| immunochemical detection of adp-ribosylating enzymes in the archaeon sulfolobus solfataricus. | polyclonal antibodies raised against eukaryotic mono-(adpribose)transferase and poly(adpribose)polymerase were used to test the presence of antigenic determinants in a crude extract of sulfolobus solfataricus, a thermophilic archaeon. samples from eukaryotic (bull testis) and bacterial (e. coli) sources were analysed for comparison. all tested antibodies reacted with the sulfolobal sample with a specificity comparable to that of the eukaryotic preparation, as revealed by elisa test, activity ass ... | 1996 | 8549833 |
| a protein-serine phosphatase from the halophilic archaeon haloferax volcanii. | we have detected a protein phosphatase activity in soluble extracts from the halophilic archaeon haloferax volcanii. this activity was markedly stimulated by the divalent metal ions mn2+ and cd2+. it dephosphorylated phosphoseryl residues in casein, mixed histones, and phosphorylase a, but not phosphotyrosyl residues in reduced, carboxyamidomethylated and maleylated lysozyme. this protein phosphatase activity was inhibited by naf, zn2+, vanadate, molybdate, inorganic phosphate, inorganic pyropho ... | 1993 | 8394705 |
| isolation and characterization of flagella and flagellin proteins from the thermoacidophilic archaea thermoplasma volcanium and sulfolobus shibatae. | isolated flagellar filaments of sulfolobus shibatae were 15 nm in diameter, and they were composed of two major flagellins which have m(r)s of 31,000 and 33,000 and which stained positively for glycoprotein. the flagellar filaments of thermoplasma volcanium were 12 nm in diameter and were composed of one major flagellin which has an m(r) of 41,000 and which also stained positively for glycoprotein. n-terminal amino acid sequencing indicated that 18 of the n-terminal 20 amino acid positions of th ... | 1996 | 8550530 |
| dtmp biosynthesis in archaea. | the biosynthesis of dtmp has been studied in cell extracts of two different members of the domain archaea, methanosarcina thermophila and sulfolobus solfataricus. in m. thermophila, the dtmp was formed from dump and [methylene-2h2]-5,10-methylenetetrahydrosarcinapterin generated in situ from added [methylene-2h2] formaldehyde and the tetrahydrosarcinapterin present in the cell extract. in s. solfataricus, the 5,10-methyl-enetetrahydro derivative of a synthetic fragment of sulfopterin, the modifi ... | 1996 | 8550533 |
| activation of sulfolobus solfataricus alcohol dehydrogenase by modification of cysteine residue 38 with iodoacetic acid. | reaction of thermostable nad(+)-dependent alcohol dehydrogenase from sulfolobus solfataricus with iodoacetate at ph 9.0 and 37 degrees c significantly increases the oxidation rate of aliphatic and aromatic alcohols and decreases the reduction rate of aromatic aldehydes. the archaeal adh is chemically modified and activated in a michaelis-menten-type reaction, where one molecule of the reagent binds per active site. nad+ in micromolar concentration protects the enzyme against the inhibitor in an ... | 1996 | 8555238 |
| tryptophan biosynthesis genes trpegc in the thermoacidophilic archaebacterium sulfolobus solfataricus. | a dna fragment containing the trpegc gene cluster was isolated from the thermoacidophilic archaebacterium sulfolobus solfataricus. the products of trpe, trpg, and trpc from s. solfataricus were compared to the homologous products from a eukaryote, a eubacterium, and two archaebacteria, namely, a methanogen and an extreme halophile. they appeared to be equally related to the proteins from escherichia coli and saccharomyces cerevisiae, the percentages of conserved amino acids being roughly the sam ... | 1993 | 8416906 |
| the glucose effect and regulation of alpha-amylase synthesis in the hyperthermophilic archaeon sulfolobus solfataricus. | an alpha-amylase was purified from culture supernatants of sulfolobus solfataricus 98/2 during growth on starch as the sole carbon and energy source. the enzyme is a homodimer with a subunit mass of 120 kda. it catalyzes the hydrolysis of starch, dextrin, and alpha-cyclodextrin with similar efficiencies. addition of exogenous glucose represses production of alpha-amylase, demonstrating that a classical glucose effect is operative in this organism. synthesis of [35s]-alpha-amylase protein is also ... | 1996 | 8576067 |
| structure-based sequence alignment of elongation factors tu and g with related gtpases involved in translation. | the g domain and domain ii in the crystal structure of thermus thermophilus elongation factor g (ef-g) were compared with the homologous domains in thermus aquaticus elongation factor tu (ef-tu). sequence alignment derived from the structural superposition was used to define conserved sequence elements in domain ii. these elements and previously known conserved sequence elements in the g domain were used to guide the alignment of the sequences of sulfolobus acidocaldarius elongation factor 2, hu ... | 1995 | 8587108 |
| ssv1-encoded site-specific recombination system in sulfolobus shibatae. | we present evidence for the existence of a conservative site-specific recombination system in archaea by demonstrating integrative recombination of sulfolobus shibatae virus ssv1 dna with the host chromosome, catalysed by the ssv1-encoded integrase in vitro. the putative int gene of ssv1 was expressed in escherichia coli yielding a protein of about 39 kda. this protein alone efficiently recombined linear dna substrates containing chromosomal (atta) and viral (attp) attachment sites; recombinatio ... | 1993 | 8483447 |
| a potential anti-oxidant protein in a ferrous iron-oxidizing sulfolobus species. | the production of a 25 kda protein was greatly increased when a sulfur- and ferrous iron-oxidizing species of sulfolobus was switched from growth on tetrathionate to growth on ferrous iron. the gene encoding the protein was cloned and sequenced. the predicted amino sequence showed significant similarity to those of the alkyl hydroperoxide reductase/thiol specific anti-oxidant family of proteins that appear to be involved in responses to certain types of oxidative stress. | 1995 | 8593961 |
| comparative analysis of ribonuclease p rna structure in archaea. | although the structure of the catalytic rna component of ribonuclease p has been well characterized in bacteria, it has been little studied in other organisms, such as the archaea. we have determined the sequences encoding rnase p rna in eight euryarchaeal species: halococcus morrhuae, natronobacterium gregoryi, halobacterium cutirubrum, halobacteriurn trapanicum, methanobacterium thermoautotrophicum strains deltah and marburg, methanothermus fervidus and thermococcus celer strain al-1. on the b ... | 1996 | 8614627 |
| cloning of a potential cytochrome p450 from the archaeon sulfolobus solfataricus. | abstract a gene, cyp119, for a potential cytochrome p450 has been isolated and sequenced from the extreme acidothermophilic archaeon sulfolobus solfataricus. the gene predicts a polypeptide of 368 amino acids containing the consensus heme-binding sequence phe-gly-xaa-gly-xaa-his-xaa-cys-xaa-gly- xaa3-ala-arg-xaa-glu. it most closely resembles the cytochrome p450s found in the bacterium bacillus subtilis, with which it shares 129 identical amino acid residues (35%). this first sequence of a poten ... | 1996 | 8617361 |
| cloning and overexpression in escherichia coli of the genes encoding nad-dependent alcohol dehydrogenase from two sulfolobus species. | the gene adh encoding a nad-dependent alcohol dehydrogenase from the novel strain rc3 of sulfolobus sp. was cloned and sequenced. both the adh gene from sulfolobus sp. strain rc3 and the alcohol dehydrogenase gene from sulfolobus solfataricus (dsm 1617) were expressed at a high level in escherichia coli, and the recombinant enzymes were purified, characterized, and compared. only a few amino acid replacements were responsible for the different kinetic and physicochemical features investigated. | 1996 | 8550434 |
| on the origin of respiration: electron transport proteins from archaea to man. | all aerobic organisms use the exergonic reduction of molecular oxygen to water as primary source of metabolic energy. this reaction is catalyzed by membrane residing terminal heme/cu-oxidases which belong to a superfamily of widely varying structural complexity between mitochondrial and bacterial members of this family. over the last few years, considerable information from this and other laboratories accumulated also on archaeal respiratory chains and their terminal oxidases. in the following, ... | 1996 | 8639327 |
| 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 |
| the unique dna topology and dna topoisomerases of hyperthermophilic archaea. | hyperthermophilic archaea exhibit a unique pattern of dna topoisomerase activities. they have a peculiar enzyme, reverse gyrase, which introduces positive superturns into dna at the expense of atp. this enzyme has been found in all hyperthermophiles tested so far (including bacteria) but never in mesophiles. reverse gyrases are formed by the association of a helicase-like domain and a 5'-type 1 dna topoisomerase. these two domains might be located on the same polypeptide. however, in the methano ... | 1996 | 8639331 |
| general vectors for archaeal hyperthermophiles: strategies based on a mobile intron and a plasmid. | although there are currently no cloning and expression vectors available for archaeal hyperthermophiles, small cryptic plasmids have been characterized for these organisms as well as viruses and introns capable of spreading between cells. below, we review the recent progress in adapting these genetic elements as vectors for pyrococcus furiosus and sulfolobus acidocaldarius. an efficient and reliable transformation procedure is described for both organisms. the potential of the mobile intron from ... | 1996 | 8639332 |
| the pressure-dependence of two beta-glucosidases with respect to their thermostability. | a comparative study of temperature and pressure effects were carried out by using two homologous enzymes exhibiting different thermostability and oligomery: almond beta-glucosidase and sulfolobus solfataricus beta-glucosidase. both the activity and stability were studied using an in-house built bioreactor allowing injection, stirring, sampling and on-line spectrophometric monitoring with retention of pressure up to 2.5 kbar and temperature control possible up to 150 degrees c. almond beta-glucos ... | 1996 | 8645739 |
| industrial-scale production and rapid purification of an archaeal beta-glycosidase expressed in saccharomyces cerevisiae. | the application of enzymes isolated from extreme thermophiles in biotechnological processes is hampered by their unconventional fermentation conditions. the expression, in mesophilic hosts, of genes encoding for thermophilic proteins enables these difficulties to be overcome and permits the production of enzymes in high yield by using conventional fermentation plants and an efficient enzyme purification utilizing heat precipitation of host proteins. the beta-glycosidase gene from sulfolobus solf ... | 1995 | 8573288 |
| two different respiratory rieske proteins are expressed in the extreme thermoacidophilic crenarchaeon sulfolobus acidocaldarius: cloning and sequencing of their genes. | we have isolated two genes encoding rieske iron sulfur proteins from the genomic dna of the thermoacidophilic crenarchaeon sulfolobus acidocaldarius (dsm 639). one of the genes, named soxl, codes for the previously isolated novel rieske-i protein. the second gene (soxf) 121 codes for the rieske-ii protein associated with the second terminal oxidase of sulfolobus. both proteins exhibit only 24% identical residues. the rieske-i protein shows a number of unusual features. (i) the distance between t ... | 1996 | 8654586 |
| exchange of genetic markers at extremely high temperatures in the archaeon sulfolobus acidocaldarius. | when cells of two auxotrophic mutants of sulfolobus acidocaldarius are mixed and incubated on solid medium, they form stable genetic recombinants which can be selected, enumerated, and characterized. any of a variety of auxotrophic markers can recombine with each other, and the phenomenon has been observed at temperatures of up to 84 degrees c. the ability to exchange and recombine chromosomal markers appears to be an intrinsic property of s. acidocaldarius strains. it occurs between two cell li ... | 1996 | 8655500 |
| differential antibiotic sensitivity determined by the large ribosomal subunit in thermophilic archaea. | hybrid ribosomes obtained by mixing the ribosomal subunits of the extremely thermophilic archaea sulfolobus solfataricus and desulfurococcus mobilis were tested for their sensitivity to selected antibiotics. it is shown that structural differences in the large ribosomal subunits determine qualitatively and quantitatively the patterns of response to alpha-sarcin and paromomycin in these species. | 1996 | 8655531 |
| complementation of a pgk deletion mutation in saccharomyces cerevisiae with expression of the phosphoglycerate-kinase gene from the hyperthermophilic archaeon sulfolobus solfataricus. | the gene encoding phosphoglycerate kinase (pgk) from the archaeon sulfolobus solfataricus, an organism growing optimally at 87 degrees c, was inserted into a yeast expression vector under the control of the galactose-inducible gal1 yeast promoter. this vector was then transformed into a pgk::trp1 yeast mutant, a strain inhibited for growth on galactose or glucose due to its lack of pgk enzyme. slow-growing transformants were obtained on galactose plates at 37 degrees c, but not 28 degrees c. the ... | 1996 | 8662201 |
| reca-like genes from three archaean species with putative protein products similar to rad51 and dmc1 proteins of the yeast saccharomyces cerevisiae. | the process of homologous recombination has been documented in bacterial and eucaryotic organisms. the escherichia coli reca and saccharomyces cerevisiae rad51 proteins are the archetypal members of two related families of proteins that play a central role in this process. using the pcr process primed by degenerate oligonucleotides designed to encode regions of the proteins showing the greatest degree of identity, we examined dna from three organisms of a third phylogenetically divergent group, ... | 1996 | 8668545 |
| isocitrate dehydrogenases from haloferax volcanii and sulfolobus solfataricus: enzyme purification, characterisation and n-terminal sequence. | the isocitrate dehydrogenases from the extremely halophilic archaeon, haloferax volcanii, and from the hyperthermophilic archaeon, sulfolobus solfataricus, have been purified to electrophoretic homogeneity. the purified enzymes have been characterised with respect to their cofactor specificities, subunit compositions and their salt and thermal stabilities. n-terminal amino acid sequences have been determined for both enzymes, and multiple alignments with sequences of bacterial and eukaryotic iso ... | 1995 | 8593959 |
| archaeal elongation factor 1 beta is a dimer. primary structure, molecular and biochemical properties. | the elongation factor 1 beta (ef-1 beta), that in eukarya and archaea promotes the replacement of gdp by gtp on the elongation factor 1 alpha x gdp complex, was purified to homogeneity from the thermoacidophilic archaeon sulfolobus solfataricus (ssef-1 beta). its primary structure was established by sequenced edman degradation of the entire protein or its proteolytic peptides. the molecular weight of ssef-1 beta was estimated as about 10000 or 20000 under denaturing or native conditions respecti ... | 1996 | 8652615 |
| isolation, characterization and crystallization of an iron-superoxide dismutase from the crenarchaeon sulfolobus acidocaldarius. | an iron containing superoxide dismutase from the cytosol of the thermoacidophilic crenarchaeon sulfolobus acidocaldarius (dsm 639) has been purified to electrophoretic homogeneity. it comprises at least 11% of the cytosolic protein. the isolated protein consists of two identical subunits with an apparent molecular mass of 22.4 kda. it contains one iron atom per dimer. the protein shows the typical epr spectrum of a s = 3/2, rhombic high-spin iron center. it is extremely resistant against thermal ... | 1996 | 8674972 |
| the sulfolobus solfataricus p2 genome project. | over 800 kbp of the 3-mbp genome of sulfolobus solfataricus have been sequenced to date. our approach is to sequence subclones of mapped cosmids, followed by sequencing directly on cosmid templates with custom primers. using a prototype automated system for genome-scale analysis, known as magpie, along with other tools, we have discovered one open reading frame of at least 100 amino acids per kbp of sequence, and have been able to associate 50% of these with known genes through database searches ... | 1996 | 8682213 |
| functional base-pairing interaction between highly conserved elements of u3 small nucleolar rna and the small ribosomal subunit rna. | the u3 nucleolar rna has a remarkably wide phyletic distribution extending from the eukarya to the archaea. it functions in maturation of the small subunit (ssu) rrna through a mechanism which is as yet unknown but which involves base-pairing with pre-rrna. the most conserved part of u3 is within 30 nucleotides of the 5' end, but as yet no function for this domain has been proposed. elements within this domain are complementary to highly conserved sequences in the ssu rrna which, in the mature f ... | 1996 | 8683571 |
| complete nucleotide sequence of the sulfolobus islandicus multicopy plasmid prn1. | the complete sequence of the 5350-bp plasmid prn1 from the crenarchaeote sulfolobus islandicus has been determined. this plasmid is the first to be sequenced from this group of thermoacidophilic archaebacteria (archaea) and its high copy number and wide host range make it a good candidate for a cloning vector. prn1 contains several open reading frames, including one that spans over half the plasmid and has significant similarity to the helicase domain of viral primase proteins. directly upstream ... | 1996 | 8700967 |
| conversion of product specificity of archaebacterial geranylgeranyl-diphosphate synthase. identification of essential amino acid residues for chain length determination of prenyltransferase reaction. | prenyltransferases catalyze the consecutive condensation of isopentenyl diphosphate with allylic diphosphates to produce prenyl diphosphates whose chain lengths are absolutely determined by each enzyme. to investigate the mechanism of the consecutive reaction and the determination of the ultimate chain length, a random mutational approach was planned. a geranylgeranyl-diphosphate synthase gene from sulfolobus acidocaldarius was randomly mutagenized by nano2 treatment to construct a library of mu ... | 1996 | 8702542 |
| domain organization and dna-induced conformational changes of an archaeal family b dna polymerase. | family b dna polymerase from the thermoacidophilic archaeon sulfolobus solfataricus (sso dna pol) is a monomer of about 100 kda with two associated catalytic functions: 3'-5' exonuclease and dna polymerase activities. the structure of this enzyme in the free and dna-bound states was probed by limited proteolysis and fluorescence spectroscopy measurements. the results of partial trypsin proteolysis experiments on the recombinant sso dna pol pinpointed three major sites of protease sensitivity: ne ... | 1996 | 8703921 |
| adaptive response of the archaeon sulfolobus acidocaldarius bc65 to phosphate starvation. | the adaptive response of the archaeon sulfolobus acidocaldarius bc65 to phosphate starvation was studied. when cells were subjected to phosphate limitation, their growth was affected. in addition, the levels of synthesis and/or the degree of phosphorylation of several proteins changed, as detected by two-dimensional nonequilibrium ph gradient electrophoresis of cells labelled in vivo with [35s]methionine and [35s]cysteine, or h3 32po4. after another growth-restricting treatment, a heat shock, a ... | 1996 | 8704993 |
| nucleic acid binding properties of a helix stabilising nucleoid protein from the thermoacidophilic archaeon sulfolobus acidocaldarius that condenses dna into compact structures. | helix stabilising nucleoid protein (hsnp-c') from an acidothermophilic archaeon sulfolobus acidocaldarius has been characterised with respect to interaction with nucleic acids by gel retardation assay, binding to nucleic acid columns, fluorescence titrations and electron microscopy. the protein exists in solution as very large multimeric aggregates as indicated by cross-linking studies. the protein binds strongly and co-operatively to double stranded dna. electron microscopy of the complexes of ... | 1995 | 8714217 |
| preribosomal rna processing in archaea: characterization of the rnp endonuclease mediated processing of precursor 16s rrna in the thermoacidophile sulfolobus acidocaldarius. | the hyperthermophilic archaeon sulfolobus acidocaldarius uses a novel rna-containing endonuclease to excise and mature 16s rrna from the precursor (pre) rrna transcript. a cell-free processing system has been developed using an in vitro transcribed rna substrate containing the entire 144 nucleotide 5' external transcribed spacer (5'ets) and the first 72 nucleotides of 16s rrna. the cell-free extract cleaves in the 5'ets at positions -99, -31, and +1 (i.e., the 5'ets-16s junction). these position ... | 1995 | 8721997 |
| intercellular mobility and homing of an archaeal rdna intron confers a selective advantage over intron- cells of sulfolobus acidocaldarius. | some intron-containing rrna genes of archaea encode homing-type endonucleases, which facilitate intron insertion at homologous sites in intron- alleles. these archaeal rrna genes, in contrast to their eukaryotic counterparts, are present in single copies per cell, which precludes intron homing within one cell. however, given the highly conserved nature of the sequences flanking the intron, homing may occur in intron- rrna genes of other archaeal cells. to test whether this occurs, the intron-con ... | 1995 | 8618886 |
| equilibrium dna binding of sac7d protein from the hyperthermophile sulfolobus acidocaldarius: fluorescence and circular dichroism studies. | the thermodynamics of the binding of the sac7d protein of sulfolobus acidocaldarius to double-stranded dna has been characterized using spectroscopic signals arising from both the protein and the dna. ligand binding density function analysis has been used to demonstrate that the fractional change in protein intrinsic tryptophan fluorescence quenching that occurs upon dna binding is equal to the fraction of protein bound. reverse titration data have been fit directly to the mcghee-von hippel mode ... | 1996 | 8672437 |
| phylogenetic analysis of carbamoylphosphate synthetase genes: complex evolutionary history includes an internal duplication within a gene which can root the tree of life. | carbamoylphosphate synthetase (cps) catalyzes the first committed step in pyrimidine biosynthesis, arginine biosynthesis, or the urea cycle. organisms may contain either one generalized or two specific cps enzymes, and these enzymes may be heterodimeric (encoded by linked or unlinked genes), monomeric, or part of a multifunctional protein. in order to help elucidate the evolution of cps, we have performed a comprehensive phylogenetic analysis using the 21 available complete cps sequences, includ ... | 1996 | 8752005 |
| characterisation of glucose transport in the hyperthermophilic archaeon sulfolobus solfataricus. | sulfolobus solfiataricus is a hyperthermophilic archaeon growing at 80 degrees c, ph 3. the glucose transport system of this organism has been characterised kinetically at this temperature and ph using 2-deoxy-d-glucose: the sugar analogue is transported into the cells with a km = 1.8 +/- 0.3 microm and a vmax = 3.6 +/- 0.1 nmol min(-1) (mg protein)(-1), with an intracellular accumulation of up to 200-fold over the extracellular concentration. transport was significantly reduced at ph 5. inhibit ... | 1996 | 8674548 |
| uracil phosphoribosyltransferase from the extreme thermoacidophilic archaebacterium sulfolobus shibatae is an allosteric enzyme, activated by gtp and inhibited by ctp. | uracil phosphoribosyltransferase, which catalyses the formation of ump and pyrophosphate from uracil and 5-phosphoribosyl alpha-1-pyrophosphate (prpp), was partly purified from the extreme thermophilic archaebacterium sulfolobus shibatae. the enzyme required divalent metal ions for activity and it showed the highest activity at ph 6.4. the specific activity of the enzyme was 50-times higher at 95 degrees c than at 37 degrees c, but the functional half-life was short at 95 degrees c. the activity ... | 1996 | 8765224 |
| how to make my blood boil. | two recent papers comparing the structure of a hyperthermophilic protein with its mesophilic counterpart both conclude that large networks of ion-pairs are important for hyperthermostability. how and why is not yet clear. | 1995 | 8747452 |
| methionine aminopeptidase-1: the map of the mitochondrion? | | 1996 | 8772380 |
| extremely thermophilic and thermostable 5'-methylthioadenosine phosphorylase from the archaeon sulfolobus solfataricus. gene cloning and amino acid sequence determination. | a gene encoding an extremely thermophilic and thermostable 5'-methylthioadenosine phosphorylase was cloned from the archaeon sulfolobus solfataricus. two degenerate oligodeoxyribonucleotide probes synthesized on the basis of the n-terminal amino acid sequence of the protein were used to screen a genomic library of s. solfataricus cloned into the pgem7zf(+) vector. the dna fragment of 2118 bp containing the 5'-methylthioadenosine phosphorylase gene was sequenced. the open reading frame comprises ... | 1996 | 8774706 |
| thermostable dna polymerases. | | 1996 | 8791630 |
| interfacial air/water proton conduction from long distances by sulfolobus solfataricus archaeal bolaform lipids. | the stability, structural organization, and the ability to transfer protons long distances have been investigated in monolayers formed from archael bolaform lipids at the air/water interface. the lipids employed were the fractions gror2gro (r represents an acyl group with variable chain length typically consisting of 0-4 cyclopentane rings and 40 isoprenoid residues) and gror2gronon-ol (non-ol represents nonitol) extracted from sulfolobus solfataricus by hydrolysis of the cytoplasmic membrane. g ... | 1996 | 8797852 |
| molecular cloning, sequencing, and heterologous expression of a novel zinc-containing ferredoxin gene from a thermoacidophilic archaeon sulfolobus sp. strain 7. | the gene encoding a novel zinc-containing ferredoxin from a hyperthermophilic and acidophilic archaeon (archaebacterium) sulfolobus sp. strain 7 was cloned and sequenced. the dna sequence predicts a 103 residue protein after removal of n-terminal methionine, which is in good agreement with the results of the protein analysis. surprisingly, the residues responsible for binding a zinc atom were conserved among three other thermoacidophilic archaea. a common sequence stretch vxgxhxghx8-17pxxlgxhgtx ... | 1996 | 8753789 |
| adenylate kinase from sulfolobus acidocaldarius: expression in escherichia coli and characterization by fourier transform infrared spectroscopy. | adenylate kinase from the extremely thermoacidophilic archaeon sulfolobus acidocaldarius has been overexpressed in escherichia coli. the highly purified enzyme was characterized by fourier transform infrared spectroscopy (ftir). analysis of ftir spectra and estimation of secondary structure revealed a global protein structure similar to that of other adenylate kinases. thermal unfolding of the protein with an estimated tm value near 90 degrees c is irreversible due to protein aggregation. the en ... | 1996 | 8806756 |
| cca-adding enzymes and poly(a) polymerases are all members of the same nucleotidyltransferase superfamily: characterization of the cca-adding enzyme from the archaeal hyperthermophile sulfolobus shibatae. | we describe the purification, cloning, and characterization of the cca-adding enzyme [atp(ctp):trna nucleotidyl transferase] from the thermophilic archaebacterium, sulfolobus shibatae. characterization of an archaeal cca-adding enzyme provides formal proof that the cca-adding activity is present in all three contemporary kingdoms. antibodies raised against recombinant, expressed sulfolobus cca-adding enzyme reacted specifically with the 48-kda protein and fully depleted all cca-adding activity f ... | 1996 | 8809016 |
| identification and characterization of geranylgeraniol kinase and geranylgeranyl phosphate kinase from the archaebacterium sulfolobus acidocaldarius. | geranylgeranyl diphosphate is an important precursor of archaebacterial ether-linked lipids, and it has been thought that all of this compound is "de novo" synthesized by geranylgeranyl diphosphate synthase. we studied the phosphorylation of geranylgeraniol, which seems to be related to the salvage pathway of biosynthesis of archaebacterial ether-linked lipids, in the archaebacterium sulfolobus acidocaldarius. activities of geranylgeraniol kinase and geranylgeranyl phosphate kinase were detected ... | 1996 | 8830051 |
| novel zinc-binding centre in thermoacidophilic archaeal ferredoxins. | | 1996 | 8836097 |
| uracil-dna glycosylase activities in hyperthermophilic micro-organisms. | hyperthermophiles exist in conditions which present an increased threat to the informational integrity of their dna, particularly by hydrolytic damage. as in mesophilic organisms, specific activities must exist to restore and protect this template function of dna. in this study we have demonstrated the presence of thermally stable uracil-dna glycosylase activities in seven hyperthermophiles; one bacterial: thermotoga maritima, and six archaeal: sulfolobus solfataricus, sulfolobus shibatae, sulfo ... | 1996 | 8837481 |
| resonance raman spectroscopy of the integral quinol oxidase complex of sulfolobus acidocaldarius. | the integral quinol oxidase complex of sulfolobus acidocaldarius (dsm 639) was investigated by resonance raman spectroscopy. the complex includes four heme a groups which constitute two functional entities, a587 and aa3, containing two low-spin hemes and a low-spin as well as a high-spin heme, respectively. rr spectra were obtained from the fully oxidized and fully reduced states of the complex using different excitation wavelengths in the soret band region in order to disentangle the contributi ... | 1996 | 8841122 |
| functional and structural properties of the homogeneous beta-glycosidase from the extreme thermoacidophilic archaeon sulfolobus solfataricus expressed in saccharomyces cerevisiae. | a protein with beta-glycosidase activity from sulfolobus solfataricus (s beta gly) was expressed in the yeast saccharomyces cerevisiae. the purification procedure was made fast and easy by employing a single chromatographic step. after 5.8-fold purification, the cell extract gave a homogeneous enzyme at 166 u/mg. the recombinant enzyme was functionally and structurally similar to the wild-type enzyme. kinetic experiments showed the same wide substrate specificity; in fact, the expressed enzyme h ... | 1996 | 8860656 |
| a novel amidohydrolase gene from bacillus subtilis cloning: dna-sequence analysis and map position of amhx. | the nucleotide sequence of a new bacillus subtilis gene (amhx) was determined that encodes a protein (amhx) with strong sequence identity to amidohydrolases from both plant and bacterial species and a carboxypeptidase from the archaeon sulfolobus sulfataricus. the amhx gene encodes a hydrophilic polypeptide of 383 amino acids with a molecular mass of 41.5 kda. the amhx gene was overexpressed in e. coli by using the t7 rna polymerase/promoter system and the transcription initiation sites for the ... | 1996 | 8768514 |
| purification and characterization of nadh oxidase from the archaea sulfolobus acidocaldarius and sulfolobus solfataricus. | the enzyme nadh oxidase (ec 1.6.99.3) has been isolated from the two thermoacidophilic archaea sulfolobus acidocaldarius and sulfolobus solfataricus and characterized. in both organisms the enzyme oxidizes specifically beta-nadh in the presence of molecular oxygen and requires the presence of a flavin cofactor, showing a high specificity for fad. a stoicheiometric amount of hydrogen peroxide to nadh is formed as the end product of the reaction, indicating that both enzymes are two-electron donor ... | 1996 | 8867896 |
| identification of a dinb/umuc homolog in the archeon sulfolobus solfataricus. | to date, eight closely related homologs of the escherichia coli umuc protein have been identified. all of these homologs appear to play critical roles in damage-inducible mutagenesis in enterobacteriaceae. recently, a distantly related umuc-homolog, dinb, has also been identified in e. coli. using the polymerase chain reaction together with degenerate primers designed against conserved regions found in umuc-like proteins, we have identified a new member of the umuc-superfamily in the archeon sul ... | 1996 | 8876701 |
| the response of selected members of the archaea to the gram stain. | archaea possess a broader range of cell envelope structural formats than eubacteria and their cell walls do not contain peptidoglycan. some archaea have only a single s-layer as their cell wall (e.g. methanococcus jannaschii and sulfolobus acidocaldarius), whereas others have multiple layers (e.g. methanospirillum hungatei). sometimes there can also be a high proportion of tetraether lipids in membranes to make the envelope more resilient to environmental stress (e.g. methanococcus jannaschii an ... | 1996 | 8885405 |
| 2.0 a structure of indole-3-glycerol phosphate synthase from the hyperthermophile sulfolobus solfataricus: possible determinants of protein stability. | recent efforts to understand the basis of protein stability have focused attention on comparative studies of proteins from hyperthermophilic and mesophilic organisms. most work to date has been on either oligomeric enzymes or monomers comprising more than one domain. such studies are hampered by the need to distinguish between stabilizing interactions acting between subunits or domains from those acting within domains. in order to simplify the search for determinants of protein stability we have ... | 1995 | 8747456 |
| comparison of a beta-glucosidase and a beta-mannosidase from the hyperthermophilic archaeon pyrococcus furiosus. purification, characterization, gene cloning, and sequence analysis. | two distinct exo-acting, beta-specific glycosyl hydrolases were purified to homogeneity from crude cell extracts of the hyperthermophilic archaeon pyrococcus furiosus: a beta-glucosidase, corresponding to the one previously purified by kengen et al. (kengen, s. w. m., luesink, e. j., stams, a. j. m., and zehnder, a. j. b. (1993) eur. j. biochem. 213, 305-312), and a beta-mannosidase. the beta-mannosidase and beta-glucosidase genes were isolated from a genomic library by expression screening. the ... | 1996 | 8798600 |
| expression in escherichia coli of thermostable elongation factor 1 alpha from the archaeon sulfolobus solfataricus. | the elongation factor 1 alpha from the archaeon sulfolobus solfataricus (ssef-1 alpha) was expressed in escherichia coli and purified. the ssef-1 alpha gene was amplified by pcr and cloned in the ndel site of the pt7-7 expression vector, under the control of the promoter of t7 rna polymerase. upon induction with isopropyl beta-d-thiogalactopyranoside, the recombinant ssef-1 alpha (recssef-1 alpha) was purified from the e. coli s-100 extract by a two-step procedure. from 1 litre of cell culture, ... | 1996 | 8867895 |
| organizational characteristics and information content of an archaeal genome: 156 kb of sequence from sulfolobus solfataricus p2. | we have initiated a project to sequence the 3 mbp genome of the thermoacidophilic archaebacterium sulfolobus solfataricus p2. cosmids were selected from a provisional set of minimally overlapping clones, subcloned in puc18, and sequenced using a hybrid (random plus directed) strategy to give two blocks of contiguous unique sequence, respectively, 100,389 and 56,105 bp. these two contigs contain a total of 163 open reading frames (orfs) in 26-29 putative operons; 56 orfs could be identified with ... | 1996 | 8899719 |
| effect of physical constraints on the mechanisms of membrane fusion: bolaform lipid vesicles as model systems. | bolaform lipid vesicles were used to study the effect of physical constraints on membrane fusion. in these vesicles the membrane is organized in a single monolayer, because of the presence of covalent bonds in its middle plane. therefore, the formation of fusion intermediates is subject to higher energy barriers and greater geometrical constraints than is usual in bilayer membranes. bolaform lipids were extracted from the thermophilic archaeon sulfolobus solfataricus. these lipids can be divided ... | 1996 | 8889155 |
| role of cytochrome b562 in the archaeal aerobic respiratory chain of sulfolobus sp. strain 7. | the role of cytochrome b562, a fragile constituent of the respiratory terminal oxidase supercomplex of the thermoacidophilic archaeon, sulfolobus sp. strain 7, was investigated spectroscopically in the membrane-bound state. cytochrome b562 did not react with co or cyanide in the membrane-bound state, while it was irreversibly modified to a co-reactive form (b59) upon solubilization in the presence of cholate and licl. cyanide titration analyses with the succinate-reduced membrane suggested that ... | 1996 | 8900071 |
| purification and characterization of new trehalose-producing enzymes isolated from the hyperthermophilic archae, sulfolobus solfataricus km1. | amylolytic activity that converts soluble starch to alpha, alpha-trehalose (trehalose), was found in the cell homogenate of the hyperthermophilic acidophilic archae, sulfolobus solfataricus km1. deae chromatography of the homogenate as well as other new reliable assay methods showed two enzymes to be essential for this activity. these enzymes, a glycosyltransferase and an amylase, were purified to homogeneity and characterized. their molecular masses were 76 kda and 61 kda and activities were ma ... | 1996 | 8901122 |
| 2-oxoacid:ferredoxin oxidoreductase from the thermoacidophilic archaeon, sulfolobus sp. strain 7. | the purified 2-oxoacid:ferredoxin oxidoreductase of a thermoacidophilic and aerobic crenarchaeote, sulfolobus sp. strain 7, consists of 70-kda alpha and 37-kda beta subunits, and contains one thiamine pyrophosphate (tpp), one [4fe-4s]2+.1+ cluster, and two magnesium atoms per alpha beta structure. it exhibits a broad substrate specificity toward 2-oxoacids such as 2-oxoglutarate, 2-oxobutyrate, and pyruvate. the gene encoding the archaeal oxidoreductase was cloned, and the two open reading frame ... | 1996 | 8902625 |
| an aspartate aminotransferase from an extremely thermophilic bacterium, thermus thermophilus hb8. | the aspartate aminotransferase gene (aspat, ec 2.6.1.1) of an extremely thermophilic bacterium, thermus thermophilus hb8, was cloned and sequenced, and its gene product was overproduced. the purified t. thermophilus aspat was stable up to about 80 degrees c at neutral ph. t. thermophilus aspat was strictly specific for acidic amino acid substrates, such as aspartate, glutamate, and the respective keto acids. the gene coding for t. thermophilus aspat showed that it comprised 1,155 bp with a high ... | 1996 | 8907187 |
| redox-linked ionization of sulredoxin, an archaeal rieske-type [2fe-2s] protein from sulfolobus sp. strain 7. | "sulredoxin" of sulfolobus sp. strain 7 is an archaeal soluble rieske-type [2fe-2s] protein and was initially characterized by several spectroscopic techniques (iwasaki, t., isogai, t., iizuka, t. , and oshima, t. (1995) j. bacteriol. 177, 2576-2582). it appears to have tightly linked ionization affecting the redox properties of the protein, which is characteristic of the rieske fes proteins found as part of the respiratory chain. sulredoxin had an em(low ph) value of +188 +/- 9 mv, and the slop ... | 1996 | 8910356 |
| protein-encoding genes in the sulfothermophilic archaea sulfolobus and pyrococcus. | a number of unrelated protein-encoding genes from sulfothermophilic archaea, sulfolobus acidocaldarius, sulfolobus solfataricus, pyrococcus furiosus and pyrococcus woesei, has been analyzed. in the sulfolobus genus, the content of a + t is significantly higher than that of c + g and the base usage follows the order, a > t > g > c. in pyrococcus, the a + t content is also higher than that of c + g, but with lower values; in the order of base usage, g precedes t. the codon usage of these sulfother ... | 1996 | 8918227 |
| temperature-induced denaturation of beta-glycosidase from the archaeon sulfolobus solfataricus. | the beta-glycosidase isolated from the extreme thermophilic archaeon sulfolobus solfataricus, grown at 87 degrees c, is a tetrameric protein with a molecular mass of 240 kda. this enzyme is barely active at 30 degrees c and has optimal activity, over 95 degrees c, at ph 6.5. its thermal stability was investigated at ph 10.1 and 10.6 by means of functional studies, circular dichroism and differential scanning calorimetry. there was no evidence of thermal activation of the enzyme and the temperatu ... | 1996 | 8889813 |
| the dna polymerase-encoding gene from a thermoacidophilic archaeon sulfolobus acidocaldarius. | we have cloned, sequenced and characterized the gene encoding a dna polymerase from the thermoacidophilic archaeon sulfolobus acidocaldarius (sac). the putative transcription promoter and terminator elements, as well as a potential ribosome-binding site (rbs), have been identified in the flanking regions. one large open reading frame (orf) found in the sequenced portion of the sac genome encodes a protein of 875 amino acids (aa). all conserved motifs characteristic of family b of dna polymerases ... | 1996 | 8921881 |
| the crystal structure of indole-3-glycerol phosphate synthase from the hyperthermophilic archaeon sulfolobus solfataricus in three different crystal forms: effects of ionic strength. | indole-3-glycerol phosphate synthase from the hyperthermophilic archaeon sulfolobus solfataricus is a monomeric enzyme with the common (beta/alpha)8-fold. recently, its three-dimensional structure was solved in an orthorhombic crystal form, grown by using 1.3 m ammonium sulfate as precipitating agent. here we describe the x-ray structure analysis of two new crystal forms of this enzyme that were obtained at medium and low ionic strength, respectively. hexagonal crystals with space group p3(1)21 ... | 1996 | 8893859 |
| sulfolobus hakonensis sp. nov., a novel species of acidothermophilic archaeon. | we characterized a microbial strain that was isolated from a hot spring at a geothermal area in hakone, japan. this isolate, whose lobed-shaped cells were about 1.0 micron in diameter, was a facultative chemolitho-autotroph that required aerobic conditions for growth. the optimum ph was 3.0 (ph range, 1.0 to 4.0), and the optimum temperature was 70 degrees c (temperature range, 50 to 80 degrees c). lithotrophically, this strain grew on elemental sulfur and reduced sulfur compounds. the g+c conte ... | 1996 | 8934897 |
| transformation of the extremely thermoacidophilic archaeon sulfolobus solfataricus via a self-spreading vector. | we describe a transformation system for extremely thermophilic archaea of the genus sulfolobus in the kingdom crenarchaeota. we have constructed in vitro a recombinant derivative of the recently described conjugative plasmid pnob8, containing a beta-galactosidase gene downstream of a strong promotor. transformation of a beta-galactosidase negative mutant of sulfolobus solfataricus with this construct resulted in its spreading through the culture containing the primary transformants and in effici ... | 1996 | 8935654 |
| a putative signal recognition particle receptor alpha subunit (sr alpha) homologue is expressed in the hyperthermophilic crenarchaeon sulfolobus acidocaldarius. | a 1.64 kb genomic dna sequence from the hyperthermophilic crenarchaeon sulfolobus acidocaldarius is composed of two adjacent genes. the first functionally unassigned open reading frame (orf-1) comprises 450 base pairs. the second 1.1 kb large open reading frame encodes the putative signal recognition particle receptor alpha subunit (sr alpha). both genes are expressed under the heterotrophic growth conditions of the organism. the main transcript of orf-1 appears as a monocistronic rna in norther ... | 1996 | 8935656 |
| bacteria breakfast. | | 1996 | 8959404 |
| an archaebacterial homolog of pelota, a meiotic cell division protein in eukaryotes. | an open reading frame (pela) specifying a homolog of pelota and dom34, proteins required for meiotic cell division in drosophila melanogaster and saccharomyces cerevisiae, respectively, has been cloned, sequenced and identified from the archaebacterium sulfolobus solfataricus. the s. solfataricus pela protein is about 20% identical with pelota, dom34 and the hypothetical protein r74.6 of caenorhabditis elegans. the presence of a pelota homolog in archaebacteria implies that the meiotic functions ... | 1996 | 8900058 |
| cloning and sequencing of a gene encoding 16s ribosomal rna from a novel hyperthermophilic archaebacterium nc12. | a hyperthermophile nc12 was newly isolated from noboribetsu hot spring. to characterize this organism, a gene coding for 16s rrna was cloned and sequenced. the 16s rrna sequence from nc12 shows the highest similarity with those from pyrodictium occultum and desulfurococcus mobilis among the sequences in the database, indicating that nc12 belongs to a cluster of extreme thermophiles (crenarchaeota) in the archaeal domain. however, since the highest identity score was only 91.2%, it is suggested t ... | 1996 | 8973365 |
| glutamate-1-semialdehyde aminotransferase from sulfolobus solfataricus. | glutamate-1-semialdehyde aminotransferase (gsa-at) from the extremely thermophilic bacterium sulfolobus solfataricus has been purified to homogeneity and characterized. gsa-at is the last enzyme in the c5 pathway for the conversion of glutamate into the tetrapyrrole precursor delta-aminolaevulinate (ala) in plants, algae and several bacteria. the active form of gsa-at from s. solfataricus seems to be a homodimer with a molecular mass of 87 kda. the absorption spectrum of the purified aminotransf ... | 1996 | 8973563 |
| reverse gyrase gene from sulfolobus shibatae b12: gene structure, transcription unit and comparative sequence analysis of the two domains. | we cloned and sequenced a dna fragment from the thermophilic archaeal strain sulfolobus shibatae b12 that includes the gene topr encoding the reverse gyrase. the rna of the reverse gyrase gene was characterized indicating that the topr gene is fully functional in vivo. we showed by primer extension analysis that transcription of topr initiates 28 bp downstream from a consensus a-box promoter. in order to understand how this particular type i dna topoisomerase introduces positive superturns into ... | 1996 | 8972852 |
| hyperthermophile protein folding thermodynamics: differential scanning calorimetry and chemical denaturation of sac7d. | recombinant sac7d protein from the thermoacidophile sulfolobus acidocaldarius is shown to be stable towards acid, thermal and chemical denaturation. the protein maintains a compact native fold between ph 0 and 10 in 0.3 m kcl and 25 degrees c as indicated by near and far uv circular dichroism spectra. thermal unfolding followed by differential scanning calorimetry (dsc) occurs as a reversible, two-state transition from ph 0 to 10, with a maximal tm of 90.7 degrees c between ph 5 and 9. at ph 0 t ... | 1996 | 8980686 |
| bioenergetics of the archaebacterium sulfolobus. | archaea are forming one of the three kingdoms defining the universal phylogenetic tree of living organisms. within itself this kingdom is heterogenous regarding the mechanisms for deriving energy from the environment for support of cellular functions. these comprise fermentative and chemolithotrophic pathways as well as light driven and respiratory energy conservation. due to their extreme growth conditions access to the molecular machineries of energy transduction in archaea can be experimental ... | 1996 | 8982385 |
| kow: a novel motif linking a bacterial transcription factor with ribosomal proteins. | | 1996 | 8987397 |
| gene cloning and expression of new trehalose-producing enzymes from the hyperthermophilic archaeum sulfolobus solfataricus km1. | the genes encoding for trehalose-producing enzymes, a glycosyl-trehalose-producing enzyme (glycosyltransferase) and a gylcosyl-trehalose-hydrolyzing enzyme (alpha-amylase), from sulfolobus solfataricus km1 were cloned and expressed in e. coli. the nucleotide sequence of the glycosyltransferase gene and the alpha-amylase gene indicated proteins with lengths of 728 and 558 amino acids and molecular masses of 86-kda and 65-kda, respectively. regions highly conserved in the alpha-amylase family exis ... | 1996 | 8987868 |
| cloning and sequencing of the gene coding for s-adenosylhomocysteine hydrolase in the thermophilic archaeon sulfolobus solfataricus. | the gene from the thermophilic archaeon sulfolobus solfataricus (ss), encoding the s-adenosylhomocysteine hydrolase (adohcyhd), has been cloned. two degenerate oligodeoxyribonucleotide (oligo) probes, synthesized on the basis of amino acid (aa) sequence of cyanogen bromide-peptide fragments of the purified protein, were used to screen a genomic library of ss cloned into the pgem7zf(+) vector. the adohcyhd gene (adohcyhd) comprises 1254 nucleotides (nt) and encodes a polypeptide of 417 aa with a ... | 1996 | 8921839 |
| identification of two glutamic acid residues essential for catalysis in the beta-glycosidase from the thermoacidophilic archaeon sulfolobus solfataricus. | the sulfolobus solfataricus, strain mt4, beta-glycosidase (ss beta-gly) is a thermophilic member of glycohydrolase family 1. to identify active-site residues, glutamic acids 206 and 387 have been changed to isosteric glutamine by site-directed mutagenesis. mutant proteins have been purified to homogeneity using the schistosoma japonicum glutathione s-transferase (gst) fusion system. the proteolytic cleavage of the chimeric protein with thrombin was only obtainable after the introduction of a mol ... | 1996 | 9010932 |
| novel zinc-containing ferredoxin family in thermoacidophilic archaea. | the dicluster-type ferredoxins from the thermoacidophilic archaea such as thermoplasma acidophilum and sulfolobus sp. are known to contain an unusually long extension of unknown function in the n-terminal region. recent x-ray structural analysis of the sulfolobus ferredoxin has revealed the presence of a novel zinc center, which is coordinated by three histidine ligand residues in the n-terminal region and one aspartate in the ferredoxin core domain. we report here the quantitative metal analyse ... | 1997 | 9013590 |
| expression of sulfolobus solfataricus trpe and trpg genes in e. coli. | the genes trpe and trpg of the hyperthermophilic archaeon sulfolobus solfataricus, encoding the components i and ii of anthranilate synthase, were cloned and co-expressed in escherichia coli. the properties of the recombinant protein were determined and compared to those of the wild type complex. gel filtration chromatography revealed an alpha2beta2 composition. the heteromeric enzyme is fully active above 85 degrees c and can be considered to be an "extremozyme" according to adams et al.[1]. su ... | 1997 | 9016772 |
| molecular and phylogenetic characterization of isopropylmalate dehydrogenase of a thermoacidophilic archaeon, sulfolobus sp. strain 7. | the archaeal leub gene encoding isopropylmalate dehydrogenase of sulfolobus sp. strain 7 was cloned, sequenced, and expressed in escherichia coli. the recombinant sulfolobus sp. enzyme was extremely stable to heat. the substrate and coenzyme specificities of the archaeal enzyme resembled those of the bacterial counterparts. sedimentation equilibrium analysis supported an earlier proposal that the archaeal enzyme is homotetrameric, although the corresponding enzymes studied so far have been repor ... | 1997 | 9023199 |
| properties of truncated forms of the elongation factor 1alpha from the archaeon sulfolobus solfataricus. | two truncated forms of the sulfolobus solfataricus elongation factor 1alpha (ssef-1alpha), corresponding to the putative domains g+m, ss(gm)ef-1alpha, and g, ss(g)ef-1alpha, have been constructed by gene engineering, produced in escherichia coli and purified. neither truncated form was able to sustain poly(phe) synthesis but they were able to bind guanine nucleotides with an affinity much higher with respect to that of the intact factor. however, the difference in the affinity for gdp and gtp be ... | 1997 | 9030774 |
| non-thermal effects of microwaves on proteins: thermophilic enzymes as model system. | two thermophilic and thermostable enzymes, isolated from sulfolobus solfataricus, s-adenosylhomocysteine hydrolase and 5'-methylthioadenosine phosphorylase, were exposed to 10.4 ghz microwave radiation in order to discriminate between thermal and non-thermal microwave effects. the exposure causes a non-thermal, irreversible and time-dependent inactivation of both enzymes; the inactivation rate is related to the energy absorbed and is independent of the enzyme concentration. the influence of salt ... | 1997 | 9037175 |
| perturbation of conformational dynamics, enzymatic activity, and thermostability of beta-glycosidase from archaeon sulfolobus solfataricus by ph and sodium dodecyl sulfate detergent. | the conformational dynamics of beta-glycosidase from sulfolobus solfataricus was investigated by following the emission decay arising from the large number of tryptophanyl residues that are homogeneously dispersed in the primary structure. the fluorescence emission is characterized by a bimodal lifetime distribution, suggesting that the enzyme structure contains rigid and flexible regions, properly located in the macromolecule. the enzyme activity and thermostability appear to be related to the ... | 1997 | 9037713 |
| three extremely thermostable proteins from sulfolobus and a reappraisal of the 'traffic rules'. | three cytosolic enzymes from the extremely thermoacidophilic archaeon sulfolobus acidocaldarius (dsm 639) have been investigated: adenylate kinase, pyrophosphatase and superoxide dismutase. the latter was isolated from s. acidocaldarius cells, the others were heterologically overproduced in escherichia coli. long-term thermostability, flexibility, catalytic activity, and thermal denaturation were investigated by biochemical and physical methods. superoxide dismutase is hyperthermostable over sev ... | 1996 | 8922285 |
| characterization of the reverse gyrase from the hyperthermophilic archaeon pyrococcus furiosus. | the reverse gyrase gene rgy from the hyperthermophilic archaeon pyrococcus furiosus was cloned and sequenced. the gene is 3,642 bp (1,214 amino acids) in length. the deduced amino acid sequence has relatively high similarity to the sequences of the methanococcus jannaschii reverse gyrase (48% overall identity), the sulfolobus acidocaldarius reverse gyrase (41% identity), and the methanopynrus kandleri reverse gyrase (37% identity). the p. furiosus reverse gyrase is a monomeric protein, containin ... | 1997 | 9045834 |
| multitryptophan-fluorescence-emission decay of beta-glycosidase from the extremely thermophilic archaeon sulfolobus solfataricus. | the emission decay of intrinsic fluorescence of the extremely thermophilic beta-glycosidase from sulfolobus solfataricus has been investigated as functions of temperature and of iodide-quencher concentration by frequency-domain fluorometry. this protein contains 68 tryptophans and provides a matrix for correlation of the average spectroscopic behaviour with solvent exposure and local dynamics. at each temperature, the emission is very heterogeneous and interpretable in terms of quasicontinuous b ... | 1997 | 9063445 |
| thermal unfolding of the dna-binding protein sso7d from the hyperthermophile sulfolobus solfataricus. | thermal unfolding of the small hyperthermophilic dna-binding protein sso7d was studied by circular dichroism spectroscopy and differential scanning calorimetry. the unfolding transition can be described by a reversible two state process. maximum stability was observed in the region between ph 4.5 and 7.0 where sso7d unfolds with a melting temperature between 370.8 to 371.9 k and an unfolding enthalpy between 62.9 and 65.4 kcal/mol. the heat capacity differences between the native and the heat de ... | 1996 | 9000635 |
| cloning and sequencing of a cluster of genes encoding novel enzymes of trehalose biosynthesis from thermophilic archaebacterium sulfolobus acidocaldarius. | trehalose biosynthesis genes, trez, trex and trey, encoding maltooligosyltrehalose trehalohydrolase (trez), glycogen debranching enzyme (trex), and maltooligosyltrehalose synthase (trey) have been cloned from the thermophilic archaebacterium sulfolobus acidocaldarius atcc33909. the amino-acid sequences deduced from trez, trex and trey are composed of 556, 713 and 720 amino-acid residues, respectively. trez and trey are 33-40% homologous to the corresponding enzymes from arthrobacter sp. q36. we ... | 1996 | 8980629 |
| the presence of gpi-linked protein(s) in an archaeobacterium, sulfolobus acidocaldarius, closely related to eukaryotes. | gpi-anchored proteins are distributed ubiquitously in eukaryotes, but not in procaryotes. by metabolic-labeling of sulfolobus acidocaldarius cells, 14c-radiolabeled precursors of gpi and caldarchaetidylinositol were incorporated into 120, 143 and 185 kda proteins. the 185 kda protein was specifically solubilized by bacterial phosphatidylinositol-specific phospholipase c. therefore, sulfolobus proved to contain at least one gpi-anchored proteins. | 1997 | 9042356 |
| comparative analysis of embden-meyerhof and entner-doudoroff glycolytic pathways in hyperthermophilic archaea and the bacterium thermotoga. | the embden-meyerhof (em) or entner-doudoroff (ed) pathways of sugar degradation were analyzed in representative species of the hyperthermophilic archaeal genera thermococcus, desulfurococcus, thermoproteus, and sulfolobus, and in the hyperthermophilic (eu)bacterial genus thermotoga. the analyses included (1) determination of 13c-labeling patterns by 1h- and 13c-nmr spectroscopy of fermentation products derived from pyruvate after fermentation of specifically 13c-labeled glucose by cell suspensio ... | 1997 | 9075622 |
| the archaeal soxabcd complex is a proton pump in sulfolobus acidocaldarius. | the thermoacidophilic archaeon sulfolobus acidocaldarius expresses a very unusual quinol oxidase, which contains four heme a redox centers and one copper atom. the enzyme was solubilized with dodecyl maltoside and purified to homogeneity by a combination of hydrophobic interaction and anion exchange chromatography. the oxidase complex consists of four polypeptide subunits with apparent molecular masses of 64, 39, 27, and 14 kda that are encoded by the soxabcd operon (lübben, m., kolmerer, b., an ... | 1997 | 9079667 |
| protein-tyrosine phosphorylation in the archaea. | sulfolobus sulfataricus atcc 35091, haloferax volcanii, and methanosarcina thermophila tm-1, representing the euryarchaeota and crenarchaeota subdomains of the archaea, contain proteins which are phosphorylated on tyrosine. these data raise fundamental questions as to the origin and evolution of tyrosine phosphorylation, a protein modification that is of pivotal importance in the regulation of the physiology of eukaryotic cells. | 1997 | 9079930 |