| reassembly of shattered chromosomes in deinococcus radiodurans. | dehydration or desiccation is one of the most frequent and severe challenges to living cells. the bacterium deinococcus radiodurans is the best known extremophile among the few organisms that can survive extremely high exposures to desiccation and ionizing radiation, which shatter its genome into hundreds of short dna fragments. remarkably, these fragments are readily reassembled into a functional 3.28-megabase genome. here we describe the relevant two-stage dna repair process, which involves a ... | 2006 | 17006450 |
| physiological changes induced in four bacterial strains following oxidative stress. | in order to study the behaviour and resistance of bacteria under extreme conditions, physiological changes associated with oxidative stress were monitored using flow cytometry. the study was conducted to assess the maintenance of membrane integrity and potential as well as the esterase activity, the intracellular ph and the production of superoxide anions in four bacterial strains (ralstonia metallidurans, escherichia coli, shewanella oneidensis and deinococcus radiodurans). the strains were cho ... | 2006 | 17022450 |
| microbiology: resurrecting a broken genome. | | 2006 | 17024079 |
| phylogenetic diversity and activity of aerobic heterotrophic bacteria from a hypersaline oil-polluted microbial mat. | the diversity and function of aerobic heterotrophic bacteria (ahb) in cyanobacterial mats have been largely overlooked. we used culture-dependent and molecular techniques to explore the species diversity, degradative capacities and functional guilds of ahb in the photic layer (2mm) of an oil-polluted microbial mat from saudi arabia. enrichment isolation was carried out at different salinities (5% and 12%) and temperatures (28 and 45 degrees c) and on various substrates (acetate, glycolate, spiru ... | 2007 | 17056222 |
| engineering of deinococcus radiodurans r1 for bioprecipitation of uranium from dilute nuclear waste. | genetic engineering of radiation-resistant organisms to recover radionuclides/heavy metals from radioactive wastes is an attractive proposition. we have constructed a deinococcus radiodurans strain harboring phon, a gene encoding a nonspecific acid phosphatase, obtained from a local isolate of salmonella enterica serovar typhi. the recombinant strain expressed an approximately 27-kda active phon protein and efficiently precipitated over 90% of the uranium from a 0.8 mm uranyl nitrate solution in ... | 2006 | 17056698 |
| molecular analyses of microbial diversity associated with the lonar soda lake in india: an impact crater in a basalt area. | the prokaryotic diversity associated with an indian soda lake (lonar crater lake) located in a basaltic soil area was investigated using a culture-independent approach. community dna was extracted directly from four sediment samples obtained by coring to depths of 10-20 cm. small subunit rrna genes (16s rdna) were amplified by pcr using primers specific to the domains bacteria and archaea. the pcr products were cloned and sequenced. for the bacterial rdna clone library, 500 clones were randomly ... | 2006 | 17070674 |
| down-regulation of radioresistance by lexa2 in deinococcus radiodurans. | the extremely radioresistant bacterium deinococcus radiodurans contains two lexa homologues (lexa1 and lexa2) that are possible transcriptional regulators associated with the dna damage response. in this study, resequencing revealed that there was an additional cytosine nucleotide (nucleotide position 612) in the d. radiodurans lexa2 gene. purified lexa2 possessed proteolytic activity that could be stimulated by reca. in an effort to gain an insight into the role of lexa2 in the radiation respon ... | 2006 | 17074893 |
| analysis of double stranded dna-dependent activities of deinococcus radiodurans reca protein. | in this study, the double-stranded dna-dependent activities of deinococcus radiodurans reca protein (dr reca) were characterized. the interactions of the dr reca protein with double-stranded dna were determined, especially dsdna-dependent atp hydrolysis by the dr reca protein and the dna strand exchange reaction, in which multiple branch points exist on a single reca protein-dna complex. a nucleotide cofactor (atp or datp ) was required for the dr reca protein binding to duplex dna. in the prese ... | 2006 | 17082744 |
| three tandem hrdc domains have synergistic effect on the recq functions in deinococcus radiodurans. | the recq family of dna helicases performs essential functions in the maintenance of genomic stability in all organisms. in deinococcus radiodurans, dr1289 is a special member of recq family with unique arrangement of three tandem hrdc domains in the c-terminus. a dr1289 mutant is hypersensitive to gamma-irradiation, uv, h2o2 and mitomycin c. by complementing the dr1289 mutant with various domains of dr1289 in vivo, we have determined that the helicase and all three hrdc domains are indispensable ... | 2007 | 17085080 |
| [deinococcus radiodurans, "if you want to destroy your life"]. | | 2006 | 17101106 |
| substrate specificity analysis and inhibitor design of homoisocitrate dehydrogenase. | homoisocitrate dehydrogenase is involved in the alpha-aminoadipate pathway of biosynthesis of l-lysine in fungi, yeast, some prokaryotic bacteria, and archaea. this enzyme catalyzes the oxidative decarboxylation of (2r,3s)-homoisocitrate into 2-oxoadipate using nad(+) as a coenzyme. substrate specificity of two homoisocitrate dehydrogenases derived from deinococcus radiodurans and saccharomyces cerevisiae was analyzed using a series of synthetic substrate analogs, which indicated a relatively br ... | 2007 | 17116397 |
| bacterial flavodoxins support nitric oxide production by bacillus subtilis nitric-oxide synthase. | unlike animal nitric-oxide synthases (noss), the bacterial nos enzymes have no attached flavoprotein domain to reduce their heme and so must rely on unknown bacterial proteins for electrons. we tested the ability of two bacillus subtilis flavodoxins (ykun and ykup) to support catalysis by purified b. subtilis nos (bsnos). when an nadph-utilizing bacterial flavodoxin reductase (fldr) was added to reduce ykup or ykun, both supported no synthesis from either l-arginine or n-hydroxyarginine and supp ... | 2007 | 17127770 |
| polar destabilization of dna duplexes with single-stranded overhangs by the deinococcus radiodurans ssb protein. | the deinococcus radiodurans ssb protein has an occluded site size of 50 +/- 2 nucleotides on ssdna but can form a stable complex with a 26-30-nucleotide oligodeoxynucleotide using a subset of its four ssdna binding domains. quantitative estimates of d. radiodurans ssb protein in the d. radiodurans cell indicate approximately 2500-3000 dimers/cell, independent of the level of irradiation. at biologically relevant concentrations, when bound at single-strand-double-strand dna junctions in vitro, d. ... | 2006 | 17128988 |
| characterization of a bifunctional aminoacylase/carboxypeptidase from radioresistant bacterium deinococcus radiodurans r1. | the gene encoding a deinococcus radiodurans r1 bifunctional aminoacylase/carboxypeptidase (dr_acy/cp) was amplified by polymerase chain reaction and cloned into pqe-30 to generate pqe-drac. the cloned gene consists of an open reading frame of 1197 bp encoding a protein with a molecular mass of 42,729 da. the predicted amino acid sequence shows high homology with those of geobacillus kaustophilus aminoacylase, geobacillus stearothermophilus aminoacylase, pyrococcus horikoshii carboxypeptidase/ami ... | 2007 | 17129628 |
| crystal structure of 1-deoxy-d-xylulose 5-phosphate synthase, a crucial enzyme for isoprenoids biosynthesis. | isopentenyl pyrophosphate (ipp) is a common precursor for the synthesis of all isoprenoids, which have important functions in living organisms. ipp is produced by the mevalonate pathway in archaea, fungi, and animals. in contrast, ipp is synthesized by a mevalonate-independent pathway in most bacteria, algae, and plant plastids. 1-deoxy-d-xylulose 5-phosphate synthase (dxs) catalyzes the first and the rate-limiting step of the mevalonate-independent pathway and is an attractive target for the de ... | 2007 | 17135236 |
| microbial community of a hydrothermal mud vent underneath the deep-sea anoxic brine lake urania (eastern mediterranean). | the composition of a metabolically active prokaryotic community thriving in hydrothermal mud fluids of the deep-sea hypersaline anoxic western urania basin was characterized using rrna-based phylogenetic analysis of a clone library. the physiologically active prokaryotic assemblage in this extreme environment showed a great genetic diversity. most members of the microbial community appeared to be affiliated to yet uncultured organisms from similar ecosystems, i.e., deep-sea hypersaline basins an ... | 2007 | 17136435 |
| enantioselective synthesis of l-homophenylalanine by whole cells of recombinant escherichia coli expressing l-aminoacylase and n-acylamino acid racemase genes from deinococcus radiodurans bcrc12827. | l-homophenylalanine (l-hpa) is a chiral unnatural amino acid used in the synthesis of angiotensin converting enzyme inhibitors and many pharmaceuticals. to develop a bioconversion process with dynamic resolution of n-acylamino acids for the l-hpa production, n-acylamino acid racemase (naaar) and l-aminoacylase (laa) genes were cloned from deinococcus radiodurans bcrc12827 and expressed in escherichia coli xliblue. the recombinant enzymes were purified by nickel-chelate chromatography, and their ... | 2006 | 17137304 |
| identification, cloning, expression, and characterization of a highly thermostable single-stranded-dna-binding protein (ssb) from deinococcus murrayi. | we report identification and characterization of ssb-like protein from deinococcus murrayi (dmussb). pcr-derived dna fragment containing the complete structural gene for dmussb was cloned and expressed in escherichia coli. the gene consisted of an open reading frame of 826 nucleotides encoding a protein of 276 amino acid residues with a calculated molecular weight of 30.14 kda. dmussb includes two ob folds per monomer and functions as a homodimer. in fluorescence titrations with poly(dt) dmussb ... | 2007 | 17175167 |
| multiple-stress tolerance of ionizing radiation-resistant bacterial isolates obtained from various habitats: correlation between stresses. | isolation of five ionizing radiation (ir)-resistant bacteria by screening of isolates from various habitats classified as common and stressed is reported. ir-resistant isolates exhibited varying degrees of resistance to gamma-radiation and were classified as highly and moderately radiation resistant. resistance to ultraviolet (uv) radiation correlated well with gamma-radiation resistance, whereas a comparable desiccation resistance for all the highly and moderately radiation-resistant isolates w ... | 2007 | 17180747 |
| synthesis of cysteinyl-trnacys by a prolyl-trna synthetase. | the question of how cysteinyl-trna(cys) is synthesized in organisms that lack a canonical cysteinyl-trna synthetase (cysrs) is an important open question in understanding protein synthesis. the prolyl-trna synthetase (prors) of wide ranging organisms has the ability to mis-activate cysteine without editing. this raises the question of whether the mis-activated cysteine can be charged to trna(cys) to synthesize the correctly matched cys-trna(cys), which may serve as an option in organisms that la ... | 2004 | 17194940 |
| deinococcus radiodurans rna ligase exemplifies a novel ligase clade with a distinctive n-terminal module that is important for 5'-po4 nick sealing and ligase adenylylation but dispensable for phosphodiester formation at an adenylylated nick. | deinococcus radiodurans rna ligase (drarnl) is a template-directed ligase that seals nicked duplexes in which the 3'-oh strand is rna. drarnl is a 342 amino acid polypeptide composed of a c-terminal adenylyltransferase domain fused to a distinctive 126 amino acid n-terminal module (a putative ob-fold). an alanine scan of the c domain identified 9 amino acids essential for nick ligation, which are located within nucleotidyltransferase motifs i, ia, iii, iiia, iv and v. seven mutants were dysfunct ... | 2007 | 17204483 |
| radiation resistance: resurrection by recombination. | adaptation to extreme desiccation has conferred extraordinary radiation resistance on the bacterium deinococcus radiodurans. how this organism is able to reconstruct a genome shattered by gamma rays has now been revealed. | 2007 | 17208168 |
| mutagenesis and repair in bacillus anthracis: the effect of mutators. | we have generated mutator strains of bacillus anthracis sterne by using directed gene knockouts to investigate the effect of deleting genes involved in mismatch repair, oxidative repair, and maintaining triphosphate pools. the single-knockout strains are deleted for muts, muty, mutm, or ndk. we also made double-knockout strains that are muts ndk or muty mutm. we have measured the levels of mutations in the rpob gene that lead to the rif(r) phenotype and have examined the mutational specificity. ... | 2007 | 17220233 |
| detection of green fluorescent protein in a single bacterium by capillary electrophoresis with laser-induced fluorescence. | green fluorescence protein (gfp) is a common reporter used to monitor protein expression in single cells. however, autofluorescence from endogenous components can mask the signal from gfp, particularly at low expression levels in prokaryotes. we employ capillary electrophoresis with laser-induced fluorescence for the analysis of the expression of green fluorescent protein in a single bacterium. capillary electrophoresis separates gfp from native cellular autofluorescent components, reducing the ... | 2007 | 17222051 |
| hypolithic community shifts occur as a result of liquid water availability along environmental gradients in china's hot and cold hyperarid deserts. | hypolithic cyanobacterial communities occur in hot and cold hyperarid environments but the physical factors determining their diversity are not well understood. here we report hypolithic diversity and colonization of a common quartz substrate at several hyperarid locations in the ancient deserts of north-western china, that experience varying mean annual temperature, rainfall and concomitant availability of liquid water in soil. microscopy and enrichment culture resulted only in chroococcidiopsi ... | 2007 | 17222139 |
| structural conservation of recf and rad50: implications for dna recognition and recf function. | recf, together with reco and recr, belongs to a ubiquitous group of recombination mediators (rms) that includes eukaryotic proteins such as rad52 and brca2. rms help maintain genome stability in the presence of dna damage by loading reca-like recombinases and displacing single-stranded dna-binding proteins. here, we present the crystal structure of recf from deinococcus radiodurans. recf exhibits a high degree of structural similarity with the head domain of rad50, but lacks its long coiled-coil ... | 2007 | 17255941 |
| deinococcus yunweiensis sp. nov., a gamma- and uv-radiation-resistant bacterium from china. | a gram-negative, non-spore-forming, non-motile, rod-shaped, red-pigmented strain, designated yim 007t, was found as a contaminant on an agar plate in the laboratory of yunnan institute of microbiology, china. the optimum growth ph and temperature for the isolate were 7.0-7.5 and 30 degrees c, respectively. the predominant respiratory quinone was mk-8. the polar lipid profile consisted mainly of various unknown phosphoglycolipids and glycolipids. the major cellular fatty acids were c(16 : 1)omega ... | 2007 | 17267981 |
| deinococcus glutaminyl-trna synthetase is a chimer between proteins from an ancient and the modern pathways of aminoacyl-trna formation. | glutaminyl-trna synthetase from deinococcus radiodurans possesses a c-terminal extension of 215 residues appending the anticodon-binding domain. this domain constitutes a paralog of the yqey protein present in various organisms and part of it is present in the c-terminal end of the gatb subunit of gatcab, a partner of the indirect pathway of gln-trna(gln) formation. to analyze the peculiarities of the structure-function relationship of this glnrs related to the yqey domain, a structure of the pr ... | 2007 | 17284460 |
| widespread occurrence and genomic context of unusually small polyketide synthase genes in microbial consortia associated with marine sponges. | numerous marine sponges harbor enormous amounts of as-yet-uncultivated bacteria in their tissues. there is increasing evidence that these symbionts play an important role in the synthesis of protective metabolites, many of which are of great pharmacological interest. in this study, genes for the biosynthesis of polyketides, one of the most important classes of bioactive natural products, were systematically investigated in 20 demosponge species from different oceans. unexpectedly, the sponge met ... | 2007 | 17293531 |
| lesion bypass activity of dna polymerase a from the extremely radioresistant organism deinococcus radiodurans. | the bacterium deinococcus radiodurans survives extremely high exposure to ionizing radiation and extended periods of desiccation. radiation at the survival doses is known to cause numerous dna damage, such as hundreds of double strand breaks and single strand breaks, as well as damage of the nucleobases. the mechanisms of d. radiodurans to survive the depicted threats are still only beginning to be understood. dna polymerase a (pola) has been shown to be crucially involved in irradiation resista ... | 2007 | 17303573 |
| high resolution structure of deinococcus bacteriophytochrome yields new insights into phytochrome architecture and evolution. | phytochromes are red/far red light photochromic photoreceptors that direct many photosensory behaviors in the bacterial, fungal, and plant kingdoms. they consist of an n-terminal domain that covalently binds a bilin chromophore and a c-terminal region that transmits the light signal, often through a histidine kinase relay. using x-ray crystallography, we recently solved the first three-dimensional structure of a phytochrome, using the chromophore-binding domain of deinococcus radiodurans bacteri ... | 2007 | 17322301 |
| thin film processing using s-layer proteins: biotemplated assembly of colloidal gold etch masks for fabrication of silicon nanopillar arrays. | we explored the bionanofabrication of silicon nanopillar structures using ordered gold nanoparticle arrays generated from microbial surface layer (s-layer) protein templates. the s-layer template used for these thin film processing experiments was isolated from the gram-positive bacterium deinococcus radiodurans. in this preliminary work, s-layers preimmobilized onto chemically modified silicon substrates were initially used to template the fabrication of a nanolithographic hard mask pattern com ... | 2007 | 17324560 |
| identification and properties of the deinococcus grandis and deinococcus proteolyticus single-stranded dna binding proteins (ssb). | to study the biochemical properties of ssb's from deinococcus grandis (dgrssb) and deinococcus proteolyticus (dprssb), we have cloned the ssb genes obtained by pcr and have developed escherichia coli overexpression systems. the genes consist of an open reading frame of 891 (dgrssb) and 876 (dprssb) nucleotides encoding proteins of 296 and 291 amino acids with a calculated molecular mass of 32.29 and 31.33 kda, respectively. the amino-acid sequence of dgrssb exhibits 45%, 44% and 82% identity and ... | 2007 | 17325748 |
| the n-terminal extensions of deinococcus radiodurans dps-1 mediate dna major groove interactions as well as assembly of the dodecamer. | dps (dna protection during starvation) proteins play an important role in the protection of prokaryotic macromolecules from damage by reactive oxygen species. previous studies have suggested that the lysine-rich n-terminal tail of dps proteins participates in dna binding. in comparison with other dps proteins, dps-1 from deinococcus radiodurans has an extended n terminus comprising 55 amino acids preceding the first helix of the 4-helix bundle monomer. in the crystal structure of dps-1, the firs ... | 2007 | 17331944 |
| induced-fit tightens pleuromutilins binding to ribosomes and remote interactions enable their selectivity. | new insights into functional flexibility at the peptidyl transferase center (ptc) and its vicinity were obtained by analysis of pleuromutilins binding modes to the ribosome. the crystal structures of deinococcus radiodurans large ribosomal subunit complexed with each of three pleuromutilin derivatives: retapamulin (sb-275833), sb-280080, and sb-571519, show that all bind to the ptc with their core oriented similarly at the a-site and their c14 extensions pointing toward the p-site. except for an ... | 2007 | 17360517 |
| evaluation of the antioxidant effects of carotenoids from deinococcus radiodurans through targeted mutagenesis, chemiluminescence, and dna damage analyses. | deinococcus radiodurans is highly resistant to reactive oxygen species (ros). the antioxidant effect of carotenoids in d. radiodurans was investigated by using a targeted mutation of the phytoene synthase gene to block the carotenoid synthesis pathway and by evaluating the survival of cells under environmental stresses. the colorless mutant r1deltacrtb of d. radiodurans failed to synthesize carotenoids, and was more sensitive to ionizing radiation, hydrogen peroxide, and desiccation than the wil ... | 2007 | 17368731 |
| transcription activation mediated by a cyclic amp receptor protein from thermus thermophilus hb8. | the extremely thermophilic bacterium thermus thermophilus hb8, which belongs to the phylum deinococcus-thermus, has an open reading frame encoding a protein belonging to the cyclic amp (camp) receptor protein (crp) family present in many bacteria. the protein named t. thermophilus crp is highly homologous to the crp family proteins from the phyla firmicutes, actinobacteria, and cyanobacteria, and it forms a homodimer and interacts with camp. crp mrna and intracellular camp were detected in this ... | 2007 | 17369302 |
| protein oxidation implicated as the primary determinant of bacterial radioresistance. | in the hierarchy of cellular targets damaged by ionizing radiation (ir), classical models of radiation toxicity place dna at the top. yet, many prokaryotes are killed by doses of ir that cause little dna damage. here we have probed the nature of mn-facilitated ir resistance in deinococcus radiodurans, which together with other extremely ir-resistant bacteria have high intracellular mn/fe concentration ratios compared to ir-sensitive bacteria. for in vitro and in vivo irradiation, we demonstrate ... | 2007 | 17373858 |
| homologous expression of a bacterial phytochrome. the cyanobacterium fremyella diplosiphon incorporates biliverdin as a genuine, functional chromophore. | bacteriophytochromes constitute a light-sensing subgroup of sensory kinases with a chromophore-binding motif in the n-terminal half and a c-terminally located histidine kinase activity. the cyanobacterium fremyella diplosiphon (also designated calothrix sp.) expresses two sequentially very similar bacteriophytochromes, cyanobacterial phytochrome a (cpha) and cyanobacterial phytochrome b (cphb). cyanobacterial phytochrome a has the canonical cysteine residue, by which covalent chromophore attachm ... | 2007 | 17388813 |
| crystal structure of rsr, an ortholog of the antigenic ro protein, links conformational flexibility to rna binding activity. | ro ribonucleoproteins are a class of antigenic ribonucleoproteins associated with rheumatic autoimmune diseases like systemic lupus erythematosus and sjögrens syndrome in humans. ro ribonucleoproteins are mostly composed of the 60-kda ro protein and small cytoplasmic rnas, called y rnas, of unknown function. in eukaryotes, where ro has been found to associate with damaged or mutant rnas, it has been suggested that ro may play a role in rna quality control. in the radiation-resistant bacterium de ... | 2007 | 17392270 |
| role of the c-terminal domain of thermus thermophilus trehalose synthase in the thermophilicity, thermostability, and efficient production of trehalose. | trehalose synthase (ts) from thermus thermophilus (ttts) is a thermostable enzyme that catalyzes the conversion of maltose into trehalose by intramolecular transglucosylation. it has a relatively higher thermophilicity and thermostability and a better conversion ratio for trehalose production than other known tss from different sources at present. by amino acid sequences and the schematic motif alignment of trehalose synthase-related enzymes, it was found that ttts (965 amino acid residues) cont ... | 2007 | 17394343 |
| modeling the isoelectric focusing of peptides in an offgel multicompartment cell. | in proteomic analysis of complex samples at the peptide level (termed shotgun proteomics), an effective prefractionation is crucial to decrease the complexity of the peptide mixture for further analysis. in this perspective, the high-resolving power of the ief fractionation step is a determining parameter, in order to obtain well-defined fractions and correct information on peptide isoelectric points, to provide an additional filter for protein identification. here, we explore the resolving powe ... | 2007 | 17397209 |
| stability of s-layer proteins for electrochemical nanofabrication. | crystalline cell surface layer proteins (s-layers) can be used in electrochemical fabrication to create nanoscale arrays of metals and oxides on surfaces so long as the proteins maintain their long-range order during processing. we have explored the stability of the hpi layer protein (the s-layer protein from the microorganism deinococcus radiodurans) adsorbed onto platinum surfaces after immersion in sulfuric acid or sodium hydroxide electrolytes ranging in ph from 0 to 14 over time periods ran ... | 2007 | 17399961 |
| comparative genomics of small rnas in bacterial genomes. | in recent years, various families of small non-coding rnas (srnas) have been discovered by experimental and computational approaches, both in bacterial and eukaryotic genomes. although most of them await elucidation of their function, it has been reported that some play important roles in gene regulation. here we carried out comparative genomics analysis of possible srnas that are computationally identified in 30 bacterial genomes from gamma- and alpha-proteobacteria and deinococcus radiodurans. ... | 2007 | 17411396 |
| a new role of deinococcus radiodurans recd in antioxidant pathway. | in deinococcus radiodurans, recbcd holoenzyme is not intact because of the absence of recb and recc, but a recd-like protein does indeed exist. in this work, d. radiodurans recd disruptant was constructed and its possible biological functions were investigated. the results showed that disruption of the recd gene of d. radiodurans resulted in a remarkably increased sensitivity to hydrogen peroxide but had no apparent effect on the resistance to gamma and uv radiation. furthermore, complementation ... | 2007 | 17419762 |
| phylogenetic and disruption analyses of aspartate kinase of deinococcus radiodurans. | the extremely radioresistant bacterium deinococcus radiodurans is evolutionarily closely related to the extremely thermophilic bacterium thermus thermophilus. these bacteria have a single gene encoding an aspartate kinase (ak) that catalyzes the phosphorylation of l-aspartate. t. thermophilus has an aminoadipate pathway for lysine biosynthesis that does not use ak for lysine biosynthesis. phylogenetic analysis in this study indicated that d. radiodurans ak has a different protein structure and a ... | 2007 | 17420586 |
| the crystal structure of dr2241 from deinococcus radiodurans at 1.9 a resolution reveals a multi-domain protein with structural similarity to chelatases but also with two additional novel domains. | a unique family of proteins have been identified in the deinococcus genus with an n-terminal cobalamin (vitamin b(12)) chelatase domain denoted cbix and an additional unique c-terminal domain with unknown function. here we report the first crystal structure from this new family of proteins with the structure of deinococcus radiodurans protein dr2241. the structure reveals a multi-domain protein where domains a (residues 1-132) has the same fold as the small cbix (cbix(s)), domains a and b (resid ... | 2007 | 17448684 |
| estimation of phylogeny and invariant sites under the general markov model of nucleotide sequence evolution. | the models of nucleotide substitution used by most maximum likelihood-based methods assume that the evolutionary process is stationary, reversible, and homogeneous. we present an extension of the barry and hartigan model, which can be used to estimate parameters by maximum likelihood (ml) when the data contain invariant sites and there are violations of the assumptions of stationarity, reversibility, and homogeneity. unlike most ml methods for estimating invariant sites, we estimate the nucleoti ... | 2007 | 17454972 |
| identification and functional analysis of a phytoene desaturase gene from the extremely radioresistant bacterium deinococcus radiodurans. | the phytoene-related desaturases are the key enzymes in the carotenoid biosynthetic pathway. the gene encoding phytoene desaturase in the deinoxanthin synthesis pathway of deinococcus radiodurans was identified and characterized. two putative phytoene desaturase homologues (dr0861 and dr0810) were identified by analysis of conserved amino acid regions, and the former displayed the highest identity (68 %) with phytoene desaturase of the cyanobacterium gloeobacter violaceus. dr0861 gene knockout a ... | 2007 | 17464079 |
| additive effects of sbccd and polx deficiencies in the in vivo repair of dna double-strand breaks in deinococcus radiodurans. | orthologs of proteins sbcd (mre11) and sbcc (rad50) exist in all kingdoms of life and are involved in a wide variety of dna repair and maintenance functions, including homologous recombination and nonhomologous end joining. here, we have inactivated the sbcc and/or sbcd genes of deinococcus radiodurans, a highly radioresistant bacterium able to mend hundreds of radiation-induced dna double-strand breaks (dsb). mutants devoid of the sbcc and/or sbcd proteins displayed reduced survival and present ... | 2007 | 17483232 |
| effect of a recd mutation on dna damage resistance and transformation in deinococcus radiodurans. | the bacterium deinococcus radiodurans is resistant to extremely high levels of dna-damaging agents such as uv light, ionizing radiation, and chemicals such as hydrogen peroxide and mitomycin c. the organism is able to repair large numbers of double-strand breaks caused by ionizing radiation, in spite of the lack of the recbcd enzyme, which is essential for double-strand dna break repair in escherichia coli and many other bacteria. the d. radiodurans genome sequence indicates that the organism la ... | 2007 | 17496087 |
| an ortholog of the ro autoantigen functions in 23s rrna maturation in d. radiodurans. | in both animal cells and the eubacterium deinococcus radiodurans, the ro autoantigen, a ring-shaped rna-binding protein, associates with small rnas called y rnas. in vertebrates, ro also binds the 3' ends of misfolded rnas and is proposed to function in quality control. however, little is known about the function of ro and the y rnas in vivo. here, we report that the d. radiodurans ortholog rsr (ro sixty related) functions with exoribonucleases in 23s rrna maturation. during normal growth, 23s r ... | 2007 | 17510283 |
| specific recognition of the -10 promoter element by the free rna polymerase sigma subunit. | bacterial rna polymerase holoenzyme relies on its sigma subunit for promoter recognition and opening. in the holoenzyme, regions 2 and 4 of the sigma subunit are positioned at an optimal distance to allow specific recognition of the -10 and -35 promoter elements, respectively. in free sigma, the promoter binding regions are positioned closer to each other and are masked for interactions with the promoter, with sigma region 1 playing a role in the masking. to analyze the dna-binding properties of ... | 2007 | 17535803 |
| the kdp-atpase system and its regulation. | k+, the dominant intracellular cation, is required for various physiological processes like turgor homeostasis, ph regulation etc. bacterial cells have evolved many diverse k+ transporters to maintain the desired concentration of internal k+. in e.coli, the kdpatpase (comprising of the kdpfabc complex), encoded by the kdpfabc operon, is an inducible high-affinity k+ transporter that is synthesised under conditions of severe k+ limitation or osmotic upshift. the e.coli kdp expression is transcrip ... | 2007 | 17536175 |
| knockout of crtb or crti gene blocks the carotenoid biosynthetic pathway in deinococcus radiodurans r1 and influences its resistance to oxidative dna-damaging agents due to change of free radicals scavenging ability. | deinococcus radiodurans r1, a red-pigmented strain of the extremely radioresistant genus deinococcus, contains a major carotenoid namely deinoxanthin. the high resistance of this organism against the lethal actions of dna-damaging agents including ionizing radiation and ultraviolet light (uv) has been widely reported. however, the possible antioxidant role of carotenoids in this strain has not been completely elucidated. in this study, we constructed two colorless mutants by knockout of crtb and ... | 2007 | 17541775 |
| the chromophore structures of the pr states in plant and bacterial phytochromes. | the resonance raman spectra of the pr state of the n-terminal 65-kda fragment of plant phytochrome phya have been measured and analyzed in terms of the configuration and conformation of the tetrapyrroles methine bridges. spectra were obtained from phya adducts reconstituted with the natural chromophore phytochromobilin as well as phycocyanobilin and its isotopomers labeled at the terminal methine bridges through (13)c/(12)c and d/h substitution. upon comparing the resonance raman spectra of the ... | 2007 | 17545245 |
| purification, crystallization and preliminary x-ray crystallographic analysis of branched-chain aminotransferase from deinococcus radiodurans. | the branched-chain amino-acid aminotransferase (bcat), which requires pyridoxal 5'-phosphate (plp) as a cofactor, is a key enzyme in the biosynthetic pathway of the hydrophobic amino acids leucine, isoleucine and valine. drbcat from deinococcus radiodurans, which has a molecular weight of 40.9 kda, was crystallized using the hanging-drop vapour-diffusion method. according to x-ray diffraction data to 2.50 a resolution from a drbcat crystal, the crystal belongs to space group p2(1)2(1)2(1), with ... | 2007 | 17554170 |
| synthesis of a tetrasaccharide glycosyl glycerol. precursor to glycolipids of meiothermus taiwanensis atcc baa-400. | synthesis of a tetrasaccharide glycosyl glycerol, the core structure of glycoglycerolipid from meiothermus taiwanensis atcc baa-400, was described. a one-pot glycosylation with three components was employed as a key step. | 2007 | 17579454 |
| crystal structure and mutational study of recor provide insight into its mode of dna binding. | the crystal structure of the complex formed between deinococcus radiodurans recr and reco (drrecor) has been determined. in accordance with previous biochemical characterisation, the drrecor complex displays a recr:reco molecular ratio of 2:1. the biologically relevant drrecor entity consists of a heterohexamer in the form of two drreco molecules positioned on either side of the tetrameric ring of drrecr, with their ob (oligonucleotide/oligosaccharide-binding) domains pointing towards the interi ... | 2007 | 17581636 |
| characterization of aerobic bacterial and fungal microbiota on surfaces of historic scottish monuments. | twenty samples were taken from the inner or outer surfaces of stone monuments of six historic scottish buildings and ruins. biofilms developing on mineral substrates were analysed by in situ scanning electron microscopy and cultivation. various methods were used to characterize the isolates including automated ribotyping, rapd and sequencing of the 16s rrna gene for bacteria, and stereomicroscopy and sequencing of the internal transcribed spacers (its) for fungi. most samples contained microbes ... | 2007 | 17583461 |
| the crystal structure of the dps2 from deinococcus radiodurans reveals an unusual pore profile with a non-specific metal binding site. | the crystal structure of recombinant dps2 (drb0092, dna protecting protein under starved conditions) from the gram-positive, radiation-resistant bacterium deinococcus radiodurans has been determined in its apo and iron loaded states. like other members of the dps family, the bacterial drdps2 assembles as a spherical dodecamer with an outer shell diameter of 90 a and an interior diameter of 40 a. a total of five iron sites were located in the iron loaded structure, representing the first stages o ... | 2007 | 17583727 |
| transport and deposition of metabolically active and stationary phase deinococcus radiodurans in unsaturated porous media. | bioremediation is a cost-efficient cleanup technique that involves the use of metabolically active bacteria to degrade recalcitrant pollutants. to further develop this technique it is important to understand the migration and deposition behavior of metabolically active bacteria in unsaturated soils. unsaturated transport experiments were therefore performed using deinococcus radiodurans cells that were harvested during the log phase and continuously supplied with nutrients during the experiments ... | 2007 | 17593729 |
| deinococcus peraridilitoris sp. nov., isolated from a coastal desert. | three ionizing-radiation-resistant bacterial strains (designated kr-196, kr-198 and kr-200(t)) were isolated from a sample of arid soil collected from a coastal desert in chile. the soil sample was irradiated before serial dilution plating was performed using one-tenth-strength plate count agar. phylogenetic analysis of the 16s rrna gene sequences showed these organisms to represent a novel species of the genus deinococcus, having sequence similarities of 87.3-90.8 % with respect to recognized d ... | 2007 | 17625166 |
| involvement of a periplasmic protein kinase in dna strand break repair and homologous recombination in escherichia coli. | the involvement of signal transduction in the repair of radiation-induced damage to dna has been known in eukaryotes but remains understudied in bacteria. this article for the first time demonstrates a role for the periplasmic lipoprotein (yfgl) with protein kinase activity transducing a signal for dna strand break repair in escherichia coli. purified yfgl protein showed physical as well as functional interaction with pyrroloquinoline-quinone in solution and the protein kinase activity of yfgl w ... | 2007 | 17630970 |
| role of reca in dna damage repair in deinococcus radiodurans. | it has been shown previously that the reca protein of deinococcus radiodurans plays a unique role in the repair of dna damage in this highly dna damage-resistant organism. despite the high level of amino-acid identity, previous work has shown that escherichia coli reca does not complement d. radiodurans reca mutants, further suggesting the uniqueness of d. radiodurans reca. the work presented here shows that e. coli reca does in fact provide partial complementation to a d. radiodurans reca null ... | 2007 | 17645526 |
| ring-like nucleoid does not play a key role in radioresistance of deinococcus radiodurans. | the conclusion based on transmission electron microscopy, "the tightly packed ring-like nucleoid of the deinococcus radiodurans r1 is a key to radioresistance", has instigated lots of debates. in this study, according to the previous research of pprl's crucial role in radioresistance of d. radiodurans, we have attempted to examine and compare the nucleoid morphology differences among wild-type d. radiodurans r1 strain, pprf function-deficient mutant (yr1), and pprl function-complementary strains ... | 2007 | 17653675 |
| deinococcus cellulosilyticus sp. nov., isolated from air. | a pink-coloured bacterial strain, 5516j-15(t), was isolated from an air sample from jeju island, republic of korea. the organism was found to have resistance to uv radiation typical of members of the genus deinococcus, and it was placed within the radiation of the deinococcus on a phylogenetic tree based on 16s rrna gene sequences. strain 5516j-15(t) shared low 16s rrna gene sequence similarity (84.5-87.8 %) with deinococcus species, showing highest sequence similarity to deinococcus deserti vcd ... | 2007 | 17684237 |
| what is radiation's true target? | | 2007 | 17687429 |
| endophytic bacterial diversity in rice (oryza sativa l.) roots estimated by 16s rdna sequence analysis. | the endophytic bacterial diversity in the roots of rice (oryza sativa l.) growing in the agricultural experimental station in hebei province, china was analyzed by 16s rdna cloning, amplified ribosomal dna restriction analysis (ardra), and sequence homology comparison. to effectively exclude the interference of chloroplast dna and mitochondrial dna of rice, a pair of bacterial pcr primers (799f-1492r) was selected to specifically amplify bacterial 16s rdna sequences directly from rice root tissu ... | 2008 | 17690836 |
| enzymes involved in dna ligation and end-healing in the radioresistant bacterium deinococcus radiodurans. | enzymes involved in dna metabolic events of the highly radioresistant bacterium deinococcus radiodurans are currently examined to understand the mechanisms that protect and repair the deinococcus radiodurans genome after extremely high doses of gamma-irradiation. although several deinococcus radiodurans dna repair enzymes have been characterised, no biochemical data is available for dna ligation and dna endhealing enzymes of deinococcus radiodurans so far. dna ligases are necessary to seal broke ... | 2007 | 17705817 |
| isolation and characterization of dibenzofuran-degrading serratia marcescens from alkalophilic bacterial consortium of the chemostat. | alkalophilic bacterial consortium developed by continuous enrichment in the chemostat in presence of 4-chlorosalicylic acid as sole source of carbon and energy contained six bacterial strains, micrococcus luteus (csa101), deinococcus radiothilus (csa102), csa103 (burkholderia gladioli), alloiococcus otilis (csa104), micrococcus diversus (csa105), micrococcus luteus (csa106), identified by the biolog test method. the strains were tested for utilization of organic compounds in which one of the str ... | 2007 | 17710482 |
| recbc enzyme overproduction affects uv and gamma radiation survival of deinococcus radiodurans. | deinococcus radiodurans recovering from the effect of acute dose of gamma (gamma) radiation shows a biphasic mechanism of dna double strands breaks repair that involves an efficient homologous recombination. however, it shows higher sensitivity to near-uv (nuv) than escherichia coli and lacks recbc, a dna strand break (dsb) repair enzyme in some bacteria. recombinant deinococcus expressing the recbc genes of e. coli showed nearly three-fold improvements in near-uv tolerance and nearly 2 log cycl ... | 2008 | 17720630 |
| topoisomerase v relaxes supercoiled dna by a constrained swiveling mechanism. | topoisomerase v is a type i topoisomerase without structural or sequence similarities to other topoisomerases. although it belongs to the type i subfamily of topoisomerases, it is unrelated to either type ia or ib enzymes. we used real-time single-molecule micromechanical experiments to show that topoisomerase v relaxes dna via events that release multiple dna turns, employing a constrained swiveling mechanism similar to that for type ib enzymes. relaxation is powered by the torque in the superc ... | 2007 | 17804808 |
| unique diversity of carotenoid-producing bacteria isolated from misasa, a radioactive site in japan. | we obtained carotenoid-producing microorganisms at a high frequency from water samples collected at misasa (tottori, japan), a region known for its high natural radioactivity content. a comprehensive 16s rrna gene-based phylogenetic analysis revealed that the 104 potential carotenoid producers isolated from misasa could be classified into 38 different species belonging to seven bacterial classes (flavobacteria, sphingobacteria, alpha-proteobacteria, gamma-proteobacteria, deinococci, actinobacter ... | 2007 | 17828533 |
| isoforms of glucose 6-phosphate dehydrogenase in deinococcus radiophilus. | glucose 6-phosphate dehydrogenase (g6pdh, ec 1.1.1.49) in deinococcus radiophilus, an extraordinarily uv-resistant bacterium, was investigated to gain insight into its resistance as it was shown to be involved in a scavenging system of superoxide (o2-1) and peroxide (o2-2) generated by uv and oxidative stresses. d. radiophilus possesses two g6pdh isoforms: g6pdh-1 and g6pdh-2, both showing dual coenzyme specificity for nad and nadp. both enzymes were detected throughout the growth phase; however ... | 2007 | 17846585 |
| structural and enzymatic characterization of dr1281: a calcineurin-like phosphoesterase from deinococcus radiodurans. | we have determined the crystal structure of dr1281 from deinococcus radiodurans. dr1281 is a protein of unknown function with over 170 homologs found in prokaryotes and eukaryotes. to elucidate the molecular function of dr1281, its crystal structure at 2.3 a resolution was determined and a series of biochemical screens for catalytic activity was performed. the crystal structure shows that dr1281 has two domains, a small alpha domain and a putative catalytic domain formed by a four-layered struct ... | 2008 | 17847097 |
| diversity analysis of antagonists from rice-associated bacteria and their application in biocontrol of rice diseases. | to understand the diversity, taxonomy and antagonistic potential of rice-associated bacteria, and to discover new bacteria for biocontrol of rice foliar pathogens. | 2008 | 17850318 |
| a freeze-thaw method for disintegration of escherichia coli cells producing t7 lysozyme used in pbad expression systems. | the plysn plasmid containing the t7 lysozyme gene under control of the lac promoter was constructed to facilitate cell disintegration after expression of recombinant proteins in arabinose-induced expression systems. the usefulness of this plasmid was tested in escherichia coli top10 and e. coli lmg194 cells carrying pbadmhadgessb plasmid containing deinococcus geothermalis ssb protein gene under control of the arabad promoter. the results showed that low-level expression of t7 lysozyme did not i ... | 2007 | 17882320 |
| deinococcus geothermalis: the pool of extreme radiation resistance genes shrinks. | bacteria of the genus deinococcus are extremely resistant to ionizing radiation (ir), ultraviolet light (uv) and desiccation. the mesophile deinococcus radiodurans was the first member of this group whose genome was completely sequenced. analysis of the genome sequence of d. radiodurans, however, failed to identify unique dna repair systems. to further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second deinococcus species, the thermophile de ... | 2007 | 17895995 |
| extremely radiation-resistant mutants of a halophilic archaeon with increased single-stranded dna-binding protein (rpa) gene expression. | extremely halophilic archaea are highly resistant to multiple stressors, including radiation, desiccation and salinity. to study the basis of stress resistance and determine the maximum tolerance to ionizing radiation, we exposed cultures of the model halophile halobacterium sp. nrc-1 to four cycles of irradiation with high doses of 18-20 mev electrons. two independently obtained mutants displayed an ld(50) > 11 kgy, which is higher than the ld(50) of the extremely radiation-resistant bacterium ... | 2007 | 17903038 |
| x-ray structures of two proteins belonging to pfam duf178 revealed unexpected structural similarity to the duf191 pfam family. | pfam is a comprehensive collection of protein domains and families, with a range of well-established information including genome annotation. pfam has two large series of functionally uncharacterized families, known as domains of unknown function (dufs) and uncharacterized protein families (upfs). | 2007 | 17908300 |
| activity, stability and structural studies of lactate dehydrogenases adapted to extreme thermal environments. | lactate dehydrogenase (ldh) catalyzes the conversion of pyruvate to lactate with concomitant oxidation of nadh during the last step in anaerobic glycolysis. in the present study, we present a comparative biochemical and structural analysis of various ldhs adapted to function over a large temperature range. the enzymes were from champsocephalus gunnari (an antarctic fish), deinococcus radiodurans (a mesophilic bacterium) and thermus thermophilus (a hyperthermophilic bacterium). the thermodynamic ... | 2007 | 17936781 |
| [construction of a dps mutant and its functional analysis in deinococcus radiodurans]. | dps (dna protection during starvation) is a member of the iron-binding protein family in prokaryotes. it has been shown previously that dps possesses ferroxidase activity and the ability to sequester iron that seems to protect dna from oxidative damage. based on the method of polymerase chain reaction and homologous genetic recombination in vivo, the gene (drb0092) encoding a dps protein homology in the extremely radioresistant bacterium deinococcus radiodurans was deleted from the wild type str ... | 2007 | 17944359 |
| crystal structure of the nadh:quinone oxidoreductase wrba from escherichia coli. | the flavoprotein wrba, originally described as a tryptophan (w) repressor-binding protein in escherichia coli, has recently been shown to exhibit the enzymatic activity of a nadh:quinone oxidoreductase. this finding points toward a possible role in stress response and in the maintenance of a supply of reduced quinone. we have determined the three-dimensional structure of the wrba holoprotein from e. coli at high resolution (1.66 a), and we observed a characteristic, tetrameric quaternary structu ... | 2007 | 17951395 |
| the clppx protease is required for radioresistance and regulates cell division after gamma-irradiation in deinococcus radiodurans. | protein degradation in bacteria is involved in diverse cellular responses to environmental stimuli and in removing potentially toxic damaged proteins or protein aggregates. atp-dependent proteases play a key role in these processes. here, we have individually inactivated all the atp-dependent proteases belonging to the clp or lon families in deinococcus radiodurans. the mutants were tested for survival after gamma-irradiation and for sensitivity to the trna analogue puromycin in order to assess ... | 2007 | 17986186 |
| towards understanding the extreme radiation resistance of ustilago maydis. | ustilago maydis is a phytopathogenic fungus exhibiting extreme resistance to uv and ionizing radiation. the molecular mechanisms underlying this resistance are as yet unknown. the recently determined genome sequence was examined for clues to the radiation resistance, focusing on proteins in homologous recombination, but there was little that was unusual about them. furthermore, by comparison, its recombinational repair system seems to be only minimally related to the extended synthesis-dependent ... | 2007 | 17997098 |
| a novel chromatography system to isolate active ribosomes from pathogenic bacteria. | we have developed a novel chromatography for the rapid isolation of active ribosomes from bacteria without the use of harsh conditions or lengthy procedures that damage ribosomes. ribosomes interact with an alkyl linker attached to the resin, apparently through their rna component. examples are given with ribosomes from escherichia coli, deinococcus radiodurans, and with clinical isolates of streptococcus pneumoniae and methicillin-resistant staphylococcus aureus (mrsa). the ribosomes obtained b ... | 2008 | 17998293 |
| "bring to lab" of 19 novel species among 60 isolates retrieved from a freshwater pond. | we report here on the cultivation of numerous novel bacterial species from a eutrophic freshwater pond. a total of 60 strains, 15 strains per each culture medium, were obtained from the surface of a eutrophic freshwater pond by employing a conventional dilution-plating method with four different kinds of culture media, including r2a, 1/10r2a, pca, and 1/10pca. among the 60 strains isolated, 27 strains showed less than 97% 16s rrna gene sequence similarities to validly published species, and thus ... | 2007 | 18051369 |
| degradation of phenanthrene on plant leaves by phyllosphere bacteria. | the activity of phyllosphere bacteria in the degradation of phenanthrene was investigated as a mechanism for the removal of atmospheric phenanthrene after its deposition on plant leaves. initially, leaf samples of six plant species were collected from two roadsides in bangkok to determine the presence of phenanthrene-degrading bacteria. the numbers of phenanthrene-degrading phyllosphere bacteria were varied and ranged from 3.5 x 10(4) to 1.95 x 10(7) cfu/g, in which the highest number was found ... | 2007 | 18057816 |
| [microbial diversity in scorpion intestine (buthus martensii karsch)]. | scorpion is an important officinal animal, and has a high nutritional value. in this study, the culture-independent and culture-dependent methods were used to investigate the microbial diversity in the scorpion's intestine. results based on culture-independent method showed the bacteria to be related to alpha, beta, gamma-proteobacteria. bacteria isolated by the culture-dependent method were high g + c, gram-positive bacteria. the genera enterobacter, serratia and ochrobactrum were detected by b ... | 2007 | 18062268 |
| biophysical analysis of thermus aquaticus single-stranded dna binding protein. | due to their involvement in processes such as dna replication, repair, and recombination, bacterial single-stranded dna binding (ssb) proteins are essential for the survival of the bacterial cell. whereas most bacterial ssb proteins form homotetramers in solution, dimeric ssb proteins were recently discovered in the thermus/deinococcus group. in this work we characterize the biophysical properties of the ssb protein from thermus aquaticus (taqssb), which is structurally quite similar to the tetr ... | 2008 | 18065449 |
| identification of signature proteins that are distinctive of the deinococcus-thermus phylum. | the members of the deinococcus-thermus phylum, which include many species that are resistant to extreme radiation, as well as several thermophiles, have been recognized solely on the basis of their branching patterns in 16s rrna and other phylogenetic trees. no biochemical or physiological characteristic is currently known that is unique to this group of species. to identify genes/proteins that are exclusive of this group of species, systematic protein basic local alignment tool (blastp) searche ... | 2007 | 18076002 |
| problems with the current deinococcal hypothesis: an alternative theory. | all theories related to the evolution of deinococcus radiodurans have a common denominator: the strong positive correlation between ionizing-radiation resistance and desiccation tolerance. currently, the widespread hypothesis is that d. radiodurans' ionizing-radiation resistance is a consequence of this organism's adaptation to desiccation (desiccation adaptation hypothesis). here, we draw attention to major discrepancy that has emerged between the "desiccation adaptation hypothesis" and recent ... | 2007 | 18087756 |
| deinococcus misasensis and deinococcus roseus, novel members of the genus deinococcus, isolated from a radioactive site in japan. | two gamma- and uv-radiation resistant, gram-positive, red- or pink-pigmented, rod-shaped, strictly aerobic, oxidase- and catalase-positive bacterial strains, tdma-25t and tdma-uv51t, were isolated from fresh water collected at misasa, a radioactive site in japan. phylogenetic analysis based on 16s rrna gene sequences placed both in a distinct lineage in the family deinococcaceae, and the highest degrees of sequence similarity determined belonged to deinococcus maricopensis lb-34t (88.8-89.3%), d ... | 2008 | 18096345 |
| mutational analysis of deinococcus radiodurans bacteriophytochrome reveals key amino acids necessary for the photochromicity and proton exchange cycle of phytochromes. | the ability of phytochromes (phy) to act as photointerconvertible light switches in plants and microorganisms depends on key interactions between the bilin chromophore and the apoprotein that promote bilin attachment and photointerconversion between the spectrally distinct red light-absorbing pr conformer and far red light-absorbing pfr conformer. using structurally guided site-directed mutagenesis combined with several spectroscopic methods, we examined the roles of conserved amino acids within ... | 2008 | 18192276 |
| electrochemical inactivation of paper mill bacteria with mixed metal oxide electrode. | in this study electrochemical inactivation of selected bacteria living in paper mill circulating waters was investigated. three aerobic bacteria species (deinococcus geothermalis, pseudoxanthomonas taiwanensis and meiothermus silvanus) were inactivated effectively (>2 log) at a mixed metal oxide (mmo) electrode in 3 min. the influence of parameters, such as current density and initial ph or chloride concentration of synthetic paper machine water (spw) on the inactivation efficiency were studied. ... | 2008 | 18206301 |
| drrra: a novel response regulator essential for the extreme radioresistance of deinococcus radiodurans. | two-component systems are predominant signal transduction pathways in prokaryotes, and also exist in many archaea as well as some eukaryotes. a typical tcs consists of a histidine kinase and a cognate response regulator. in this study, a novel gene encoding a response regulator (we designate it drrra) is identified to be essential for the extreme radioresistance of deinococcus radiodurans. drrra null mutant (we designate it mr) is sensitive to gamma-radiation compared with the wild-type strain. ... | 2008 | 18208531 |
| plant-pathogenic streptomyces species produce nitric oxide synthase-derived nitric oxide in response to host signals. | nitric oxide (no) is a potent intercellular signal for defense, development, and metabolism in animals and plants. in mammals, highly regulated nitric oxide synthases (noss) generate no. nos homologs exist in some prokaryotes, but direct evidence for no production by these proteins has been lacking. here, we demonstrate that a nos in plant-pathogenic streptomyces species produces diffusible no. nos-dependent no production increased in response to cellobiose, a plant cell wall component, and occu ... | 2008 | 18215772 |
| reco is essential for dna damage repair in deinococcus radiodurans. | here we present direct evidence for the vital role of reco in deinococcus radiodurans's radioresistance. a reco null mutant was constructed using a deletion replacement method. the mutant exhibited a growth defect and extreme sensitivity to irradiation with gamma rays and uv light. these results suggest that dna repair in this organism occurs mainly via the recf pathway. | 2008 | 18223077 |
| decontamination effects of low-temperature plasma generated by corona discharge. part ii: new insights. | the second part of our paper presents the results of experiments with the decontamination of surfaces by low-temperature plasma generated by corona discharge in air at atmospheric pressure. a simple device is described and the effects of the corona discharge on model microorganisms, viz. the yeast candida albicans, gram-negative bacteria escherichia coli, enterobacter aerogenes, neisseria sicca, stenotrophomonas maltophilia, gram-positive bacteria deinococcus radiodurans, enterococcus faecium, s ... | 2007 | 18225640 |