| sequence heterogeneity between the two genes encoding 16s rrna from the halophilic archaebacterium haloarcula marismortui. | the halophilic archaebacterium, haloarcula marismortui, contains two nonadjacent ribosomal rna operons, designated rrna and rrnb, in its genome. the 16s rrna genes within these operons are 1472 nucleotides in length and differ by nucleotide substitutions at 74 positions. the substitutions are not uniformly distributed but rather are localized within three domains of 16s rrna; more than two-thirds of the differences occur within the domain bounded by nucleotides 508 and 823. this domain is known ... | 1992 | 1372578 |
| the alpha-operon equivalent genome region in the extreme halophilic archaebacterium haloarcula (halobacterium) marismortui. | the genome region of the extreme halophilic archaebacterium haloarcula marismortui equivalent to the alpha-operon of escherichia coli has been characterized. in h. marismortui, the alpha-operon was found to be located immediately upstream from the s9 gene cluster. the gene order in the halobacterial alpha-operon, given according to the gene products, is trna(ser), hmas13, hmas4, hmas11, and hmarp alpha. compared to the corresponding operon from e. coli, the halobacterial gene organization differ ... | 1992 | 1376318 |
| halophilic malate dehydrogenase--a case history of biophysical investigations: ultracentrifugation, light-, x-ray- and neutron scattering. | halophilic malate dehydrogenase (hmdh) from haloarcula marismortui has been isolated, purified and characterized by biochemical and biophysical solution studies. a stabilization mechanism at extremely high concentrations of salt, based on the formation of co-operative hydrate bonds between the protein and hydrated salt ions, was suggested from thermodynamic analysis of native enzyme solutions. recently the gene coding for hmdh was isolated and sequenced and an active enzyme cloned (f. cendrin, j ... | 1992 | 1445401 |
| nucleotide sequence of the genes for ribosomal proteins hs15 and hsh from haloarcula marismortui: an archaeon-specific gene cluster. | the nucleotide sequences of the genes for two ribosomal proteins, hs15 and hsh, from the archaeon haloarcula marismortui, have been determined. the genes were found in a cluster together with another open reading frame with a probable regulatory function. hs15 and hsh have counterparts in eucarya. hs15 is significantly homologous to s19 from frog (xenopus laevis). hsh is related to s37 from yeast (saccharomyces cerevisiae) and s27 from fly (drosophila melanogaster), as well as to other members o ... | 1992 | 1468549 |
| the genes for ribosomal protein l15 and the protein equivalent to secy in the archaebacterium haloarcula (halobacterium) marismortui. | the nucleotide sequences of the l15 gene and the secy gene, which form the last two genes of the s10/spc-operon region of haloarcula marismortui, have been determined. the hmal15 protein sequence translated from the dna is 164 amino acids long, revealing 10 amino acids more at the c-terminus than the published protein sequence. the deduced hmasecy protein sequence has 487 amino acids and shows significant homology to its counterparts in methanococcus vannielii and escherichia coli. the gene orde ... | 1992 | 1543743 |
| transformation of members of the genus haloarcula with shuttle vectors based on halobacterium halobium and haloferax volcanii plasmid replicons. | we have stably transformed both haloarcula vallismortis and haloarcula hispanica with the halobacterium-escherichia coli shuttle vectors pwl102 (based on the haloferax volcanii phv2 replicon) and pubp2 (based on the halobacterium halobium phh1 replicon). haloferax volcanii, halobacterium halobium, and haloarcula vailismortis are equally distant from one another and span the phylogenetic depth of the halophilic archaea; thus, these vectors may be generally useful for the halophiles. both haloarcu ... | 1992 | 1732202 |
| organization and nucleotide sequence of ten ribosomal protein genes from the region equivalent to the spectinomycin operon in the archaebacterium halobacterium marismortui. | the nucleotide sequence has been determined of a 4700 bp region from a ribosomal protein gene cluster of halobacterium marismortui (haloarcula marismortui), which is equivalent to part of the spectinomycin operon of escherichia coli. the genes were localized on the recombinant lambda embl3 clone pp*7, which also contains several other ribosomal protein genes from the dna region in h. marismortui equivalent to the linked s10/spc operon. the genes analysed encode ten ribosomal proteins, namely hma ... | 1991 | 1832208 |
| halobacterial s9 operon. three ribosomal protein genes are cotranscribed with genes encoding a trna(leu), the enolase, and a putative membrane protein in the archaebacterium haloarcula (halobacterium) marismortui. | in the eubacterium escherichia coli the genes for the ribosomal proteins l13 and s9 form an operon consisting of two genes. the corresponding operon of the archaebacterium haloarcula marismortui (halobacterium marismortui was recently reassigned to the genus haloarcula [oren, a., ginzburg, m., ginzburg, b. z., hochstein, l. i., and volcani, b. e. (1990) int. j. syst. bacteriol. 40, 209-210] and is now called haloarcula marismortui) which is presented here, is much larger encoding three ribosomal ... | 1991 | 1840597 |
| an unusual class i (schiff base) fructose-1,6-bisphosphate aldolase from the halophilic archaebacterium haloarcula vallismortis. | an electrophoretically homogeneous class i (schiff base) alsolase has been isolated for the first time from the archaebacterial halophile haloarcula (halobacterium) vallismortis. the aldolase was characterized with respect to its molecular mass, amino acid composition, salt dependency, immunological cross-reactivity and kinetic properties. the subunit mass of aldolase is 27 kda, which is much smaller than other class i aldolases. by the gel filtration method, the molecular mass of the halobacter ... | 1991 | 1900049 |
| characterization and preliminary attempts for derivatization of crystals of large ribosomal subunits from haloarcula marismortui diffracting to 3 a resolution. | an improved form of crystals of large (50 s) ribosomal subunits from haloarcula marismortui, formally named halobacterium marismortui, diffracting to 3 a resolution, has been obtained by the addition of 1 mm-cd2+ to the crystallization medium, which contained more than 1.9 m of other salts. the improved crystals, grown from functionally active particles to an average size of 0.3 mm x 0.3 mm x 0.08 mm, are isomorphous with the previously reported ones, which diffracted to 4.5 a. they are of space ... | 1991 | 1942063 |
| extracellular ca2(+)-dependent inducible alkaline phosphatase from extremely halophilic archaebacterium haloarcula marismortui. | when starved of inorganic phosphate, the extremely halophilic archaebacterium haloarcula marismortui produces the enzyme alkaline phosphatase and secretes it to the medium. this inducible extracellular enzyme is a glycoprotein whose subunit molecular mass is 160 kda, as estimated by sodium dodecyl sulfate-gel electrophoresis. the native form of the enzyme is heterogeneous and composed of multiple oligomeric forms. the enzymatic activity of the halophilic alkaline phosphatase is maximal at ph 8.5 ... | 1990 | 2123861 |
| amino acid sequences of the ribosomal proteins hl30 and hmal5 from the archaebacterium halobacterium marismortui. | the complete amino acid sequences of the ribosomal proteins hl30 and hmal5 from the archaebacterium halobacterium marismortui were determined. protein hl30 was found to be acetylated at its n-terminal amino acid and shows homology to the eukaryotic ribosomal proteins yl34 from yeast and rl31 from rat. protein hmal5 was homologous to the protein l5 from escherichia coli and bacillus stearothermophilus as well as to yl16 from yeast. hmal5 shows more similarities to its eukaryotic counterpart than ... | 1990 | 2198942 |
| evidence for an additional archaebacterial gene cluster in halobacterium marismortui encoding ribosomal proteins hl46e and hl30. | a small and extremely basic ribosomal protein (hl46e) has been purified from halobacterium marismortui using reversed-phase high-performance liquid chromatography (hplc). the amino acid sequence of the protein was determined by automated n-terminal and internal sequence analysis. comparison of this sequence with other ribosomal protein sequences from eubacteria, archaebacteria and eukaryotes revealed a strong homology to sl46e from sulfolobus solfataricus, yeal46 from yeast and rl39 from rat. no ... | 1990 | 2207169 |
| extended n-terminal sequencing of proteins of archaebacterial ribosomes blotted from two-dimensional gels onto glass fiber and poly(vinylidene difluoride) membrane. | previously uncharacterized proteins from intact ribosomes and ribosomal subunits of the extreme halophile halobacterium marismortui (haloarcula marismortui) were isolated and separated by high-resolution two-dimensional electrophoresis (2de). n-terminal amino acid sequences of 14 of these acidic large-subunit proteins were obtained by direct blotting of the separated proteins from two-dimensional electrophoresis gels to sequencer-stable supports followed by excision of the protein spots and sequ ... | 1988 | 3196689 |
| a secy homologous gene in the crenarchaeon sulfolobus acidocaldarius. | the nucleotide sequence of an open reading frame, located upstream of the gene for adenylate kinase, was determined in the thermoacidophile crenarchaeon sulfolobus acidocaldarius. data bank searches identified the sequence as a secy homologous gene. the dna derived protein sequence of total 463 amino acids contains 10 hydrophobic domains. a sequence alignment with other prokaryotic and eukaryotic secy sequences reveals significant homology, but the secy primary sequence of s. acidocaldarius show ... | 1995 | 7495856 |
| mutation at a single acidic amino acid enhances the halophilic behaviour of malate dehydrogenase from haloarcula marismortui in physiological salts. | in a statistical analysis of the amino acid compositions of 26 halophilic proteins, 24 showed an increase in acidic amino acids and a decrease in basic ones when compared to their non-halophilic homologues. the role of acidic residues in halophilic adaptation was investigated by site-directed mutagenesis of malate dehydrogenase (maldh) from haloarcula marismortui. in all of 40 non-halophilic homologous proteins, the position aligned with e243 in halophilic maldh is occupied by a non-acidic amino ... | 1995 | 7601139 |
| [interaction of halobacteria and cyanobacteria in a halophilic cyanobacterial community]. | from cyanobacterial mat, 36 strains of extremely halophilic archaebacteria were isolated. basing on phenotypic and genotypic characteristics, two frequently occurring organisms among these strains were identified as haloarcula japonica and halobacterium distributum. metabiotic interaction between halophilic archaea and microcoleus chthonoplastes, the primary organic matter producer, was demonstrated. it was shown that m. chthonoplastes secretes acids of tricarboxylic acid cycle into the medium a ... | 1995 | 7616881 |
| amino acid sequence of the ribosomal protein hs23 from the halophilic haloarcula marismortui and homology studies to other ribosomal proteins. | the ribosomal protein hs23 from the 30s subunit of the extreme halophilic haloarcula marismortui, belonging to the group of archaea, was isolated either by rp-hlplc or two-dimensional polyacrylamide gel electrophoresis. the complete amino acid sequence was determined by automated n-terminal microsequencing. the protein consists of 123 residues with a corresponding molecular mass of 12,552 da as determined by electrospray mass spectroscopy; the pi is 11.04. homology studies reveal similarities to ... | 1995 | 7662106 |
| the primary structure of sensory rhodopsin ii: a member of an additional retinal protein subgroup is coexpressed with its transducer, the halobacterial transducer of rhodopsin ii. | the blue-light receptor genes (sopii) of sensory rhodopsin (sr) ii were cloned from two species, the halophilic bacteria haloarcula vallismortis (vsr-ii) and natronobacterium pharaonis (psr-ii). upstream of both sopii gene loci, sequences corresponding to the halobacterial transducer of rhodopsin (htr) ii were recognized. in n. pharaonis, psopii and phtrii are transcribed as a single transcript. comparison of the amino acid sequences of vhtr-ii and phtr-ii with htr-i and the chemotactic methyl-a ... | 1995 | 7708770 |
| life in unusual environments: progress in understanding the structure and function of enzymes from extreme halophilic bacteria. | extreme halophilic archaea are saturated with salt and the intracellular electrolyte concentration exceeds that of the extracellular environment. enzymes and other proteins from extreme halophilic archaea have been purified for many years and studied by biochemical and biophysical solution methodologies. they are active and stable at multimolar salt concentrations and denature below 2 to 3 m nacl or kcl. adaptation to these high concentrations of salt, genetic and evolutionary aspects, and the p ... | 1995 | 7726549 |
| diversity of lactate metabolism in halophilic archaea. | d-lactate is readily used as a substrate for the growth of species of halophilic archaea belonging to the genera haloferax and haloarcula. l-lactate was used by haloferax species (haloferax volcanii, haloferax mediterranei) only when a substantial concentration of the d-isomer was also present in the medium. on the enzymatic level, considerable diversity was found in the lactate metabolism of the different representatives of the halobacteriaceae. at least three types of lactate dehydrogenases we ... | 1995 | 7736359 |
| the light-driven proton pump, cruxrhodopsin-2 in haloarcula sp. arg-2 (br+, hr-), and its coupled atp formation. | haloarcula sp. arg-2, a natural bacterial isolate from andes heights, has a light-driven proton pump but not a light-driven anion pump. we have cloned and sequenced the gene encoding for the proton pump which has been named cruxrhodopsin-2. the gene consists of 768 bp encoding 255 amino acids with a molecular mass of 27,544 da. the deduced amino acid sequence of cruxrhodopsin-2 is 77%, 50%, 48% and 48% identical to those of cruxrhodopsin-1, bacteriorhodopsin, archaerhodopsin-1 and archaerhodopsi ... | 1994 | 7803445 |
| construction of composite transposons for halophilic archaea. | transposons with selectable marker genes (e.g., antibiotic resistance) have been extremely useful tools in bacterial genetics but have not been found naturally in archaea. we constructed synthetic transposons consisting of halobacterial ish elements (ish2, ish26, or ish28) flanking a mevinolin resistance determinant. introduction of these constructs into haloferax volcanii cells can produce drug-resistant transformants through homologous recombination between the plasmid hmga gene and the chromo ... | 1994 | 7804904 |
| enzyme diversity in halophilic archaea. | the halophilic archaea display a considerable extent of enzyme diversity. the presence or absence of certain enzymatic activities is closely linked with the taxonomic status of the strains investigated. thus, halobacterium species such as hb. salinarium, hb. halobium, and hb. cutirubrum differ from most other halobacteriaceae tested by the possession of an nad(+)-dependent glycerol dehydrogenase, by the absence of methylglyoxal synthase activity, and the ability of fermentative growth on arginin ... | 1994 | 7873098 |
| characterization of 1-phosphofructokinase from halophilic archaebacterium haloarcula vallismortis. | 1-phosphofructokinase (ec 2.7.1.56) (1pfk) was purified and characterized for the first time from an archaebacterial halophile haloarcula vallismortis. the purification procedure involving (nh4)2so4 fractionation, (nh4)2so4-mediated chromatography on sepharose 4b, cm-cellulose chromatography, hydrophobic chromatography on phenyl sepharose and adsorption chromatography on hydroxylapatite yielded a preparation with a specific activity of 128 and 100-fold purification. from gel filtration and sucro ... | 1994 | 7918573 |
| the asialoglycoprotein receptor is associated with a tyrosine kinase in hepg2 cells. | the asialoglycoprotein (asgp) receptor undergoes constitutive endocytosis in hepg2 cells, which is regulated by tyrosine kinase activity (fallon, r. j., danaher, m., saylors, r. l., and saxena, a. (1994) j. biol. chem. 269, 11011-11017). in this study we show that the receptor copurifies with a tyrosine kinase activity, as defined by tyrosine phosphorylation of an exogenous substrate (reduced carboxyamidomethylated and maleylated lysozyme). analysis of cells transfected with one subunit of the a ... | 1994 | 7929394 |
| purification and properties of a halophilic catalase-peroxidase from haloarcula marismortui. | a heme protein, hcp, from the extreme halophile, haloarcula marismortui, showing both peroxidatic and catalatic activity has been purified and characterized as a catalase-peroxidase. catalatic activity is enhanced by molar concentrations of nacl or (nh4)2so4, while peroxidase activity decreases with increasing salt concentration. optimal ph values are 6.0 for peroxidatic activity assayed in absence of nacl and 7.5 for catalatic activity assayed in molar concentrations of nacl. the two activities ... | 1994 | 7947969 |
| the novel ion pump rhodopsins from haloarcula form a family independent from both the bacteriorhodopsin and archaerhodopsin families/tribes. | extreme halophiles newly collected from argentine salt flats were characterized, in one of which, haloarcula (sp. arg-1), light-driven retinal protein ion pumps were found. the proton pump, cruxrhodopsin-1, shows amino acid sequence homologies of 52% to bacteriorhodopsin and 48% to archaerhodopsin-1. the anion pump, cruxhalorhodopsin-1, identified partially as a 394bp polymerase chain reaction product, shows homologies of 70% to halorhodopsin, and 72% to pharaonis halorhodopsin. the ion pumps (a ... | 1994 | 7979388 |
| stability against denaturation mechanisms in halophilic malate dehydrogenase "adapt" to solvent conditions. | malate dehydrogenase from haloarcula marisomortui (hmdh) is active, soluble and mildly unstable in an unusually wide range of salt conditions and temperatures, making it a particularly interesting model for the study of solvent effects on protein stability. its denaturation (loss of activity due to concomitant dissociation and unfolding) kinetics was studied as a function of temperature and concentration of nacl, potassium phosphate or ammonium sulphate in h2o or 2h2o. a transition-state-theory ... | 1994 | 7990132 |
| comparative studies on ion pumps of the bacterial rhodopsin family. | bacteriorhodopsin (proton pump), halorhodopsin (anion pump), sensory rhodopsin and phoborhodopsin (photosensors) are found in halobacterium salinarium (halobium). in some other strains, other sets of rhodopsin pumps and sensors have been found. here, these bacterial rhodopsins are classified according to their amino acid sequence homologies, and their host genera are assigned on the basis of 16s rrna sequence comparison. haloarcula is the host for cruxrhodopsins and a new genus (temporarily "hal ... | 1994 | 8011934 |
| crystallography of halophilic ribosome: the isolation of an internal ribonucleoprotein complex. | crystals of 50s ribosomal subunits from haloarcula marismortui diffracting to 2.9 a resolution were grown. because of their large unit cells and the extremely weak diffracting power, almost all x-ray crystallographic analysis of these crystals must be performed with intense synchrotron radiation. at ambient temperature, all ribosomal crystals decay upon the first instance of x-irradiation. to overcome this severe sensitivity, procedures for data collection at cryo temperature were developed. und ... | 1994 | 8011938 |
| aminoacyl-trna synthetases from haloarcula marismortui: an evidence for a multienzyme complex in a procaryotic system. | aminoacyl-trna synthetases in halophilic archaebacterium haloarcula marismortui form a high molecular weight multienzyme complex which is resistant to dissociation when subjected to gel filtration, ion exchange, ammonium sulfate mediated and hydroxyapatite chromatography. functional and structural aspects of the aminoacyl-trna synthetase complex formation are discussed. | 1994 | 8061624 |
| ketohexokinase (atp:d-fructose 1-phosphotransferase) from a halophilic archaebacterium, haloarcula vallismortis: purification and properties. | ketohexokinase (atp:d-fructose 1-phosphotransferase [ec 2.7.1.3]), detected for the first time in a prokaryote, i.e., the extreme halophile haloarcula vallismortis, was isolated and characterized from the same archaebacterium. this enzyme was characterized with respect to its molecular mass, amino acid composition, salt dependency, immunological cross-reactivity, and kinetic properties. gel filtration and sucrose density gradient centrifugation revealed a native molecular mass of 100 kda for hal ... | 1994 | 8071229 |
| [new species of haloarcula]. | three strains of pleomorphic halobacteria (a5, b2 and b-b2) were isolated from salt lakes of xinjiang, china. based on the bergey's manual of systematic bacteriology, volume 3 (1989) and the analytical results of polar lipids, the three strains could be included in the genus haloarcula. but since they differ from normally accepted two species of this genus in cell shape and physiological and biochemical features, it is suggested that the three strains belong to a new species, called haloarcu la ... | 1994 | 8073765 |
| comparative analysis of the protein components from 5s rrna.protein complexes of halophilic archaebacteria. | the 5s rna.protein complexes have been isolated from the 50s subunit of the halophilic archaebacteria halobacterium cutirubrum, halobacterium halobium, halobacterium salinarium, haloferax mediterranei, haloferax volcanii and haloarcula marismortui. the 50s subunits from most of the halophiles released a multiprotein ribonucleoprotein particle similar to that previously observed with the h. cutirubrum 5s rna.protein complex, which contained proteins from the l5 and l18 ribosomal protein families. ... | 1994 | 8174557 |
| ch2, a novel halophilic archaeon from an australian solar saltern. | a novel halophilic archaeon, strain ch2, was isolated from a marine solar saltern in geelong, australia. the fact that this organism had a dam-methylated genome suggested that it is closely related to the taxon that includes halobacterium saccharovorum, halobacterium sodomense, and halobacterium trapanicum. a sequence analysis of the 16s rrna gene (ch2 has three copies of this gene) showed that ch2 is phylogenetically equidistant from the genera haloarcula and haloferax and closely related to h. ... | 1993 | 8198622 |
| [amplification of 16s rdnas from halobacteria by means of pcr technique]. | the 16s rdnas have been amplified from four halobacteria haloarcula vallismortis (em201), haloferax denitrificans (em303). a5 and b2 through a set of specific primers using the pcr technique. the molecule of the pcr products is about 1.47 kb. the hybridization results also show that these pcr products have dna homology with halobacteria. | 1994 | 8209549 |
| on the revised structure of the major phospholipid of halobacterium salinarium. | recent fast atom bombardment-mass spectrometry (fabms) studies (tsujimoto, k., yorimitsu, s., takahashi, t. and ohashi, m. (1989) j. chem. commun. 668-670; frederickson, h.l., de leeuw, j.w., tas, a.c., van der greef, j., lavos, g.f. and boon, j.j. (1989) biomed. environ. mass. spectrom. 18, 96-105; kloppel, k.d. and fredrickson, h.l. (1991) j. chromatogr. 562, 369-376) have indicated that the structure of the major phospholipid of halobacterium salinarium (formerly halobacterium cutirubrum) is ... | 1993 | 8334149 |
| partial sequence of the gene for a serine protease from a halophilic archaeum haloferax mediterranei r4, and nucleotide sequences of 16s rrna encoding genes from several halophilic archaea. | a part of the gene coding for a halophilic serine protease from a halophilic archaeum haloferax mediterranei r4 was amplified by pcr and its 672 nucleotide sequence was determined. tentative translation to the amino acid sequence suggested that the enzyme was quite similar to halolysin produced by another halophilic archaeum strain 172p1. nucleotide sequences of 16s rrna encoding genes from 9 halophilic archaea were determined. alignment of 19 sequences known so far showed that there are more th ... | 1993 | 8335078 |
| n-terminal modification and amino-acid sequence of the ribosomal protein hmas7 from haloarcula marismortui and homology studies to other ribosomal proteins. | the ribosomal protein hmas7 from the 30s subunit of the extreme halophilic archaeum haloarcula marismortui was isolated by semi-preparative rp-hplc. the complete amino-acid sequence of this protein was determined by automated microsequence analysis of appropriate peptide fragments from several proteinase digests. the entire protein consists of 205 amino acids with a corresponding molecular mass of 22580 da. the modification at the amino-terminal amino acid was deblocked so that the n-terminal am ... | 1993 | 8338632 |
| localization of proteins hl29 and hl31 from haloarcula marismortui within the 50 s ribosomal subunit by chemical crosslinking. | isolated 50 s ribosomal subunits from the halophilic archaebacterium haloarcula marismortui were treated in situ with the homobifunctional and cleavable crosslinking reagent dithiobis(succinimidyl propionate) (12 a). several crosslinked complexes were obtained. among these were the protein pairs hmal4-hl29 and hmal18-hl31; hl29 and hl31 are ribosomal proteins without any equivalent in eubacterial ribosomes. the crosslinked protein pairs were isolated on a preparative scale by combining conventio ... | 1993 | 8345527 |
| characterization of the glyceraldehyde 3-phosphate dehydrogenase from the extremely halophilic archaebacterium haloarcula vallismortis. | glyceraldehyde 3-phosphate dehydrogenase (ec 1.2.1.12) from the extremely halophilic archaebacterium haloarcula vallismortis has been purified in a four step procedure to electrophoretic homogeneity. the enzyme is a tetramer with a relative molecular mass of 160,000. it is strictly nad(+)-dependent and exhibits its highest activity in 2 mol/l kcl at 45 degrees c. amino acid analysis and isoelectric focusing indicate an excess of acidic amino acids. two parts of the primary sequence are reported. ... | 1993 | 8352651 |
| halophilic class i aldolase and glyceraldehyde-3-phosphate dehydrogenase: some salt-dependent structural features. | aldolase and glyceraldehyde-3-phosphate dehydrogenase from the extremely halophilic archaebacterium haloarcula vallismortis are stable only in high concentrations of kcl present within the physiological environment. data concerning the structural changes in the two enzymes as a result of lowering of salt concentration and changes in ph were obtained by monitoring the intrinsic protein fluorescence in the presence of quenchers. when the kcl concentrations were lowered below 2 m or in the presence ... | 1993 | 8422383 |
| characterization of paralogous and orthologous members of the superoxide dismutase gene family from genera of the halophilic archaebacteria. | four species representing three genera of halophilic archaebacteria were examined for the presence of genomic sequences that encode proteins of the superoxide dismutase family. three species, halobacterium cutirubrum, halobacterium sp. strain grb, and haloferax volcanii, contain duplicated (paralogous) genes of the sod family; a fourth species, haloarcula marismortui, contains only a single gene. these seven genes were cloned and sequenced, and their transcripts were characterized by northern (r ... | 1993 | 8449865 |
| identification of cross-linked amino acids in the protein pair hmal23-hmal29 from the 50s ribosomal subunit of the archaebacterium haloarcula marismortui. | 50s ribosomal subunits from the extreme halophilic archaebacterium haloarcula marismortui were treated with the homobifunctional protein-protein cross-linking reagents diepoxybutane (4 a) and dithiobis(succinimidyl propionate) (12 a). the dominant product with both cross-linking reagents was identified on the protein level as hmal23-hmal29, which is homologous to the protein pair l23-l29 from escherichia coli [walleczek, j., martin, t., redl, b., stöffler-meilicke, m., & stöffler, g. (1989) bioc ... | 1993 | 8457554 |
| cloning, sequencing, and expression in escherichia coli of the gene coding for malate dehydrogenase of the extremely halophilic archaebacterium haloarcula marismortui. | the gene coding for the enzyme malate dehydrogenase (mdh) of the extremely halophilic archaebacterium haloarcula marismortui was isolated and sequenced. the enzyme is composed of 303 amino acids, and its molecular mass is 32,638 da. the deduced amino acid sequence of the enzyme was found to be more similar to the sequence of l-lactate dehydrogenase (l-ldh) from various sources than to the sequence of other mdhs. the structural gene was cloned in the escherichia coli expression vector pet11a, and ... | 1993 | 8476859 |
| hl35e and hla: primary structure of two very basic and cysteine-rich ribosomal proteins from haloarcula marismortui. | two small and very basic ribosomal proteins have been purified from the 50s ribosomal subunit of the archaebacterium haloarcula marismortui by rp-hplc. the complete primary structures of these two proteins, which we refer to as hl35e and hla, have been determined by protein chemical methods. both proteins are characterized by a high content of basic amino acids and the presence of two pairs of cysteines in each polypeptide chain, one of which resembles the c4-zinc-finger motif. comparison of the ... | 1993 | 8504167 |
| cartography of ribosomal proteins of the 30s subunit from the halophilic haloarcula marismortui and complete sequence analysis of protein hs26. | by two-dimensional polyacrylamide gel electrophoresis of 30s ribosomal subunit proteins (s proteins) from haloarcula marismortui we identified 27 distinct spots and analyzed all of them by protein sequence analysis. we demonstrated that protein hmas2 (hs2) is encoded by the open reading frame orfmsg and has sequence similarities to the s2 ribosomal protein family. the proteins hmas5 and hmas14 were identified as spots hs7 and hs21/hs22, respectively. protein hs4 was characterized by amino-termin ... | 1995 | 8529646 |
| insights into protein adaptation to a saturated salt environment from the crystal structure of a halophilic 2fe-2s ferredoxin. | haloarcula marismortui is an archaebacterium that flourishes in the world's saltiest body of water, the dead sea. the cytosol of this organism is a supersaturated salt solution in which proteins are soluble and active. the crystal structure of a 2fe-2s ferredoxin from h. marismortui determined at 1.9 a is similar to those of plant-type 2fe-2s ferredoxins of known structure, with two important distinctions. the entire surface of the protein is coated with acidic residues except for the vicinity o ... | 1996 | 8612076 |
| higher-plant chloroplast and cytosolic 3-phosphoglycerate kinases: a case of endosymbiotic gene replacement. | previous studies indicated that plant nuclear genes for chloroplast and cytosolic isoenzymes of 3-phosphoglycerate kinase (pgk) arose through recombination between a preexisting gene of the eukaryotic host nucleus for the cytosolic enzyme and an endosymbiont-derived gene for the chloroplast enzyme. we readdressed the evolution of eukaryotic pgk genes through isolation and characterisation of a pgk gene from the extreme halophilic, photosynthetic archaebacterium haloarcula vallismortis and analys ... | 1996 | 8616244 |
| viruses, plasmids and other genetic elements of thermophilic and hyperthermophilic archaea. | we review and update the work on genetic elements, e.g., viruses and plasmids (exluding is elements and transposons) in the kingdom crenarchaeota (thermoproteales and sulfolobales) and the orders thermococcales and thermoplasmales in the kingdom euryarchaeota of the archael domain, including unpublished data from our laboratory. the viruses of crenarchaeota represent four novel virus families. the fuselloviridae represented by ssvi of s. shibatae and relatives in other sulfolobus strains have th ... | 1996 | 8639330 |
| novel bacterial rhodopsins from haloarcula vallismortis. | new bacterial rhodopsins of the cruxrhodopsin (cr) tribe were identified in a type strain haloarcula vallismortis. the genes encoding a bacteriorhodopsin-like ion pump (named cr-3), a halorhodopsin-like ion pump (chr-3) and a sensor rhodopsin (csr-3) were cloned and sequenced. together with the data for vsrii (seidel et al., proc. natl. acad. sci. usa 92, 3036-3040 (1995); cpr-3 in our notation), the primary structures of a set of four rhodopsins are now all known only in this species. they are ... | 1996 | 8645307 |
| sensitivity of selected members of the family halobacteriaceae to quinolone antimicrobial compounds. | many members of the halobacteriaceae are inhibited by quinolone compounds, which inhibit type ii dna topoisomerase. ciprofloxacin was the most potent inhibitor, followed by ofloxacin and norfloxacin. ciprofloxacin concentration between 25 and 60 micrograms/ml caused 50% inhibition of the growth of most haloferax and haloarcula species. halobacterium species were less sensitive, at sublethal concentrations, formation of elongated and/or swollen cells was observed in many species. the alkaliphilic ... | 1996 | 8661928 |
| analysis of six protein structures predicted by comparative modeling techniques. | the protein structures of six comparative modeling targets were predicted in a procedure that relied on improved energy minimization, without empirical rules, to position all new atoms. the structures of human nucleoside diphosphate kinase nm23-h2, hpr from mycoplasma capricolum, 2fe-2s ferredoxin from haloarcula marismortui, eosinophil-derived neurotoxin (edn), mouse cellular retinoic acid protein i (crabp1), and p450eryf were predicted with root mean square deviations on c alpha atoms of 0.69, ... | 1995 | 8749843 |
| conserved sequence elements involved in regulation of ribosomal protein gene expression in halophilic archaea. | a region of the haloferax volcanii genome encoding ribosomal proteins l11e, l1e, l10e, and l12e was cloned and sequenced, and the transcripts derived from the cluster were characterized. flanking and noncoding regions of the sequence were analyzed phylogenetically by comparison with the homologous sequences from two other halophilic archaea, i.e., halobacterium cutirubrum and haloarcula marismortui. motifs, identified by high-level sequence conservation, include both transcriptional and translat ... | 1996 | 8755911 |
| phylogenetic analyses of some extremely halophilic archaea isolated from dead sea water, determined on the basis of their 16s rrna sequences. | twenty-two extremely halophilic aerobic archaeal strains were isolated from enrichments prepared from dead sea water samples collected 57 years ago. the isolates were phenotypically clustered into five different groups, and a representative from each group was chosen for further study. almost the entire sequences of the 16s rrna genes of these representatives, and of haloarcula hispanica atcc 33960, were determined to establish their phylogenetic positions. the sequences of these strains were co ... | 1996 | 8837434 |
| structure and heterologous expression of the gene encoding the cell surface glycoprotein from haloarcula japonica strain tr-1. | the gene encoding the cell surface glycoprotein (csg) of haloarcula japonica strain tr-1 was cloned and sequenced. the structural gene consisted from an open reading frame of 2,586 bp. a potential promoter sequence was found about 150 bp upstream of the atg initiation codon. n-terminal amino acid sequence of the ha. japonica csg revealed that the mature csg consisted of 828 amino acids. five potential n-glycosylation sites were found in the mature sequence. the cloned csg gene of ha. japonica wa ... | 1995 | 8841572 |
| haloarcula argentinensis sp. nov. and haloarcula mukohataei sp. nov., two new extremely halophilic archaea collected in argentina. | strains arg-1t (t = type strain) and arg-2t, two new strains of extremely halophilic archaea, were isolated from the soils of the argentine salt flats. the taxonomic features of arg-1t were similar to, but distinct from, those of the type strain of haloarcula vallismortis and other haloarcula species. on the 16s rrna phylogenetic tree, strain arg-1t formed a cluster together with haloarcula species. strain arg-2t differed in its glycolipid composition but still was more closely related to the ge ... | 1997 | 8995805 |
| biochemical and serological evidence for an rnase e-like activity in halophilic archaea. | endoribonuclease rnase e appears to control the rate-limiting step that mediates the degradation of many mrna species in bacteria. in this work, an rnase e-like activity in archaea is described. an endoribonucleolytic activity from the extreme halophile haloarcula marismortui showed the same rna substrate specificity as the escherichia coli rnase e and cross-reacted with a monoclonal antibody raised against e. coli rnase e. the archaeal rnase e activity was partially purified from the extreme ha ... | 1997 | 9023200 |
| seryl-trna synthetase from the extreme halophile haloarcula marismortui--isolation, characterization and sequencing of the gene and its expression in escherichia coli. | the seryl-trna synthetase from the extreme halophilic archaebacterium haloarcula marismortui, belonging to the group euryarchaeota, has been purified and its hyperhalophilic behavior demonstrated by activity and stability tests in kcl, nacl and mgcl2 solutions. although the natural external environment of this archaebacterium is rich in sodium ions and poor in potassium ions, the converse being the case in the bacterial cytosol. there is no large significant difference in activity and stability ... | 1997 | 9030733 |
| properties and primary structure of a thermostable l-malate dehydrogenase from archaeoglobus fulgidus. | a thermostable l-malate dehydrogenase from the hyperthermophilic sulfate-reducing archaeon archaeoglobus fulgidus was isolated and characterized, and its gene was cloned and sequenced. the enzyme is a homodimer with a molecular mass of 70 kda and catalyzes preferentially the reduction of oxaloacetic acid with nadh. a. fulgidus l-malate dehydrogenase was stable for 5 h at 90 degrees c, and the half-life at 101 degrees c was 80 min. thus, a. fulgidus l-malate dehydrogenase is the most thermostable ... | 1997 | 9211715 |
| stabilisation of halophilic malate dehydrogenase from haloarcula marismortui by divalent cations -- effects of temperature, water isotope, cofactor and ph. | halophilic malate dehydrogenase is stable in a limited concentration range of mgcl2 or cacl2. thermal deactivation of the protein at low concentrations of these divalent salts is very different from that occurring at high concentrations. in low salt, stability always increases as the temperature is lowered. in high salt, stability shows bell-shaped behaviour as a function of temperature: increasing to a maximum at 4 degrees c, and subsequently decreasing as the temperature is lowered. this is in ... | 1997 | 9370373 |
| functional implications of ribosomal protein l2 in protein biosynthesis as shown by in vivo replacement studies. | the translational apparatus is a highly complex structure containing three to four rna molecules and more than 50 different proteins. in recent years considerable evidence has accumulated to indicate that the rna participates intensively in the catalysis of peptide-bond formation, whereas a direct involvement of the ribosomal proteins has yet to be demonstrated. here we report the functional and structural conservation of a peptidyltransferase centre protein in all three phylogenetic domains. in ... | 1998 | 9531480 |
| molecular cloning of the gene encoding a 2fe-2s ferredoxin from extremely halophilic archaeon haloarcula japonica strain tr-1. | a ferredoxin was purified from extremely halophilic archaeon haloarcula japonica strain tr-1, and then characterized. the ha. japonica ferredoxin proved to contain a 2fe-2s cluster. a part of the gene encoding the ferredoxin was amplified by pcr. subsequently, the entire ferredoxin gene was cloned from chromosomal dna of ha. japonica using the pcr product as a probe. the structural gene consisted of an open reading frame of 387 nucleotides. the deduced amino acid sequence showed 89-98% identitie ... | 1997 | 9586023 |
| primary structure of the novel bacterial rhodopsin from extremely halophilic archaeon haloarcula japonica strain tr-1. | a novel bacterial rhodopsin was identified in haloarcula japonica strain tr-1. the gene encoding the bacterial rhodopsin was cloned and sequenced. the structural gene consisted of an open reading frame of 750 nucleotides encoding 250 amino acids. the deduced amino acid sequence of the ha. japonica bacterial rhodopsin showed the highest homology to those of cruxrhodopsins. | 1997 | 9586024 |
| a 9 a resolution x-ray crystallographic map of the large ribosomal subunit. | the 50s subunit of the ribosome catalyzes the peptidyl-transferase reaction of protein synthesis. we have generated x-ray crystallographic electron density maps of the large ribosomal subunit from haloarcula marismortui at various resolutions up to 9 a using data from crystals that diffract to 3 a. positioning a 20 a resolution em image of these particles in the crystal lattice produced phases accurate enough to locate the bound heavy atoms in three derivatives using difference fourier maps, thu ... | 1998 | 9657144 |
| electrostatic contributions to the stability of halophilic proteins. | examination of the first crystal structures of proteins from a halophilic organism suggests that an abundance of acidic residues distributed over the protein surface is a key determinant of adaptation to high-salt conditions. although one extant theory suggests that acidic residues are favored because of their superior water-binding capacity, it is clear that extensive repulsive electrostatic interactions will also be present in such proteins at physiological ph. to investigate the magnitude and ... | 1998 | 9677300 |
| cloning and sequencing of the gene encoding the cell surface glycoprotein of haloarcula japonica strain tr-1. | the triangular disk-shaped halophilic archaeon haloarcula japonica strain tr-1 has a glycoprotein on its cell surface. the complete gene encoding the cell surface glycoprotein (csg) was cloned and sequenced. the gene has an open reading frame of 2586 bp, and a potential archaeal promoter sequence approximately 150 bp upstream of the atg initiation codon. the mature csg is composed of 828 amino acids and is preceded by a signal sequence of 34 amino acid residues. a hydropathy analysis showed a hy ... | 1997 | 9680334 |
| transcription analysis of two disparate rrna operons in the halophilic archaeon haloarcula marismortui. | the genome of the halophilic archaeon haloarcula marismortui contains two rrna operons designated rrna and rrnb. genomic clones of the two operons and their flanking regions have been sequenced, and primary transcripts and processing intermediates derived from each operon have been characterized. the 16s, 23s, and 5s genes from the two operons were found to differ at 74 of 1,472 positions, 39 of 2,922 positions, and 2 of 122 positions, respectively. this degree of sequence divergence for multico ... | 1998 | 9733681 |
| his1, an archaeal virus of the fuselloviridae family that infects haloarcula hispanica. | a novel archaeal virus, his1, was isolated from hypersaline waters in southeastern australia. it was lytic, grew only on haloarcula hispanica (titers of up to 10(11) pfu/ml), and displayed a lemon-shaped morphology (74 by 44 nm) previously reported only for a virus of the extreme thermophiles (ssv1). the density of his1 was approximately 1.28 g/ml, similar to that of ssv1 (1.24 g/ml). purified particles were resistant to low salt concentrations. the genome was linear, double-stranded dna of 14.9 ... | 1998 | 9765495 |
| halobacterial a-atp synthase in relation to v-atpase. | the head piece separated from the a-atp synthase of halobacterium halobium hydrolyses atp. this a1-atpase is inhibited by nitrate but not by other chaotropic anions. the nitrate inhibition is noncompetitive with respect to atp, reversible, and partially protected by chloride. in contrast, atp synthase in situ (a1ao-atpase) is not inhibited by nitrate but apparently is inhibited by stronger chaotropic reagents, such as thiocyanate and trichloroacetate, which make the vesicle membrane permeable to ... | 1992 | 9874757 |
| the protein sequence of an archaeal catalase-peroxidase. | the gene encoding a catalase-peroxidase of archaeal origin, the halophilic catalase-peroxidase from haloarcula marismortui, was sequenced. the primary structure proposed was confirmed by edman degradation and mass spectrometry analyses of proteolytic fragments of the purified protein. the open reading frame in the gene corresponds to 731 amino acids and the calculated mass of the mature protein (deleted of the n-terminal methionine) is 81,253.65 da, in reasonable agreement with the value of 81,2 ... | 1998 | 9924978 |
| archaeabacterial seryl-trna synthetases: adaptation to extreme environments and evolutionary analysis. | the aminoacyl-trna synthetases are ubiquitous enzymes which catalyze a crucial step of the cell life, the specific attachment of amino acids to their cognate trna. the amino acid sequences of three archaeal seryl-trna synthetases (serrs) from haloarcula marismortui and methanococcus jannaschii, both belonging to the group of euryarchaeota, and from sulfolobus solfataricus, of the group of crenarchaeota, were aligned with other eubacterial and eukaryal available serrs sequences. in an attempt to ... | 1999 | 10079279 |
| role of the 37 kda laminin receptor precursor in the life cycle of prions. | prions are thought to consist of infectious proteins that cause, in the absence of detectable nucleic acid, a group of fatal neurodegenerative diseases, called transmissible spongiform encephalopathies (tse). among these diseases are bovine spongiform encephalopathy (bse), scrapie of sheep and creutzfeldt-jakob disease (cjd) in humans. they occur as sporadic, infectious or genetic disorders and have in common the accumulation of an abnormal, pathogenic isoform of the cellular prion protein prpc ... | 1999 | 10188208 |
| amino acid biosynthesis in the halophilic archaeon haloarcula hispanica. | biosynthesis of proteinogenic amino acids in the extremely halophilic archaeon haloarcula hispanica was explored by using biosynthetically directed fractional 13c labeling with a mixture of 90% unlabeled and 10% uniformly 13c-labeled glycerol. the resulting 13c-labeling patterns in the amino acids were analyzed by two-dimensional 13c,1h correlation spectroscopy. the experimental data provided evidence for a split pathway for isoleucine biosynthesis, with 56% of the total ile originating from thr ... | 1999 | 10322026 |
| structural studies of the translational apparatus. | significant progress is occurring at an accelerated rate in structural studies of ribosomes. a 3d cryoelectron microscopy map of the 70s ribosome from escherichia coli is available at 15 a resolution and a combination of cryoelectron microscopy with x-ray crystallography has yielded a 9 a resolution map of the 50s subunit from haloarcula marismortui, an archaebacterium. for eukaryotes, 3d cryomaps of the 80s ribosomes from yeast and from mammals have now been produced at resolutions in the range ... | 1999 | 10322215 |
| bioenergetic aspects of halophilism. | examination of microbial diversity in environments of increasing salt concentrations indicates that certain types of dissimilatory metabolism do not occur at the highest salinities. examples are methanogenesis for h2 + co2 or from acetate, dissimilatory sulfate reduction with oxidation of acetate, and autotrophic nitrification. occurrence of the different metabolic types is correlated with the free-energy change associated with the dissimilatory reactions. life at high salt concentrations is ene ... | 1999 | 10357854 |
| relative role of anions and cations in the stabilization of halophilic malate dehydrogenase. | halophilic malate dehydrogenase unfolds at low salt, and increasing the salt concentration stabilizes, first, the folded form and then, in some cases, destabilizes it. from inactivation and fluorescence measurements performed on the protein after its incubation in the presence of various salts in a large range of concentrations, the apparent effects of anions and cations were found to superimpose. a large range of ions was examined, including conditions that are in general not of physiological r ... | 1999 | 10413477 |
| haloarcula quadrata sp. nov., a square, motile archaeon isolated from a brine pool in sinai (egypt). | the motile, predominantly square-shaped, red archaeon strain 801030/1t, isolated from a brine pool in the sinai peninsula (egypt), was characterized taxonomically. on the basis of its polar lipid composition, the nucleotide sequences of its two 16s rrna genes, the dna g+c content (60.1 mol%) and its growth characteristics, the isolate could be assigned to the genus haloarcula. however, phylogenetic analysis of the two 16s rrna genes detected in this organism and low dna-dna hybridization values ... | 1999 | 10425773 |
| elucidating the medium-resolution structure of ribosomal particles: an interplay between electron cryo-microscopy and x-ray crystallograhy. | ribosomes are the universal cellular organelles that accomplish the translation of the genetic code into proteins. electron cryo-microscopy (cryo-em) has yielded fairly detailed three-dimensional reconstructions of ribosomes. these were used to assist in the determination of higher resolution structures by x-ray crystallography. | 1999 | 10467138 |
| mechanics of the ribosome. | | 1999 | 10476952 |
| placement of protein and rna structures into a 5 a-resolution map of the 50s ribosomal subunit. | we have calculated at 5.0 a resolution an electron-density map of the large 50s ribosomal subunit from the bacterium haloarcula marismortui by using phases derived from four heavy-atom derivatives, intercrystal density averaging and density-modification procedures. more than 300 base pairs of a-form rna duplex have been fitted into this map, as have regions of non-a-form duplex, single-stranded segments and tetraloops. the long rods of rna crisscrossing the subunit arise from the stacking of sho ... | 1999 | 10476961 |
| ribosome finally begins to yield its complete structure. | | 1999 | 10490407 |
| metal compounds as tools for the construction and the interpretation of medium-resolution maps of ribosomal particles. | procedures were developed exploiting organometallic clusters and coordination compounds in combination with heavy metal salts for derivatization of ribosomal crystals. these enabled the construction of multiple isomorphous replacement (mir) and multiple isomorphous replacement combined with anomalous scattering medium-resolution electron density maps for the ribosomal particles that yield the crystals diffracting to the highest resolution, 3 a, of the large subunit from haloarcula marismortui an ... | 1999 | 10527903 |
| cashing in on crystals. | structures of the ribosome and its two subunits have been determined by x-ray crystallography at resolutions sufficient to reveal interactions between rna and protein in the subunits and orientations of substrates at the subunit interface in the intact ribosome. | 1999 | 10530999 |
| an improved transposon for the halophilic archaeon haloarcula hispanica. | an improved transposon (thd73) for haloarcula hispanica is described. based on the halobacterial insertion sequence ish28, it showed little target sequence specificity but was biased toward a lower g+c content. twenty randomly selected thd73 mutants were analyzed, and the dna flanking their insertions revealed several recognizable sequences, including two (unrelated) ish elements. | 1999 | 10559183 |
| haloarcula marismortui 50s subunit-complementarity of electron microscopy and x-ray crystallographic information. | the large 50s subunit of the haloarcula marismortui 70s ribosome was solved to 19 a using cryo-electron microscopy and single particle reconstruction techniques and to 9 a using x-ray crystallography. in the latter case, phases were determined by multiple isomorphous replacement and anomalous scattering from three heavy atom derivatives. the availability of x-ray and electron microscopy (em) data has made it possible to compare the results of the two experimental methods. in the flexible regions ... | 1999 | 10600557 |
| halophilic adaptation: novel solvent protein interactions observed in the 2.9 and 2.6 a resolution structures of the wild type and a mutant of malate dehydrogenase from haloarcula marismortui. | previous biophysical studies of tetrameric malate dehydrogenase from the halophilic archaeon haloarcula marismortui (hm maldh) have revealed the importance of protein-solvent interactions for its adaptation to molar salt conditions that strongly affect protein solubility, stability, and activity, in general. the structures of the e267r stability mutant of apo (-nadh) hm maldh determined to 2.6 a resolution and of apo (-nadh) wild type hm maldh determined to 2.9 a resolution, presented here, high ... | 2000 | 10653643 |
| insights into the molecular relationships between malate and lactate dehydrogenases: structural and biochemical properties of monomeric and dimeric intermediates of a mutant of tetrameric l-[ldh-like] malate dehydrogenase from the halophilic archaeon haloarcula marismortui. | l-malate (maldh) and l-lactate (ldh) dehydrogenases belong to the same family of nad-dependent enzymes. ldhs are tetramers, whereas maldhs can be either dimeric or tetrameric. to gain insight into molecular relationships between ldhs and maldhs, we studied folding intermediates of a mutant of the ldh-like maldh (a protein with ldh-like structure and maldh enzymatic activity) from the halophilic archaeon haloarcula marismortui (hm maldh). crystallographic analysis of hm maldh had shown a tetramer ... | 2000 | 10653644 |
| mapping posttranscriptional modifications in 5s ribosomal rna by maldi mass spectrometry. | we present a method to screen rna for posttranscriptional modifications based on matrix assisted laser desorption/ionization mass spectrometry (maldi-ms). after the rna is digested to completion with a nucleotide-specific rnase, the fragments are analyzed by mass spectrometry. a comparison of the observed mass data with the data predicted from the gene sequence identifies fragments harboring modified nucleotides. fragments larger than dinucleotides were valuable for the identification of posttra ... | 2000 | 10688367 |
| purification and characterization of dissimilatory nitrate reductase from a denitrifying halophilic archaeon, haloarcula marismortui. | dissimilatory nitrate reductase was purified from a denitrifying halophilic archaeon, haloarcula marismortui, to an electrophoretically homogeneous state. the purified enzyme was inferred to be a homotetramer composed of a 63 kda polypeptide. the electron paramagnetic resonance spectrum of the purified enzyme revealed typical rhombic signals which were ascribed to mo(v) in the mo-molybdopterin complex. like the bacterial membrane-bound (nar-) enzyme, the purified enzyme supported the catalysis o ... | 2000 | 10734237 |
| expression, purification, crystallization and preliminary x-ray diffraction studies of bacterial and archaeal l4 ribosomal proteins. | ribosomal protein l4 is implicated in the peptidyltransferase activity of the ribosome and in certain bacteria it regulates the transcription and translation of the 11-gene s10 operon. the genes for the l4 ribosomal proteins from the hyperthermophilic bacterium thermotoga maritima and the halophilic archaeon haloarcula marismortui have been pcr amplified from genomic dna and cloned under the control of a t7 promoter to generate overexpressing escherichia coli strains. for both proteins, efficien ... | 2000 | 10771437 |
| transcriptional regulation of cruxrhodopsin gene from extremely halophilic archaeon haloarcula japonica strain tr-1. | transcription of the cruxrhodopsin (cr) gene in extremely halophilic archaeon haloarcula japonica strain tr-1 was investigated using northern analysis to quantify message level. in the cell cultures growing in the dark, cr transcript level remained very low. in contrast, exposure of the cell cultures to light stimulated transcription of the cr gene. in addition, cr gene transcription was also induced when ha. japonica was grown under high oxygen tension and then shifted to low oxygen tension in ... | 1999 | 10780385 |
| molecular cloning of a1-atpase gene from extremely halophilic archaeon haloarcula japonica strain tr-1. | the genes encoding a1-atpase a- and b-subunits were cloned from haloarcula japonica strain tr-1. nucleotide sequencing analysis of the a1-atpase gene revealed that the a- and b-subunits consisted of 586 and 473 amino acids, respectively. the deduced amino acid sequences of the a- and b-subunits of ha. japonica showed high identities with those of halobacterium salinarum and haloferax volcanii. the consensus atp-binding motif was found in the a-subunit. | 1999 | 10780386 |
| a novel bacteriorhodopsin-like protein from haloarcula japonica strain tr-1: gene cloning, sequencing, and transcript analysis. | the gene encoding a novel bacteriorhodopsin (br)-like protein from haloarcula japonica strain tr-1 was cloned and sequenced. the nucleotide sequence of the gene contained an open reading frame that corresponded to a protein of 250 amino acids. the deduced amino acid sequence of ha. japonica br-like protein exhibited the highest homology to those of cruxrhodopsins (crs) produced by members of the genus haloarcula, suggesting that the br-like protein of ha. japonica belonged to the cr subfamily. t ... | 2000 | 10805565 |
| purification and characterization of a ferredoxin from haloarcula japonica strain tr-1. | a ferredoxin (fd) was purified from the extremely halophilic archaeon, haloarcula japonica strain tr-1, to electrophoretic homogeneity. the apparent molecular weight (mr) of the fd was estimated to be 24,000 on sds-polyacrylamide gel electrophoresis. the amino acid composition analysis revealed that the fd composed of a number of acidic amino acids (uncorrected for amides). the n-terminal amino acid sequence (30 residues) was determined to be: ptveylnyevvddngwdmydddvfaeasdm. the iron content was ... | 2000 | 10831221 |
| bioreaction network topology and metabolic flux ratio analysis by biosynthetic fractional 13c labeling and two-dimensional nmr spectroscopy. | biosynthetically directed fractional 13c labeling of the proteinogenic amino acids is achieved by feeding a mixture of uniformly 13c-labeled and unlabeled carbon source compounds into a bioreaction network. analysis of the resulting labeling pattern enables both a comprehensive characterization of the network topology and the determination of metabolic flux ratios. attractive features with regard to routine applications are (i) an inherently small demand for 13c-labeled source compounds and (ii) ... | 1999 | 10937933 |
| the complete atomic structure of the large ribosomal subunit at 2.4 a resolution. | the large ribosomal subunit catalyzes peptide bond formation and binds initiation, termination, and elongation factors. we have determined the crystal structure of the large ribosomal subunit from haloarcula marismortui at 2.4 angstrom resolution, and it includes 2833 of the subunit's 3045 nucleotides and 27 of its 31 proteins. the domains of its rnas all have irregular shapes and fit together in the ribosome like the pieces of a three-dimensional jigsaw puzzle to form a large, monolithic struct ... | 2000 | 10937989 |
| the structural basis of ribosome activity in peptide bond synthesis. | using the atomic structures of the large ribosomal subunit from haloarcula marismortui and its complexes with two substrate analogs, we establish that the ribosome is a ribozyme and address the catalytic properties of its all-rna active site. both substrate analogs are contacted exclusively by conserved ribosomal rna (rrna) residues from domain v of 23s rrna; there are no protein side-chain atoms closer than about 18 angstroms to the peptide bond being synthesized. the mechanism of peptide bond ... | 2000 | 10937990 |
| structural biology. the ribosome is a ribozyme. | ribosomes, the cellular factories that manufacture proteins, contain both rna and protein, but exactly how all of the different ribosomal components contribute to protein synthesis is still not clear. now, as thomas cech explains in his perspective, atomic resolution of the structure of the large ribosomal subunit reveals that, as predicted by those convinced of a prebiotic rna world, rna is the catalytic component with proteins being the structural units that support and stabilize it (ban et al ... | 2000 | 10960319 |