| ferric iron reduction by sulfur- and iron-oxidizing bacteria. | acidophilic bacteria of the genera thiobacillus and sulfolobus are able to reduce ferric iron when growing on elemental sulfur as an energy source. it has been previously thought that ferric iron serves as a nonbiological oxidant in the formation of acid mine drainage and in the leaching of ores, but these results suggest that bacterial catalysis may play a significant role in the reactivity of ferric iron. | 1976 | 825043 |
| structural features of archaebacterial cell envelopes. | regularly arrayed surface (glyco) proteins--often referred to as s layers--are a common feature of the cell envelopes of almost all archaebacteria. we have selected some examples (halobacterium, sulfolobus, thermoproteus, pyrobaculum, staphylothermus), and we describe the structure of their surface layers as revealed primarily by electron crystallography. in spite of a considerable diversity in shapes and dimensions, some common structural features emerge from the comparison. the glycoprotein ar ... | 1992 | 1459988 |
| expression of a hyperthermophilic aspartate aminotransferase in escherichia coli. | the gene for an archaebacterial hyperthermophilic enzyme, aspartate aminotransferase from sulfolobus solfataricus (aspatss), was expressed in escherichia coli and the enzyme purified to homogeneity. a suitable expression vector and host strain were selected and culture conditions were optimized so that 6-7 mg of pure enzyme per litre of culture were obtained repeatedly. the recombinant enzyme and the authentic aspatss are indistinguishable: in fact, they have the same molecular weight, estimated ... | 1992 | 1445947 |
| thermoacidophilic archaebacteria: potential applications. | | 1992 | 1445405 |
| production of an antiserum specific to the adp-ribosylated form of elongation factor 2 from archaebacteria and eukaryotes. | an antiserum to adp-ribosylated elongation factor 2 (adpr-ef-2) from s. acidocaldarius was raised in rabbits using stained, homogenized, adpr-ef-2-containing slices from sds-gels as a source of antigen. elongation factor 2 (ef-2) from s. acidocaldarius was cloned in e. coli and the expressed gene product was used in order to adsorb all anti-ef-2 antibodies which do not contain the adp-ribosyl group within their epitopes, as e. coli is unable to synthesize the adp-ribosyl acceptor diphthamide. th ... | 1992 | 1426243 |
| direct observation of defect structure in protein crystals by atomic force and transmission electron microscopy. | we have examined the structure of s-layers isolated from sulfolobus acidocaldarius using atomic force microscopy (afm) and transmission electron microscopy (tem). from the afm images, we were able to directly observe individual dimers of the crystal, defects in the crystal structure, and twin boundaries. we have identified two types of boundaries, one defined by a mirror plane and the other by a glide plane. this work shows that twin boundaries are highly structured regions that are directly rel ... | 1992 | 1420904 |
| black lipid membranes of tetraether lipids from thermoplasma acidophilum. | black lipid membranes were formed of tetraether lipids from thermoplasma acidophilum and compared to the bilayer forming lipids diphytanoylphosphatidylcholine and diphythanylglucosylglycerol. bilayer-forming lipids varied in thickness of black lipid membranes due to the organic solvent used. measurements of the specific membrane capacitance (cm = 0.744 microf/cm2) showed that the membrane-spanning tetraether lipids from thermoplasma acidophilum form a monolayer of a constant thickness of 2.5-3.0 ... | 1992 | 1420295 |
| molecular, functional and structural properties of an archaebacterial elongation factor 2. | the elongation factor 2 (aef-2) from the extreme thermo-acidophilic archaebacterium sulfolobus solfataricus, is the only cytosolic target protein which is adp-ribosylated by diphtheria toxin in presence of nad. once adp-ribosylated, aef-2 is no longer able to sustain poly(phe) synthesis in vitro. aef-2 displays a great thermoresistance: at the growth temperature of the archaebacterium, 87 degrees c, its half-life is 3 h. the amino acid sequence of the n-terminal region of aef-2 has been determin ... | 1992 | 1390884 |
| f-type or v-type? the chimeric nature of the archaebacterial atp synthase. | archaebacterial plasma membranes contain an atpase acting in vivo as a delta mu h(+)-driven atp synthase. while functional features and their general structural design are resembling f-type atpases, primary sequences of the two large polypeptides from the catalytic part are closely related to v-type atpases from eucaryotic vacuolar membranes. the chimeric nature of archaebacterial atpase from sulfolobus was investigated in terms of nucleotide interactions and related to specific sequence paramet ... | 1992 | 1385979 |
| an archaebacterial terminal oxidase combines core structures of two mitochondrial respiratory complexes. | the operon coding for a respiratory quinol oxidase was cloned from thermoacidophilic archaebacterium sulfolobus acidocaldarius. it contains three genes, soxa, soxb and soxc. the first two genes code for proteins related to the cytochrome c oxidase subunits ii and i, respectively. soxc encodes a protein homologous to cytochrome b, which is a subunit of the mitochondrial and bacterial cytochrome c reductases and the chloroplast cytochrome b6f complex. soxa is preceded by a promoter and the genes a ... | 1992 | 1372250 |
| heterologous expression of thermopsin, a heat-stable acid proteinase. | we have previously reported the isolation, characterization, and gene sequence of a new thermostable acid protease, thermopsin, from sulfolobus acidocaldarius, a thermophilic archaebacterium. thermopsin is similar to aspartic protease pepsin in specificity and ph dependence. however, it optimally catalyzes in the temperature range of 85 to 90 degrees c and it is not structurally related to pepsin. the current report describes the synthesis of recombinant thermopsin in e. coli and in insect cells ... | 1992 | 1368892 |
| effect of temperature on the propylamine transferase from sulfolobus solfataricus, an extreme thermophilic archaebacterium. 2. denaturation and structural stability. | the thermal stability of propylamine transferase from sulfolobus solfataricus, an extreme thermophilic archaebacterium, has been characterized thermodynamically by a van't hoff analysis. conformational transitions induced by guanidine hydrochloride, as well as by temperature, have been linked together in a scheme involving six equilibria, which arise from both dissociation and unfolding. the mechanism by which the protein achieves thermal stabilization is quite unusual. it is driven by a conform ... | 1992 | 1541264 |
| the glna gene of the extremely thermophilic eubacterium thermotoga maritima: cloning, primary structure, and expression in escherichia coli. | the structural gene (glna) encoding the glutamine synthetase (gs) of the extremely thermophilic eubacterium thermotoga maritima has been cloned on a 6.0 kb hindiii dna fragment. sequencing of the region containing the glna gene (1444 bp) showed an orf encoding a polypeptide (439 residues) with an estimated mass of 50,088 da, which shared significant homology with the gsi sequences of other bacteria (escherichia coli, bacillus subtilis) and archaea (pyrococcus woesei, sulfolobus solfataricus). th ... | 1992 | 1348781 |
| epr studies of cytochrome aa3 from sulfolobus acidocaldarius. evidence for a binuclear center in archaebacterial terminal oxidase. | the purified cytochrome aa3-type oxidase from sulfolobus acidocaldarius (dsm 639) consists of a single subunit, containing one low-spin and one high-spin a-type hemes and copper [anemüller, s. and schäfer, g. (1990) eur. j. biochem. 191, 297-305]. the enzyme metal centers were investigated by electron paramagnetic resonance spectroscopy (epr), coupled to redox potentiometry. the low-spin heme epr signal has the following g-values: gz = 3.02, gy = 2.23 and gx = 1.45 and the high-spin heme exhibit ... | 1992 | 1332857 |
| energy transduction in the methanogen methanococcus voltae is based on a sodium current. | we provide experimental support for the proposal that atp production in methanococcus voltae, a methanogenic member of the archaea, is based on an energetic system in which sodium ions, not protons, are the coupling ions. we show that when grown at a ph of 6.0, 7.1, or 8.2, m. voltae cells maintain a membrane potential of approximately -150 mv. the cells maintain a transmembrane ph gradient (ph(in) - ph(out)) of -0.1, -0.2, and -0.2, respectively, values not favorable to the inward movement of p ... | 1992 | 1324904 |
| characterization and purification of a membrane-bound archaebacterial pyrophosphatase from sulfolobus acidocaldarius. | plasma membranes of the thermoacidophilic archaebacterium sulfolobus acidocaldarius (dsm 639) display a pyrophosphate-hydrolyzing activity [m. lübben & g. schäfer (1987) eur. j. biochem. 164, 533-540]. in our present work, we solubilized and purified this pyrophosphatase to homogeneity. it consists of a single subunit with a molecular mass of 17-18 kda, forming an oligomer of 70 kda under native conditions. edman degradation revealed 30 amino acids of the n-terminus. the enzyme cleaves phosphori ... | 1992 | 1321720 |
| 5-(p-aminophenyl)-1,2,3,4-tetrahydroxypentane, a structural component of the modified folate in sulfolobus solfataricus. | the partial characterization of the modified folate present in sulfolobus solfataricus has been carried out. separation of ethanol-water extracts of these cells on a deae-sephadex column led to the isolation of a small amount of intact oxidized cofactor, which, when subjected to reductive cleavage with zn-hcl, produced 6-methylpterin. this indicated that the modified folate in these cells contained a nonmethylated pterin linked, via a methylene group at the c-6 position of the pterin, to an aryl ... | 1992 | 1320614 |
| an extremely stable inorganic pyrophosphatase purified from the cytosol of a thermoacidophilic archaebacterium, sulfolobus acidocaldarius strain 7. | a highly active inorganic pyrophosphatase was purified to electrophoretical homogeneity from the cytosol of sulfolobus acidocaldarius strain 7, an extremely thermoacidophilic archaebacterium. the enzyme has an apparent molecular mass of 80 kda as estimated by gel permeation chromatography, and showed a 21-kda polypeptide on sds-page, suggesting that the archaebacterial enzyme is similar to most of the eubacterial pyrophosphatases rather than eukaryotic ones. the pi = 5.1. the enzyme showed relat ... | 1992 | 1315573 |
| functional reconstitution of membrane proteins in monolayer liposomes from bipolar lipids of sulfolobus acidocaldarius. | membranes of sulfolobus acidocaldarius, an extreme thermophilic archaebacterium, are composed of unusual bipolar lipids. they consist of macrocyclic tetraethers with two polar heads linked by two hydrophobic c40 phytanyl chains which are thought to be arranged as a monolayer in the cytoplasmic membrane. fractionation of a total lipid-extract from s. acidocaldarius yielded a lipid fraction which forms closed and stable unilamellar liposomes in aqueous media. beef heart cytochrome c-oxidase could ... | 1992 | 1309769 |
| the plasma membrane atpase of archaebacteria. a chimeric energy converter. | | 1992 | 1288326 |
| elements of an archaeal promoter defined by mutational analysis. | the sequence requirements for specific and efficient transcription from the 16s/23s rrna promoter of sulfolobus shibatae were analysed by point mutations and by cassette mutations using an in vitro transcription system. the examination of the box a-containing distal promoter element (dpe) showed the great importance of the ta sequence in the center of box a for transcription efficiency and the influence of the sequence upstream of box a on determining the distance between the dpe and the start s ... | 1992 | 1279520 |
| comparative lipid composition of heterotrophically and autotrophically grown sulfolobus acidocaldarius. | complex lipids from the thermoacidophilic facultative autotroph sulfolobus acidocaldarius, as well as a strictly autotrophic isolate, were compared between cells grown on yeast extract and elemental sulfur. lipids from both organisms grown autotrophically were nearly identical. each contained about 15% neutral lipids, 35% glycolipids, and 50% acidic lipids. glycolipids and acidic lipids contained c40h82-76-derived glycerol ether residues. major glycolipids included the glycerol ether analogues o ... | 1977 | 863856 |
| diphytanyl and dibiphytanyl glycerol ether lipids of methanogenic archaebacteria. | the lipids of nine different methanogenic bacterial strains are comprised of diphytanyl glycerol diethers, previously known only in extremely halophilic bacterial, as well as dibiphytanyl diglycerol tetraethers, known formerly only in the extremely thermoacidophilic bacteria thermoplasma and sulfolobus. of the methanogens examined from four representative taxonomic groups, methanobacterium and methanospirillum contained both types of isopranyl ethers in nearly equal proportions, whereas the cocc ... | 1979 | 758677 |
| squalenes, phytanes and other isoprenoids as major neutral lipids of methanogenic and thermoacidophilic "archaebacteria". | the neutral lipids of nine species of methanogenic bacteria including five methanobacilli, two methanococci, a methanospirillum, one methanosarcina as well as two thermoacidophilic bacteria, thermoplasma and sulfolobus, were analyzed. the major components were c30, c25 and/or c20 acylic isoprenoid hydrocarbons with a continuous range of hydroisoprenoid homologues. the range of acyclic isoprenoids detected were from c14 to c30. apart from methanosarcina barkeri, squalene and/or hydrosqualene deri ... | 1979 | 458874 |
| dna-dependent rna polymerase from the archaebacterium sulfolobus acidocaldarius. | purified dna-dependent rna polymerase from sulfolobus acidocaldarius is composed of 10 different subunits, one of which is present as four copies. their molecular weights are 122 000, 101 000, 44 000, 32 000, 24 000, 17 500, 13 800, 11 800 (four copies), 11 200, 10 800, summing up to a total mr of 423 500. the sedimentation velocity is 13.5 s, indicating that at 0.5 m nh4cl the enzyme exists in the monomeric form. at ph 9.2 in cellogel electrophoresis two of the subunits migrate towards the cath ... | 1979 | 380989 |
| extremely thermophilic acidophilic bacteria convergent with sulfolobus acidocaldarius. | a series of extremely thermophilic acidophilic bacteria has been characterized as closely resembling the species sulfolobus acidocaldarius except for a totally different guanosine-cytosine content in the dna; some conceptual consequences of this situation are discussed. both organisms also share special features, including a very characteristic type of ether lipid, with other extreme acidophilic thermophiles. | 1975 | 234504 |
| thermothrix thioparus gen. et sp. nov. a facultatively anaerobic facultative chemolithotroph living at neutral ph and high temperature. | thermothrix thioparus gen. et ep. nov. occurs naturally in a new mexico hot spring at a temperature of 74 degrees c, a ph of 7.0, and a hs- concentration of 1 mg/litre. the organism is gram-negative, non-motile, 0.5-1.0 x 3-20 mum, and forms cell chains up to 1 cm in length. the resulting filaments do not possess a sheath. sulfur is deposited extracellularly. the organism was isolated using an autotrophic medium with hs- as the energy source and no3- as the terminal electron acceptor. anaerobica ... | 1976 | 10063 |
| reconstitution of the leucine transport system of lactococcus lactis into liposomes composed of membrane-spanning lipids from sulfolobus acidocaldarius. | the effect of bipolar tetraether lipids, extracted from the thermophilic archaebacterium sulfolobus acidocaldarius, on the branched-chain amino acid transport system of the mesophilic bacterium lactococcus lactis was investigated. liposomes were prepared from mixtures of monolayer lipids and the bilayer lipid phosphatidylcholine (pc), analyzed on their miscibility, and fused with membrane vesicles from l. lactis. freeze-fracture electron microscopy demonstrates that the bipolar lipids in the hyb ... | 1992 | 1463735 |
| thermostable nad(+)-dependent alcohol dehydrogenase from sulfolobus solfataricus: gene and protein sequence determination and relationship to other alcohol dehydrogenases. | the nad(+)-dependent alcohol dehydrogenase (ec 1.1.1.1) from the thermoacidophilic archaebacterium sulfolobus solfataricus, dsm1617 strain (ssadh), has been purified and characterized. its gene has been isolated by screening two s. solfataricus genomic libraries using oligonucleotide probes. the encoding sequence consists of 1041 base pairs, and it shows a high preference for codons ending in t or a. the primary structure, determined by peptide and gene analysis, consists of 347 amino acid resid ... | 1992 | 1463738 |
| determination of the unusual amino acid hypusine at the lower picomole level by derivatization with 4-dimethylaminoazobenzene-4'-sulphonyl chloride and reversed-phase high-performance or medium-pressure liquid chromatography. | hypusine, an unusual amino acid formed by post-translational modification of lysine, is normally determined by specific metabolic labelling followed by measurement of released radioactivity after protein hydrolysis. this paper describes a sensitive non-radioactive method for the determination of hypusine, involving complete protein hydrolysis and precolumn derivatization of the released amino acids with 4-dimethylaminoazobenzene-4'-sulphonyl chloride, followed by reversed-phase high-performance ... | 1992 | 1500466 |
| the particle ssv1 from the extremely thermophilic archaeon sulfolobus is a virus: demonstration of infectivity and of transfection with viral dna. | the lemon-shaped "virus-like" particle ssv1 produced by the thermophilic archaeon sulfolobus shibatae has not previously been observed to infect any host. using a plaque assay suitable for the extreme growth conditions of this archaeon, we have shown infection of sulfolobus solfataricus by ssv1. upon infection, the viral genome was always found integrated into a trna gene of the host chromosome, a situation similar to that in s. shibatae, proving that site-specific integration is involved in est ... | 1992 | 1502176 |
| novel fractionation of proteins using novobiocin as a precipitating agent: application to ribosomal proteins from the archaebacterium sulfolobus acidocaldarius and escherichia coli. | a fractionation method involving precipitation of proteins with novobiocin has been developed to separate ribosomal proteins of the archaebacterium sulfolobus acidocaldarius. four groups of proteins were obtained corresponding to those precipitated with 0.2, 0.5 and 1.0 mg/ml novobiocin and the proteins soluble at 1.0 mg/ml novobiocin. the same procedure was also successful for the fractionation of ribosomal proteins from escherichia coli. two dimensional gel electrophoresis showed that proteins ... | 1992 | 1503560 |
| a heat-stable serine proteinase from the extreme thermophilic archaebacterium sulfolobus solfataricus. | a proteinase was purified to electrophoretic homogeneity from crude extracts of the thermoacidophilic archaebacterium sulfolobus solfataricus. molecular mass values assessed by sds-page and gel filtration were 54 and 118 kda, respectively, which points to a dimeric structure of the molecule. an isoelectric point of 5.6 was also determined. the enzyme behaved as a chymotrypsin-like serine proteinase, as shown by the inhibitory effects exerted by phenylmethanesulfonyl fluoride, 3,4-dichloroisocoum ... | 1992 | 1504089 |
| conversion, by limited proteolysis, of an archaebacterial citrate synthase into essentially a citryl-coa hydrolase. | 1. limited proteolysis of citrate synthase from sulfolobus solfataricus by trypsin reduced the rate of the overall reaction (acetyl-coa + oxaloacetate + h2o----citrate + coash) to 4% but did not affect the hydrolysis of citryl-coa. experimental results indicate that a connecting link between the enzyme's ligase and hydrolase activity becomes impaired specifically on treatment with trypsin. other proteolytic enzymes like chymotrypsin and subtilisin inactivated catalytic functions of citrate synth ... | 1992 | 1521537 |
| purification and properties of an atpase from sulfolobus solfataricus. | a sulfite-activated atpase isolated from sulfolobus solfataricus had a relative molecular mass of 370,000. it was composed of three subunits whose relative molecular masses were 63,000, 48,000, and 24,000. the enzyme was inhibited by the vacuolar atpase inhibitors nitrate and n-ethylmaleimide; 4-chloro-7-nitrobenzofurazan (nbd-cl) was also inhibitory. n-ethylmaleimide was predominately bound to the largest subunit while nbd-cl was bound to both subunits. atpase activity was inhibited by low conc ... | 1992 | 1533499 |
| effect of temperature on the propylamine transferase from sulfolobus solfataricus, an extreme thermophilic archaebacterium. 1. conformational behavior of the oligomeric enzyme in solution. | the effect of temperature on the molecular structure of propylamine transferase from sulfolobus solfataricus has been investigated. sulfolobus solfataricus is an extreme thermophilic archaebacterium with an optimum living condition at 90 degrees c. the enzyme is an oligomeric (trimer) protein of molecular mass 112 kda. the frictional ratio for the native protein suggests an irregularly shaped compact globular structure. the protein matrix is well organized as suggested by far ultraviolet circula ... | 1992 | 1541263 |
| the archaebacterial hypusine-containing protein. structural features suggest common ancestry with eukaryotic translation initiation factor 5a. | the amino acid hypusine is formed by post-translational modification of a lysine residue in eukaryotes and archaebacteria but up to now only the eukaryotic translation initiation factor eif-5a has been known to contain this unique component. we isolated and purified a hypusine-containing protein from the thermophilic archaebacterium sulfolobus acidocaldarius. the mainly cytosolic protein comprised about 0.03% of the post-ribosomal supernatant protein. no other hypusine-containing protein could b ... | 1992 | 1541288 |
| limited proteolysis as a probe of conformational changes in aspartate aminotransferase from sulfolobus solfataricus. | the analysis of conformational transitions using limited proteolysis was carried out on a hyperthermophilic aspartate aminotransferase isolated from the archaebacterium sulfolobus solfataricus, in comparison with pig cytosolic aspartate aminotransferase, a thoroughly studied mesophilic aminotransferase which shares about 15% similarity with the archaebacterial protein. aspartate aminotransferase from s. solfataricus is cleaved at residue 28 by thermolysin and residues 32 and 33 by trypsin; analo ... | 1992 | 1551394 |
| isolation of a thermostable enzyme catalyzing disulfide bond formation from the archaebacterium sulfolobus solfataricus. | a disulfide bond-forming enzyme was purified from the cytosol of the archaebacterium sulfolobus solfataricus, strain mt-4. the enzyme, assayed by its ability to oxidize and reactivate reductively denatured ribonuclease a, had a small molecular size and displayed a high thermostability. the n-terminal amino acid sequence is reported. | 1992 | 1592111 |
| molecular packing parameters of bipolar lipids. | the bipolar lipid fractions extracted from the thermophilic archaeobacterium sulfolobus solfataricus have different chemical structures and geometrical shapes. the conditions which lead to the formation of vesicles were investigated in order to study the self-assembly of these molecules. such conditions are fulfilled when an appropriate mixture of two different molecular species (both bipolar or bipolar and monopolar) is used. according to the theory introduced by israelachvili and co-workers, l ... | 1992 | 1596507 |
| purification and characterization of a thermostable carboxypeptidase from the extreme thermophilic archaebacterium sulfolobus solfataricus. | a carboxypeptidase was purified to electrophoretic homogeneity from the thermoacidophilic archaebacterium sulfolobus solfataricus. molecular masses assessed by sds/page and gel filtration were 42 kda and 170 kda, respectively, which points to a tetrameric structure for the molecule. an isoelectric point of 5.9 was also determined. the enzyme was proven to be a metalloprotease, as shown by the inhibitory effects exerted by edta and o-phenanthroline; furthermore, dialysis against edta led to a com ... | 1992 | 1597179 |
| early evolutionary relationships among known life forms inferred from elongation factor ef-2/ef-g sequences: phylogenetic coherence and structure of the archaeal domain. | phylogenies were inferred from both the gene and the protein sequences of the translational elongation factor termed ef-2 (for archaea and eukarya) and ef-g (for bacteria). all treeing methods used (distance-matrix, maximum likelihood, and parsimony), including evolutionary parsimony, support the archaeal tree and disprove the "eocyte tree" (i.e., the polyphyly and paraphyly of the archaea). distance-matrix trees derived from both the amino acid and the dna sequence alignments (first and second ... | 1992 | 1602493 |
| a dna polymerase from the archaeon sulfolobus solfataricus shows sequence similarity to family b dna polymerases. | the gene encoding the thermostable dna polymerase from the archaeon sulfolobus solfataricus (strain mt 4) was isolated by means of two degenerate oligonucleotide probes. they were designed on the basis of partial enzyme amino acid sequences. the gene was found to encode a 882 residues polypeptide chain with a deduced molecular mass of about 100 kda. by comparison with other archaeal genes, putative regulatory sites were identified in the gene-flanking regions. by computer-assisted homology searc ... | 1992 | 1614858 |
| resonance raman study of cytochrome aa3 from sulfolobus acidocaldarius. | the single subunit terminal oxidase of sulfolobus acidocaldarius, cytochrome aa3, was studied by resonance raman spectroscopy. results on the fully oxidized, the fully reduced, and the reduced carbon monoxide complex are reported and compared with those of eucaryotic cytochrome oxidase. it is shown that in both redox states the hemes a and a3 are in the six-coordinated low-spin and six-coordinated high-spin configuration, respectively. the resonance raman spectra reveal far-reaching similarities ... | 1991 | 1645292 |
| s-adenosylmethionine decarboxylase from the thermophilic archaebacterium sulfolobus solfataricus. purification, molecular properties and studies on the covalently bound pyruvate. | s-adenosylmethionine decarboxylase from sulfolobus solfataricus, a thermoacidophilic archaebacterium optimally growing at 87 degrees c, has been purified to homogeneity. the specific activity of the homogeneous enzyme is 12 nmol co2 formed min-1 (mg protein)-1 and the overall yield 8%. the enzyme is thermophilic with an optimum at 75 degrees c, is thermostable, and does not require divalent cations or putrescine for activity. it has a molecular mass of 32 kda, and appears to be a monomeric prote ... | 1991 | 1649051 |
| a gene in the archaebacterium sulfolobus solfataricus that codes for a protein equivalent to the alpha subunits of the signal recognition particle receptor in eukaryotes. | we have sequenced a gene in the archaebacterium sulfolobus solfataricus that codes for a protein that shows sequence similarity to the alpha subunit of the signal recognition particle receptor or docking protein in eukaryotes and the product of the ftsy gene in escherichia coli. comparison of the sulfolobus 'docking protein' with its eukaryotic and eubacterial counterparts showed that the region of highest sequence similarity corresponds to a gtp-binding site. the presence of this gene in archae ... | 1991 | 1658539 |
| glutamate dehydrogenase from the thermoacidophilic archaebacterium sulfolobus solfataricus. | an nad(p)-dependent glutamate dehydrogenase was purified to homogeneity from the thermoacidophilic archaebacterium sulfolobus solfataricus. the enzyme is a hexamer (subunit mass 45 kda) which dissociates into lower states of association when submitted to gel filtration. isoelectric focusing analysis of the purified enzyme showed a pi of 5.7 and occasionally revealed microheterogeneity. the enzyme is strictly specific for the natural substrates 2-oxoglutarate and l-glutamate, but is active with b ... | 1991 | 1901040 |
| cell biology. a cytoplasmic chaperonin? | | 1991 | 1684221 |
| characterization of amino acid aminotransferases of methanococcus aeolicus. | four aminotransferases were identified and characterized from methanococcus aeolicus. branched-chain aminotransferase (bcat, ec 2.6.1.42), aspartate aminotransferase (aspat, ec 2.6.1.1), and two aromatic aminotransferases (ec 2.6.1.57) were partially purified 175-, 84-, 600-, and 30-fold, respectively. the apparent molecular weight, substrate specificity, and kinetic properties of the bcat were similar to those of other microbial bcats. the aspat had an apparent molecular weight of 162,000, whic ... | 1992 | 1729242 |
| component h of the dna-dependent rna polymerases of archaea is homologous to a subunit shared by the three eucaryal nuclear rna polymerases. | the gene encoding component h of the dna-dependent rna polymerase (rnap, ec 2.7.7.6) of sulfolobus acidocaldarius has been identified by comparison of the amino acid sequence with the derived amino acid sequence of an open reading frame (orf88) in the rnap operon. corresponding genes were identified in halobacterium halobium and were cloned and sequenced from thermococcus celer and methanococcus vannielii. all these rpoh genes are situated between the promoters of the rnap operons and the corres ... | 1992 | 1729711 |
| the protein sequence of glutamate dehydrogenase from sulfolobus solfataricus, a thermoacidophilic archaebacterium. is the presence of n-epsilon-methyllysine related to thermostability? | the complete amino acid sequence of glutamate dehydrogenase from the thermoacidophilic archaebacterium sulfolobus solfataricus has been determined. the sequence was reconstructed by automated sequence analysis of peptides obtained after cleavage by trypsin, cyanogen bromide, staphylococcus aureus v8 protease and pepsin. the enzyme subunit is composed of 421 amino acid residues yielding a molecular mass of 46.078 kda. the presence of n-epsilon-methyllysine in six positions of the sequence was obs ... | 1992 | 1730244 |
| structure function relationships in the ribosomal stalk proteins of archaebacteria. | the ribosomal l12 protein gene of sulfolobus solfataricus (ssol12) has been subcloned and overexpressed in escherichia coli. five protein l12 mutants were designed: two nh2-terminal and two cooh-terminal truncated mutants and one mutant lacking the highly charged part of the cooh-terminal region. the mutant protein genes were overexpressed in e. coli and the products purified. the amino acid composition was verified and the nh2 terminally truncated mutants were subjected to edman degradation. th ... | 1992 | 1730657 |
| expression of the thermostable beta-galactosidase gene from the archaebacterium sulfolobus solfataricus in saccharomyces cerevisiae and characterization of a new inducible promoter for heterologous expression. | the lacs gene from the extremely thermoacidophilic archaebacterium sulfolobus solfataricus encodes an enzyme with beta-galactosidase activity that, like other enzymes from this organism, is exceptionally thermophilic (optimal activity above 90 degrees c), thermostable, and resistant to common protein denaturants and proteases. expression of the gene in mesophilic hosts is needed to uncover the molecular nature of these features. we have obtained expression of beta-galactosidase in saccharomyces ... | 1992 | 1732221 |
| determination of peptide regions on the surface of the eubacterial and archaebacterial ribosome by limited proteolytic digestion. | limited proteolysis was used in combination with two-dimensional gel electrophoresis, blotting, and amino acid sequence analysis to investigate the surface of intact ribosomal subunits at the peptide and amino acid level. surface sites of 14 ribosomal proteins from escherichia coli 50s subunits were determined using proteases with different specificities. to assess the evolutionary conservation of ribosomal topography among eubacteria, large subunits from bacillus stearothermophilus were also su ... | 1991 | 1751495 |
| genetic engineering and overexpression of ribosomal l12 protein genes from three different archaebacteria in e coli. | genes coding for ribosomal protein l12 from methanococcus vannielii (mva), halobacterium halobium (hha) and sulfolobus solfataricus (sso) have been subcloned in the polylinker region of puc19. an efficient shine-dalgarno sequence has been attached to the 5' end of the genes, and two ochre stop codons have been created at their 3' ends, where necessary. in addition, mutants of the mval12 and hhal12 genes were constructed, which coded for a cysteine residue at the c-terminus of the protein. the co ... | 1991 | 1764512 |
| the binding site of ribosomal protein l10 in eubacteria and archaebacteria is conserved: reconstitution of chimeric 50s subunits. | it has been shown by electron microscopy that the selective removal of the stalk from 50s ribosomal subunits of two representative archaebacteria, namely methanococcus vaniellii and sulfolobus solfataricus, is accompanied by loss of the archaebacterial l10 and l12 proteins. the stalk was reformed if archaebacterial core particles were reconstituted with their corresponding split proteins. next, structurally intact chimeric 50s subunits have been reconstituted in vitro by addition of escherichia ... | 1991 | 1764524 |
| crystallization and preliminary x-ray studies on sulfolobus acidocaldarius ferredoxin. | ferredoxin from a thermoacidophilic archaebacterium, sulfolobus acidocaldarius, has been crystallized. the space group is p4(3)2(1)2 or p4(1)2(1)2 and the cell dimensions are a = b = 50.12 a and c = 69.52 a. the vm value is calculated to be 1.88 a3/da, assuming one molecule per asymmetric unit. the crystal diffracts x-rays beyond 2.0 a resolution. | 1991 | 1778971 |
| thermopsin, a thermostable acid protease from sulfolobus acidocaldarius. | | 1991 | 1812713 |
| the atp synthase of halobacterium salinarium (halobium) is an archaebacterial type as revealed from the amino acid sequences of its two major subunits. | the head piece of the a-type atp synthase in an extremely halophilic archaebacterium, namely halobacterium salinarium (halobium), is composed of two kinds of subunit, alpha and beta, and is associated with atp-hydrolyzing activity. the genes encoding these subunits with hydrolytic activity have been cloned and sequenced. the putative amino acid sequences of the alpha and beta subunits deduced from the nucleotide sequences of the genomic dna consist of 585 and 471 residues, respectively. the amin ... | 1991 | 1832829 |
| purification and characterization of atpase from nitrobacter winogradskyi. | an atpase was purified from nitrobacter winogradskyi, and some of its molecular and enzymatic properties were determined. the enzyme was composed of two subunits of 64 and 59 kda, respectively. the enzyme had its ph optimum at 9.5 and showed a specific activity of 7 units per mg protein. this activity was about 14% and 18% of that of f1-atpases obtained from escherichia coli and sulfolobus acidocaldarius, respectively. the enzyme was 29% and 6% inhibited by 100 microm dicyclohexylcarbodiimide (d ... | 1991 | 1834519 |
| a molecular chaperone from a thermophilic archaebacterium is related to the eukaryotic protein t-complex polypeptide-1. | there is evidence to suggest that components of archaebacteria are evolutionarily related to cognates in the eukaryotic cytosol. we postulated that the major heat-shock protein of the thermophilic archaebacterium, sulfolobus shibatae, is a molecular chaperone and that it is related to an as-yet unidentified chaperone component in the eukaryotic cytosol. acquired thermotolerance in s. shibatae correlates with the predominant synthesis of this already abundant protein, referred to as thermophilic ... | 1991 | 1836250 |
| molecular cloning of genes encoding major two subunits of a eubacterial v-type atpase from thermus thermophilus. | the atpab genes which encode the alpha and beta subunits of membrane atpase from a thermophilic eubacterium, thermus thermophilus hb8, were cloned. the deduced amino-acid sequences of the alpha subunit (583 amino acids) and the beta subunit (478 amino acids) are only moderately similar to the alpha beta subunits of the f0f1-atpases, while they are highly similar to the major two subunits of the v-type atpases, a family of atpases which have been so far found in eukaryotic endomembrane vacuolar v ... | 1991 | 1836357 |
| the structure of the gene for ribosomal protein l5 in the archaebacterium sulfolobus acidocaldarius. | the gene for the ribosomal protein l5 from the archaebacterium sulfolobus acidocaldarius has been isolated and sequenced. the gene codes for a basic protein of molecular weight 29 165 da. this protein shows substantial similarity to the equivalent protein from other archaebacteria as well as from yeast, and considerably less similarity to the equivalent eubacterial protein. these results support the concept of the archaebacteria as a monophyletic kingdom more closely related to eukaryotes than t ... | 1991 | 1840500 |
| purification and properties of an extreme thermostable glutamate dehydrogenase from the archaebacterium sulfolobus solfataricus. | glutamate dehydrogenase (l-glutamate:nad(p)+ oxidoreductase, deaminating, ec 1.4.1.3.) of the extreme thermophilic archaebacterium sulfolobus solfataricus was purified to homogeneity by (nh4)2so4 fractionation, anion-exchange chromatography and affinity chromatography on 5'-amp-sepharose. the purified native enzyme had a mr of about 270,000 and was shown to be a hexamer of subunit mr of 44,000. it was active from 30 to 95 degrees c, with a maximum activity at 85 degrees c. no significant loss of ... | 1991 | 1899341 |
| identification and characterization of a defective ssv1 genome integrated into a trna gene in the archaebacterium sulfolobus sp. b12. | within the chromosome of the archaebacterium sulfolobus sp. b12, a 7.4 kb region was identified which displayed extensive sequence similarities to the 15.5 kb genetic element ssv1 carried by the same strain both as a circular form and as a site-specifically integrated copy. dna sequence analysis indicated that this 7.4 kb region (designated ssv1intb) represented an ssv1-like element distinguishable from the full-length integrated copy (designated ssv1inta) by extensive deletions and point mutati ... | 1990 | 1691436 |
| isolate b12, which harbours a virus-like element, represents a new species of the archaebacterial genus sulfolobus, sulfolobus shibatae, sp. nov. | the sulfolobus isolate b12 and its endogenous virus-like element ssv1 have provided a fruitful system for detailed analysis of certain aspects of archaebacterial molecular biology, especially those concerning gene expression. in the course of clarifying this isolate's taxonomic position, we determined dna base composition, ability to grow autotrophically, nucleotide sequence of 16s ribosomal rna, and level of total genomic homology to other sulfolobus strains. although the results generally demo ... | 1990 | 1703758 |
| a small basic ribosomal protein from the extreme thermophilic archaebacterium sulfolobus solfataricus that has no equivalent in escherichia coli. | the structure of the gene for a small, very basic ribosomal protein in sulfolobus solfataricus has been determined and the structure of the protein coded by this gene has been confirmed by partial amino acid sequencing. the protein shows no sequence similarity to any of the ribosomal proteins from eubacteria (escherichia coli) or to those that have been reported from eukaryotes. | 1991 | 1711982 |
| nucleotide sequence of a dna region comprising the gene for elongation factor 1 alpha (ef-1 alpha) from the ultrathermophilic archaeote pyrococcus woesei: phylogenetic implications. | the gene encoding elongation factor 1 alpha (ef-1 alpha, 1290 bp) of the ultrathermophilic, sulfur-reducing archaeote pyrococcus woesei was localized within a bg/ii fragment of chromosomal dna. sequence analysis showed that the ef-1 alpha gene is the upstream unit of a three-gene cluster comprising the genes for ribosomal protein s10 (306 bp) and transfer rnaser (gga). the three genes follow each other immediately in the order ef-1 alpha.s10.trna(ser) after a putative promoter located 55 bp upst ... | 1991 | 1723106 |
| translation and ribosome assembly in extremely thermophilic archaebacteria. | several features of translation and ribosome structure in extremely thermophilic, sulfur-dependent archaebacteria are described, including: i) a peculiar mechanism of transfer rna-mediated 70s ribosome formation from free subunits; ii) poly(u)translation by hybrid ribosomes composed by one archaebacterial and one eucaryotic subunit; iii) ribosome assembly and homologous and heterologous rna/protein recognition. | 1991 | 1725258 |
| heterologous in vitro transcription from two archaebacterial promoters. | a cell-free extract of sulfolobus shibatae is able to specifically initiate transcription in vitro at the promoter of the plasmid-encoded gene for the major gas vesicle protein of halobacterium halobium and at the promoter for the transcript t4 of the temperate h. halobium phage phi h. the corresponding promoter from the virulent phage mutant phi hl1 yields enhanced transcription in the heterologous system, in agreement with strongly increased in vivo expression. | 1991 | 1906812 |
| properties of the elongation factor 1 alpha in the thermoacidophilic archaebacterium sulfolobus solfataricus. | the elongation factor 1 alpha (aef-1 alpha) was purified to homogeneity from the thermoacidophilic archaebacterium sulfolobus solfataricus by chromatographic procedures utilising deae-sepharose, hydroxyapatite and fplc on mono s. the purified protein binds [3h]gdp at a 1:1 molar ratio and it is essential for poly(phe) synthesis in vitro; it also binds gtp but not atp. these findings indicate that aef-1 alpha is the counterpart of the eubacterial elongation factor tu (ef-tu). purified aef-1 alpha ... | 1991 | 1907914 |
| structure of the beta-glucosidase gene bgla of clostridium thermocellum. sequence analysis reveals a superfamily of cellulases and beta-glycosidases including human lactase/phlorizin hydrolase. | the nucleotide sequence of the clostridium thermocellum gene bgla, coding for the thermostable beta-glucosidase a, has been determined. the coding region of 1344 bp was identified by comparison with the n-terminal amino acid squence of recombinant beta-glucosidase a purified from escherichia coli. the deduced amino acid sequence corresponds to a protein of 51,482 da. the coding region is flanked by putative promoter and transcription terminator sequences. the protein is unrelated to beta-glucosi ... | 1991 | 1909624 |
| electromechanical stability of planar lipid membranes from bipolar lipids of the thermoacidophilic archebacterium sulfolobus acidocaldarius. | stable planar membranes have been obtained from the bipolar lipid glycerol dialkyl nonitol tetraether (gdnt) extracted from the thermoacidophilic archebacterium sulfolobus acidocaldarius. the electric capacity cm, the resistance rm and tension sigma of these membranes were measured. the dependence of the bipolar lipid membranes mean life time tau 1 on voltage was investigated. it was shown that the irreversible electric breakdown of membranes from gdnt and usual phospholipids is due to the same ... | 1991 | 1911833 |
| initiation of translation at an aua codon for an archaebacterial protein gene expressed in e.coli. | overexpression of the sulfolobus solfataricus l12 ribosomal protein gene in e.coli cells yielded two products of different size. if the e.coli cells carrying the overexpression plasmid were induced in the early stage of bacterial growth, the smaller of the two products was almost exclusively produced. however, induction in a late stage of bacterial growth yielded the larger product in significant excess. the larger protein was identified as the translation product of the entire ssol12 gene, whil ... | 1991 | 1923803 |
| sequence homology between a beta-galactosidase and some beta-glucosidases. | a significant sequence homology was found between a thermostable beta-galactosidase from sulfolobus solfataricus and two beta-glucosidases, respectively, from caldocellum saccharolyticum and from agrobacterium sp. these glycosidases appear to form a new protein family, since no homology could be detected with established beta-galactosidase or beta-glucosidase families. | 1991 | 1924272 |
| complete nucleotide sequence of the virus ssv1 of the archaebacterium sulfolobus shibatae. | the dna sequence of the sulfolobus shibatae virus ssv1 is the first complete sequence of an archaebacterial virus genome. the viral dna is a closed double-stranded dna circle of 15465 bp. the features of the sequence, the positions of all 11 transcripts, the three characterized proteins, and the open reading frames are described. | 1991 | 1926776 |
| purification and characterisation of an archaebacterial succinate dehydrogenase complex from the plasma membrane of the thermoacidophile sulfolobus acidocaldarius. | a succinate dehydrogenase complex was isolated in a three-step purification from plasma membranes of the thermoacidophilic archaebacterium sulfolobus acidocaldarius. it consists of four subunits: a, 66 kda; b, 31 kda; c, 28 kda and d, 12.8 kda. in the 141-kda native protein, the four subunits are present in an equimolar stoichiometry. the complex contains acid-non-extractable flavin, iron and acid-labile sulphide. maximal succinate dehydrogenase activities were recorded at ph 6.5, which coincide ... | 1991 | 1935955 |
| purification and spectral characterization of a b-type cytochrome from the plasma membrane of the archaebacterium sulfolobus acidocaldarius. | for the first time the purification of a heme-b containing cytochrome from the plasma membrane of an extremely thermoacidophilic archaebacterium is described. the detergent solubilized 30 kda polypeptide contains two heme-b centers and one copper ion. according to its low temperature spectra and co-binding properties, it is likely to function as a cytochrome-o like terminal oxidase in the membrane. the purified cytochrome does not retain catalytic activity, however. | 1991 | 1936283 |
| positive selection for uracil auxotrophs of the sulfur-dependent thermophilic archaebacterium sulfolobus acidocaldarius by use of 5-fluoroorotic acid. | uracil auxotrophs of sulfolobus acidocaldarius were positively selected by using 5-fluoroorotic acid. the wild-type strain was unable to grow in medium containing 5-fluoroorotic acid, whereas the mutants grew normally. positive selection could be done for the auxotrophs. mutants deficient in orotidine-5'-monophosphate pyrophosphorylase activity were isolated. | 1991 | 1938966 |
| selectable mutant phenotypes of the extremely thermophilic archaebacterium sulfolobus acidocaldarius. | as a first step toward developing the genetic potential of extremely thermophilic archaebacteria, mutant strains of sulfolobus acidocaldarius were selected by plating cells directly on solid medium containing one of several growth inhibitors. three spontaneous resistance phenotypes were observed (5-fluorouracil resistance, novobiocin resistance, and l-ethionine resistance), each at a different average frequency. characterization of representative strains showed each of the three mutant phenotype ... | 1991 | 1938972 |
| protein topography of sulfolobus solfataricus ribosomes by cross-linking with 2-iminothiolane. sso l12e, sso l10e, and sso l11e are neighbors. | large ribosomal subunits from sulfolobus solfataricus were cross-linked with 2-iminothiolane in order to investigate the arrangement of proteins in the region containing the multicopy acidic protein sso l12e, the protein homologous to escherichia coli l7/l12. proteins from cross-linked 50 s subunits were extracted and fractionated by chromatography on cm-cellulose. fractions containing sso l12e were analyzed by "diagonal" (two-dimensional reducing/nonreducing) dodecyl sulfate polyacrylamide gel ... | 1991 | 1939187 |
| comparison of the structure of archaebacterial ribosomal proteins equivalent to proteins l11 and l1 from escherichia coli ribosomes. | the sequences of two ribosomal proteins from two widely divergent species of archaebacteria, halobacterium cutirubrum and sulfolobus solfataricus, have been deduced from the structure of their respective genes. these two proteins were found to be equivalent to the l11 and l1 ribosomal proteins of the eubacterium escherichia coli. sequence comparison revealed that the archaebacterial l11e (equivalent to e. coli l11) proteins are longer than the eubacterial protein due to a c-terminal extension of ... | 1991 | 1946333 |
| the active site of sulfolobus solfataricus aspartate aminotransferase. | aspartate aminotransferase from the archaebacterium sulfolobus solfataricus binds pyridoxal 5' phosphate, via an aldimine bond, with lys-241. this residue has been identified by reducing the enzyme in the pyridoxal form with sodium cyanoboro[3h]hydride and sequencing the specifically labeled peptic peptides. the amino acid sequence centered around the coenzyme binding site is highly conserved between thermophilic aspartate aminotransferases and differs from that found in mesophilic isoenzymes. a ... | 1991 | 1954227 |
| archaebacterial atpases: relationship to other ion-translocating atpase families examined in terms of immunological cross-reactivity. | immunological cross-reactivity among three types of h(+)-atpases, that is, three archaebacterial atpases, the f1-atpase from thermophilic bacterium ps3 (tf1) and the vacuolar membrane atpase from saccharomyces cerevisiae, was examined by means of immunoblot analyses. the three archaebacterial atpases were very similar in immunological cross-reactivity, suggesting that they belong to the same family of atpases. cross-reaction was also observed between the atpase from sulfolobus acidocaldarius, on ... | 1990 | 1963431 |
| cloning and nucleotide sequence of an archaebacterial glutamine synthetase gene: phylogenetic implications. | the glna gene of the thermophilic sulphur-dependent archaebacterium sulfolobus solfataricus was identified by hybridization with the corresponding gene of the cyanobacterium spirulina platensis and cloned in escherichia coli. the nucleotide sequence of the 1696 bp dna fragment containing the structural gene for glutamine synthetase was determined, and the derived amino acid sequence (471 residues) was compared to the sequences of glutamine synthetases from eubacteria and eukaryotes. the homology ... | 1990 | 1973523 |
| gene for the adp-ribosylatable elongation factor 2 from the extreme thermoacidophilic archaebacterium sulfolobus acidocaldarius. cloning, sequencing, comparative analysis. | the gene coding for adp-ribosylatable elongation factor 2 (ef-2) from the extreme thermoacidophilic archaebacterium sulfolobus acidocaldarius has been cloned and its sequence is reported. amino acid sequence comparisons showed that ef-2 from s. acidocaldarius is more closely related to eukaryotic ef-2 than to eubacterial ef-g. consensus sequences are derived from comparison of a region around the unique amino acid diphthamide, which is the target for adp-ribosylation by diphtheria toxin in archa ... | 1991 | 1900048 |
| distribution of folates and modified folates in extremely thermophilic bacteria. | analyses were made of the structures and levels of folates and modified folates present in extremely thermophilic bacteria. these procedures involved the chemical analysis of products resulting from the oxidative cleavage of the 6-substituted, folatelike tetrahydropterins present in the cells. air-oxidized cell extracts of extreme thermophiles from two members of the archaebacterial order thermococcales, thermococcus celer and pyrococcus furiosus, contained only 7-methylpterin, indicating that t ... | 1991 | 1900506 |
| early assembly proteins of the large ribosomal subunit of the thermophilic archaebacterium sulfolobus. identification and binding to heterologous rrna species. | studies of ribosome structure in thermophilic archaebacteria may provide valuable information on (i) the mechanisms involved in the stabilization of nucleic acid-protein complexes at high temperatures and (ii) the degree of evolutionary conservation of the ribosomal components in the primary kingdoms of cell descent. in this work we investigate certain aspects of rna/protein interaction within the large ribosomal subunits of the extremely thermophilic archaebacterium sulfolobus solfataricus. the ... | 1991 | 1901059 |
| transsulfuration in archaebacteria. | the transfer of sulfur from methionine to cysteine in the archaebacteria sulfolobus acidocaldarius and halobacterium marismortui was studied by feeding 34s-labeled methionine to cells and measuring the incorporation of 34s into protein-bound cellular cysteine and methionine by mass spectrometry. it was found that, as are eucaryotes, both of these archaebacteria were able to convert the sulfur of methionine to cysteine. | 1991 | 1902467 |
| thermostable aspartate aminotransferase from a thermophilic bacillus species. gene cloning, sequence determination, and preliminary x-ray characterization. | the gene encoding aspartate aminotransferase of a thermophilic bacillus species, ym-2, has been cloned and expressed efficiently in escherichia coli. the primary structure of the enzyme was deduced from nucleotide sequences of the gene and confirmed mostly by amino acid sequences of tryptic peptides. the gene consists of 1,176 base pairs encoding a protein of 392 amino acid residues; the molecular mass of the enzyme subunit is estimated to be 42,661 daltons. the active site lysyl residue that bi ... | 1991 | 1990006 |
| isolation and characterization of an intracellular aminopeptidase from the extreme thermophilic archaebacterium sulfolobus solfataricus. | an intracellular aminopeptidase (ec 3.4.11.-) was purified from the extreme thermophilic archaebacterium, sulfolobus solfataricus. the molecular weight of the native enzyme was about 320,000, as calculated by gel-filtration studies, and a subunit mr of 80,000 was estimated by sds-polyacrylamide gel electrophoresis. the temperature optimum of the enzyme was at 75 degrees c and the ph optimum was found to be 6.5. the aminopeptidase was highly active against the chromogenic substrates l-leu-p-na an ... | 1990 | 2106344 |
| acquired thermotolerance and heat shock in the extremely thermophilic archaebacterium sulfolobus sp. strain b12. | the extreme thermophile sulfolobus sp. strain b12 exhibits an acquired thermotolerance response. thus, survival of cells from a 70 degrees c culture at the lethal temperature of 92 degrees c was enhanced by as much as 6 orders of magnitude over a 2-h period if the culture was preheated to 88 degrees c for 60 min or longer before being exposed to the lethal temperature. in eubacteria and eucaryotes, acquired thermotolerance correlates with the induced synthesis of a dozen or so proteins known as ... | 1990 | 2106513 |
| structure, organization and evolution of the l1 equivalent ribosomal protein gene of the archaebacterium methanococcus vannielii. | the gene for ribosomal protein mval1 from the arachaebacterium methanococcus vannielii was cloned and characterized. it is clustered together with the genes for mval10 and mval12, thus is organized in the same order as in e.coli and other archaebacteria. unexpectedly, analysis of the sequence in front of the mval1 gene revealed an orf of unknown identity, whereas in e.coli, halobacterium and sulfolobus solfataricus the gene for the l11 equivalent protein is located in this position. northern blo ... | 1990 | 2107529 |
| pyrite oxidation by thermophilic archaebacteria. | three species of thermophilic archaebacteria of the genera sulfolobus (sulfolobus acidocaldarius and s. solfataricus) and acidianus (acidianus brierleyi) were tested for their ability to oxidize pyrite and to grow autotrophically on pyrite, to explore their potential for use in coal desulfurization. only a. brierleyi was able to oxidize and grow autotrophically on pyrite. jarosite was formed during the pyrite oxidation, resulting in the precipitation of sulfate and iron. the medium composition a ... | 1990 | 2107795 |
| circular chromosomal dna in the sulfur-dependent archaebacterium sulfolobus acidocaldarius. | the shape of the chromosomal dna of the sulfur-dependent archaebacterium sulfolobus acidocaldarius was analyzed by the pulsed-field gel electrophoresis(pfge). s.acidocaldarius dna digested with notl showed two dna bands at around 1.0 mbp and 2.1 mbp. notl-linking clones were isolated from the library of s.acidocaldarius chromosomal dna. it contained two notl sites. both 1.0 and 2.1 mbp dna band separated by pfge were hybridized with the two independent notl-linking fragment. each right and left ... | 1990 | 2108430 |
| calditol tetraether lipids of the archaebacterium sulfolobus solfataricus. biosynthetic studies. | lipids from the archaebacterium sulfolobus solfataricus are based on 72-membered macrocyclic tetraethers made up from two c40 diol units differently cyclized and either two glycerol moieties or one glycerol moiety and a unique branched-chain nonitol named calditol (glycerodialkylnonitol tetraethers, gdnts). to elucidate the biosynthesis of calditol and related tetraethers, labelled precursors, [u-14c,1(3)-3h]glycerol, [u-14c,2-3h]glycerol, d-[1-14c,6-3h]glucose, d-[6-14c,1-3h]glucose, d-[1-14c,2 ... | 1990 | 2109600 |
| purification and properties of a thermophilic and thermostable dna polymerase from the archaebacterium sulfolobus solfataricus. | a dna-dependent dna polymerase was obtained in homogenous form from the thermoacidophilic archaebacterium sulfolobus solfataricus. the enzyme, purified 706-fold, has a molecular mass of about 110000 daltons as determined by gel filtration and by glycerol gradient centrifugation. it requires mg++ for its activity and has a ph optimum of 7.7. the activity is sharply dependent on the ionic strength. the enzyme is thermostable; its properties and activity requirements were characterized. the feature ... | 1990 | 2113898 |
| characterization of ribonuclease p from the archaebacterium sulfolobus solfataricus. | ribonuclease p is the endonuclease that removes the leader fragments from the 5'-ends of precursor trnas. the enzyme isolated from eubacteria contains a catalytic rna subunit. rnas also copurify with eukaryotic rnase p, although catalysis by those rnas has not been demonstrated. this paper reports the isolation and characterization of ribonuclease p from the thermoacidophilic archaebacterium sulfolobus solfataricus. archaebacteria are a primary evolutionary lineage, distinct from both eukaryotes ... | 1990 | 2115885 |
| in vitro transcription of two rrna genes of the archaebacterium sulfolobus sp. b12 indicates a factor requirement for specific initiation. | we describe a cell-free transcription system for the archaebacterium sulfolobus sp. b12 that specifically initiates transcription at the 5s rrna-encoding dna and the 16s/23s rrna-encoding dna promoters of the same species. with this crude extract system, specific initiation was absolutely dependent on the box a motif, a highly conserved promoter element in archaebacteria located approximately 25 base pairs upstream of transcription initiation sites. in vitro transcription of the rrna genes by pu ... | 1990 | 2116009 |
| structure of the archaebacterial 7s rna molecule. | the genes encoding the 7s rnas of the archaebacteria archaeoglobus fulgidus, methanosarcina acetivorans, sulfolobus, solfataricus, and thermococcus celer have been isolated. all four genes occur as single genomic copies and are flanked by sequences containing potential signals for transcriptional promotion and termination. the genes encode rna molecules approximately 300 nucleotides in length which conform strictly to a model of secondary structure common to all described archaebacterial 7s rnas ... | 1990 | 2116588 |