
cylindrocyclophanes with proteasome inhibitory activity from the cyanobacterium nostoc sp.	material collected from a parkway in the city of chicago afforded the isolation of a nostoc species (uic 10022a). the extract of this strain displayed significant inhibition of the 20s proteasome as well as antiproliferative activity against ht29, mcf7, nci-h460, and sf268 cancer cell lines. a standardized dereplication protocol allowed for the rapid identification of three known (11-13) and nine new (1-9) chlorinated cylindrocyclophanes from less than 100 mg of organic extract. scale-up isolati ...	2010	20825206
microvirin, a novel alpha(1,2)-mannose-specific lectin isolated from microcystis aeruginosa, has anti-hiv-1 activity comparable with that of cyanovirin-n but a much higher safety profile.	microvirin (mvn), a recently isolated lectin from the cyanobacterium microcystis aeruginosa pcc7806, shares 33% identity with the potent anti-human immunodeficiency virus (hiv) protein cyanovirin-n (cv-n) isolated from nostoc ellipsosporum, and both lectins bind to similar carbohydrate structures. mvn is able to inhibit infection by a wide variety of hiv-1 laboratory-adapted strains and clinical isolates of different tropisms and subtypes in peripheral blood mononuclear cells. mvn also inhibits ...	2010	20507987
functional characterization of a naturally occurring trans-splicing intein from synechococcus elongatus in a mammalian cell system.	we have cloned and characterized a naturally occurring split mini-dnae intein capable of protein trans-splicing in the cyanobacterium synechococcus elongatus (sel dnae intein). sel dnae intein is homologous to synechocystissp. pcc6803 (ssp) dnae intein and nostoc punctiforme (npu) dnae intein, with a protein sequence identity of 60% for the n-terminal part of intein and 61% for the c-terminal part of intein. our results demonstrate that the split reporters, split renilla luciferase (rluc) and en ...	2010	20727340
multiple roles of soluble sugars in the establishment of gunnera-nostoc endosymbiosis.	gunnera plants have the unique ability to form endosymbioses with n(2)-fixing cyanobacteria, primarily nostoc. cyanobacteria enter gunnera through transiently active mucilage-secreting glands on stems. we took advantage of the nitrogen (n)-limitation-induced gland development in gunnera manicata to identify factors that may enable plant tissue to attract and maintain cyanobacteria colonies. cortical cells in stems of n-stressed gunnera plants were found to accumulate a copious amount of starch, ...	2010	20833727
assessment of salinity-induced antioxidative defense system of diazotrophic cyanobacterium nostoc muscorum.	the present study examines the salinity-induced oxidative damage and differential response of enzymatic and non-enzymatic antioxidants of nostoc muscorum. as compared to carotenoid content which showed induction the chlorophyll and phycocyanin contents were inhibited after salt stress. acceleration of lipid peroxidation and peroxide production suggested onset of oxidative damage. the activities of all studied enzymatic antioxidants were significantly increased by salt stress with maximum inducti ...	2010	21124054
exposure of the cyanobacterium nostoc muscorum from portuguese rice fields to molinate (ordram(®)): effects on the antioxidant system and fatty acid profile.	herbicide contamination of aquatic ecosystems is a serious global environmental concern. several herbicides enhance the intracellular formation of reactive oxygen species, and can lead to the damage of macromolecules and to a decrease of oxidant defenses in a wide range of non-target microorganisms including cyanobacteria. the effects of molinate (a thiocarbamate herbicide used for controlling grassy weeds in rice fields) on the activities of antioxidant enzymes such as superoxide dismutase, cat ...	2010	21216347
biological dinitrogen fixation by selected soil cyanobacteria as affected by strain origin, morphotype, and light conditions.	the potential for n(2) fixation by heterocystous cyanobacteria isolated from soils of different geographical areas was determined as nitrogenase activity (na) using the acetylene reduction assay. morphology of cyanobacteria had the largest influence on na determined under light conditions. na was generally higher in species lacking thick slime sheaths. the highest value (1446 nmol/h c(2)h(4) per g fresh biomass) was found in the strain of branched cyanobacterium hassalia (a has1) from the polar ...	2010	20941582
poly-β-hydroxybutyrate accumulation in cyanobacteria under photoautotrophy.	poly-β-hydroxybutyrate (phb) is a biodegradable and biocompatible polymer that has immense potential in the field of environmental, agricultural and biomedical sciences. an alternative host system has been explored in this study for low-cost production. examination of 25 cyanobacterial species from 19 different genera for photoautrophic production of polyhydroxyalkanoates (phas) under batch culture demonstrated that 20 species were poly-β-hydroxybutyrate (phb) accumulators, while others were fou ...	2010	20949541
raman spectroscopic analysis of a desert cyanobacterium nostoc sp. in response to uvb radiation.	cyanobacteria are capable of tolerating environmental extremes. to survive in extreme environments, cyanobacteria have developed the capability to adapt to a variety of stresses. for example, cyanobacteria have adopted a number of strategies with which to survive uv stress, including expression of uv-screening pigments and antioxidant systems. we have previously shown that several antioxidants are significantly expressed in nostoc sp. by uvb irradiation. we report here that the content of uv-res ...	2010	21087158
anabaena sp. strain pcc 7120 conr contains a lytr-cpsa-psr domain, is developmentally regulated, and is essential for diazotrophic growth and heterocyst morphogenesis.	the conr (all0187) gene of the filamentous cyanobacterium anabaena (nostoc) sp. strain pcc 7120 is predicted to be part of a family of proteins that contain the lytr-cpsa-psr domain associated with septum formation and cell wall maintenance. the conr gene was originally misannotated as a transcription regulator. northern rna blot analysis showed that conr expression was upregulated 8 h after nitrogen step-down. fluorescence microscopy of a p(conr)-gfp reporter strain revealed increased gfp fluor ...	2010	21088107
hydrogen production and metal-dye bioremoval by a nostoc linckia strain isolated from textile mill oxidation pond.	biohydrogen production by nostoc linckia ha-46, isolated from a textile-industry oxidation-pond was studied by varying light/dark period, ph, temperature and ratio of carbon-dioxide and argon in the gas-mixture. hydrogen production rates were maximum under 18 h of light and 6 h of darkness, ph 8.0, 31°c, a co(2):ar ratio 2:10. hydrogen production of the strain acclimatized to 20 mg/l of chromium/cobalt and 100 mg/l of reactive red 198/crystal violet dye studied in n-supplemented/deficient medium ...	2010	21109423
antiprotozoal, antitubercular and cytotoxic potential of cyanobacterial (blue-green algal) extracts from ireland.	cyanobacteria (= blue-green algae) are prolific producers of structurally distinct and biologically active metabolites. in the continuation of our search for new sources of anti-infective natural products, we have assessed the in vitro antiprotozoal (plasmodium falciparum, trypanosoma brucei rhodesiense, t. cruzi, leishmania donovani) and antitubercular (mycobacterium tuberculosis) potential of samples of two terrestrial cyanobacteria, nostoc commune (collected when desiccated and wet) and rivul ...	2011	21615033
nostocyclopeptide-m1: a potent, nontoxic inhibitor of the hepatocyte drug transporters oatp1b3 and oatp1b1.	we have isolated a novel cyanobacterial cyclic peptide (nostocyclopeptide m1; ncp-m1) that blocks the hepatotoxic action of microcystin (mc) and nodularin (nod). we show here that ncp-m1 is nontoxic to primary hepatocytes in long-term culture. ncp-m1 does not affect any known intracellular targets or pathways involved in mc action, like protein phosphatases, cam-kii, or ros-dependent cell death effectors. in support of this conclusion ncp-m1 had no protective effect when microinjected into cells ...	2011	21214185
purification and crystallization of the cyanobacterial cytochrome b6f complex.	the cytochrome b6f complex from the filamentous cyanobacteria (mastigocladus laminosus, nostoc sp. pcc 7120) and spinach chloroplasts has been purified as a homo-dimer. electrospray ionization mass spectroscopy showed the monomer to contain eight and nine subunits, respectively, and dimeric masses of 217.1, 214.2, and 286.5 kda for m. laminosus, nostoc, and the complex from spinach. the core subunits containing or interacting with redox-active prosthetic groups are peta (cytochrome f), b (cytoch ...	2011	20960122
purification of plastocyanin and cytochrome c6 from plants, green algae, and cyanobacteria.	plastocyanin and cytochrome c6 are widely distributed over the oxygen-evolving photosynthetic organisms. the two proteins are functionally equivalent, but strongly differ in their global electrostatic charge. in fact, they are acidic in eukaryotes, but either neutral or basic in cyanobacteria. such a difference in their electrostatic features is a critical factor in designing the purification procedure, which must thus be modified and adapted accordingly. this chapter reports the methods for pro ...	2011	20960123
effect of crowding on the electron transfer process from plastocyanin and cytochrome c6 to photosystem i: a comparative study from cyanobacteria to green algae.	plastocyanin and cytochrome c(6), the alternate donor proteins to photosystem i, can be acidic, neutral or basic; the role of electrostatics in their interaction with photosystem i vary accordingly for cyanobacteria, algae and plants. the effect of different crowding agents on the kinetics of the reaction between plastocyanin or cytochrome c(6) and photosystem i from three different cyanobacteria, synechocystis pcc 6803, nostoc pcc 7119 and arthrospira maxima, and a green alga, monoraphidium bra ...	2011	21344311
kinetic control of one-pot trans-splicing reactions by using a wild-type and designed split intein.		2011	21656885
novel glycosylated mycosporine-like amino acids with radical scavenging activity from the cyanobacterium nostoc commune.	mycosporine-like amino acids (maas) are uv absorbing pigments, and structurally distinct maas have been identified in taxonomically diverse organisms. two novel maas were purified from the cyanobacterium nostoc commune, and their chemical structures were characterized. an maa with an absorption maximum at 335nm was identified as a pentose-bound porphyra-334 derivative with a molecular mass of 478da. another identified maa had double absorption maxima at 312 and 340nm and a molecular mass of 1050 ...	2011	21813286
differential physiological and biochemical responses of two cyanobacteria nostoc muscorum and phormidium foveolarum against oxyfluorfen and uv-b radiation.	in the present study, degree of tolerance and tolerance strategies of two paddy field cyanobacteria viz. nostoc muscorum and phormidium foveolarum against oxyfluorfen (10 and 20µgml(-1)) and uv-b (7.2kjm(-2)d(-1)) stress were investigated. oxyfluorfen and uv-b decreased growth, photosynthesis, nutrient uptake, nitrate reductase, acid and alkaline phosphatase activities, which accompanied with the increase in the level of oxidative stress. however, growth was more affected in n. muscorum than p. ...	2011	21798597
diversity analysis of type i ketosynthase in rhizosphere soil of cucumber.	fusarium wilt [fusarium oxysporum (sch1.) f.sp. cucumerinum owen.] is a major soil-borne disease of cucumber worldwide, and can cause huge yield losses. biological control of fusarium wilt of cucumber has received considerable attention. many bacteria, particularly actinomycetes, are known to produce secondary metabolites synthesized by polyketide synthases (pkss) with a diverse range of biological activities. ketosynthase (ks) gene diversity was analyzed in samples which were collected from rhi ...	2011	21780139
evaluation and comparison of protein splicing by exogenous inteins with foreign exteins in escherichia coli.	protein splicing catalyzed by inteins has enabled various biotechnological applications such as protein ligation. successful applications of inteins are often limited by splicing efficiency. here, we report the comparison of protein splicing between 20 different inteins from various organisms in identical contexts to identify robust inteins with foreign exteins. we found that rada intein from pyrococcus horikoshii and an engineered dnab intein from nostoc punctiforme demonstrated an equally effi ...	2011	22001202
development of a novel dnae intein-based assay for quantitative analysis of g-protein-coupled receptor internalization.	g-protein-coupled receptor (gpcr) internalization provides a g-protein-subtype-independent method for assaying agonist-stimulated activation of receptors. we have developed a novel assay that allows quantitative analysis of gpcr internalization based on the interaction between activated gpcrs and +¦-arrestin2 and on nostoc punctiforme dnae intein-mediated reconstitution of renilla luciferase fragments. this assay system was validated using four functionally divergent gpcrs treated with agonists ...	2011	21726524
diverse two-cysteine photocycles in phytochromes and cyanobacteriochromes.	phytochromes are well-known as photoactive red- and near ir-absorbing chromoproteins with cysteine-linked linear tetrapyrrole (bilin) prosthetic groups. phytochrome photoswitching regulates adaptive responses to light in both photosynthetic and nonphotosynthetic organisms. exclusively found in cyanobacteria, the related cyanobacteriochrome (cbcr) sensors extend the photosensory range of the phytochrome superfamily to shorter wavelengths of visible light. blue/green light sensing by a well-studie ...	2011	21712441
directional rna deep sequencing sheds new light on the transcriptional response of anabaena sp. strain pcc 7120 to combined-nitrogen deprivation.	cyanobacteria are potential sources of renewable chemicals and biofuels and serve as model organisms for bacterial photosynthesis, nitrogen fixation, and responses to environmental changes. anabaena (nostoc) sp. strain pcc 7120 (hereafter anabaena) is a multicellular filamentous cyanobacterium that can "fix" atmospheric nitrogen into ammonia when grown in the absence of a source of combined nitrogen. because the nitrogenase enzyme is oxygen sensitive, anabaena forms specialized cells called hete ...	2011	21711558
Antagonistic interactions between filamentous heterotrophs and the cyanobacterium Nostoc muscorum.	ABSTRACT:	2011	21914201
integrating photobiological hydrogen production with dye-metal bioremoval from simulated textile wastewater.	the study reports production of hydrogen in photobioreactors with free (pbr(fr)) and immobilized (pbr(imm)) nostoc biomass at enhanced and sustained rates. before running the photobioreactors, effects of different immobilization matrices and cyanobacterial dose on hydrogen production were studied in batch mode. as hydrogen production in the pbrs declined spent biomass from the photobioreactors were collected and utilized further for column biosorption of highly toxic dyes (reactive red 198+cryst ...	2011	21890340
oxygen-independent alkane formation by non-heme iron-dependent cyanobacterial aldehyde decarbonylase: investigation of kinetics and requirement for an external electron donor.	cyanobacterial aldehyde decarbonylase (cad) is, structurally, a member of the di-iron carboxylate family of oxygenases. we previously reported that cad from prochlorococcus marinus catalyzes the unusual hydrolysis of aldehydes to produce alkanes and formate in a reaction that requires an external reducing system but does not require oxygen [das et al. (2011) angew. chem. 50, 7148-7152]. here we demonstrate that cads from divergent cyanobacterial classes, including the enzyme from n. puntiformes ...	2011	22074177
femtosecond photodynamics of the red/green cyanobacteriochrome npr6012g4 from nostoc punctiforme. 1. forward dynamics.	phytochromes are well-known red/far-red photosensory proteins that utilize the photoisomerization of a linear tetrapyrrole (bilin) chromophore to detect the ratio of red to far-red light. cyanobacteriochromes (cbcrs) are related photosensory proteins with a bilin-binding gaf domain, but much more diverse spectral sensitivity, with five recognized subfamilies of cbcrs described to date. the mechanisms that underlie this spectral diversity have not yet been fully elucidated. one of the main cbcr s ...	2011	22148715
post-storage potential of nostoc linckia (cyanobacteria) immobilized in ca-alginate (synthetic seed) as biofertilizer inocula.		2011	21914973