| structure determination of two new amino acid-containing derivatives of adenosine from trna of thermophilic bacteria and archaea. | two new nucleosides have been identified in unfractionated transfer rna of two thermophilic bacteria, thermodesulfobacterium commune, and thermotoga maritima, six hyperthermophilic archaea, including pyrobaculum islandicum, pyrococcus furiosus and thermococcus sp. and two mesophilic archaea, methanococcus vannielii and methanolobus tindarius. structures were determined primarily by mass spectrometry, as 3-hydroxy-n-[[(9-beta-d-ribofuranosyl-9h-purin-6- yl)amino]carbonyl]norvaline, (hn6a), struct ... | 1992 | 1280806 |
| amplimers with 3'-terminal phosphorothioate linkages resist degradation by vent polymerase and reduce taq polymerase mispriming. | the 3'-->5' exonuclease activity of vent, a thermostable polymerase from thermococcus litoralis, enhances dna replication fidelity but also diverts pcr primers (amplimers) from targeted amplification by degrading their 3' termini. we demonstrate that amplimers with a 3-base 3'-terminal mismatch can be efficiently truncated by vent to prime dna polymerizations that compete with the specific amplification reaction. however, amplimers with phosphorothioate bonds joining their 3'-terminal residues a ... | 1992 | 1335814 |
| a universal method for the direct cloning of pcr amplified nucleic acid. | we have devised a simple, universal cloning strategy that permits the direct ligation of pcr amplified nucleic acid to a compatible vector preparation. the method does not require that special restriction sites or additional sequences be appended onto the amplification primers, nor the use of restriction endonucleases, modifying enzymes, or any purification procedures. this approach takes advantage of the single 3' deoxyadenylate extension that thermus aquaticus, thermus flavus, and thermococcus ... | 1991 | 1367662 |
| nucleotide sequence of the genes encoding the three largest subunits of the dna-dependent rna polymerase from the archaeum thermococcus celer. | | 1992 | 1408768 |
| detection of single base differences using biotinylated nucleotides with very long linker arms. | a simple primer extension method for detecting nucleotide differences is based on the substitution of mobility-shifting analogs for natural nucleotides (1). this technique can detect any single-base difference that might occur including previously unknown mutations or polymorphisms. two technical limitations of the original procedure have now been addressed. first, switching to thermococcus litoralis dna polymerase has eliminated variability believed to be due to the addition of an extra, non-te ... | 1992 | 1408798 |
| proton nmr investigation of the oxidized three-iron clusters in the ferredoxins from the hyperthermophilic archae pyrococcus furiosus and thermococcus litoralis. | the 3fe forms of ferredoxins (fd) from the hyperthermophilic archaebacteria pyrococcus furiosus (pf) and thermococcus litoralis (tl) have been investigated by 1h nmr. a combination of one-dimensional nuclear overhauser and two-dimensional noesy and bond correlation spectroscopy provides the assignment of the aromatic residues, one conserved valine, and the location of the signals for each of the three cysteines coordinated to the clusters. dipolar contacts between the trp 2 and tyr 46 in pf fd a ... | 1992 | 1445925 |
| protein splicing removes intervening sequences in an archaea dna polymerase. | the vent dna polymerase gene from thermococcus litoralis contains two in-frame insertions that must be spliced out to form the mature polymerase. primer extension and cdna pcr revealed no evidence of spliced rna to account for this editing. in contrast, pulse-chase analysis indicated that expression constructs lacking the first insertion produced a protein precursor in escherichia coli that was processed post-translationally to form polymerase and i-tlii, the endonuclease protein that is the pro ... | 1992 | 1475179 |
| intervening sequences in an archaea dna polymerase gene. | the dna polymerase gene from the archaea thermococcus litoralis has been cloned and expressed in escherichia coli. it is split by two intervening sequences (ivss) that form one continuous open reading frame with the three polymerase exons. to our knowledge, neither ivs is similar to previously described introns. however, the deduced amino acid sequences of both ivss are similar to open reading frames present in mobile group i introns. the second ivs (ivs2) encodes an endonuclease, i-tli i, that ... | 1992 | 1608969 |
| posttranscriptional modification of trna in thermophilic archaea (archaebacteria). | nucleoside modification has been studied in unfractionated trna from 11 thermophilic archaea (archaebacteria), including phylogenetically diverse representatives of thermophilic methanogens and sulfur-metabolizing hyperthermophiles which grow optimally in the temperature range of 56 (thermoplasma acidophilum) to 105 degrees c (pyrodictium occultum), and for comparison from the most thermophilic bacterium (eubacterium) known, thermotoga maritima (80 degrees c). nine nucleosides are found to be un ... | 1991 | 1708763 |
| 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 |
| 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 |
| effects of different dna polymerases in ligation-mediated pcr: enhanced genomic sequencing and in vivo footprinting. | we have developed a simplified procedure for the ligation-mediated polymerase chain reaction (lmpcr) using thermococcus litoralis dna polymerase (vent dna polymerase). we show that vent dna polymerase produces correct, blunt-ended primer extension products with substantially higher efficiency than thermus aquaticus (taq) dna polymerase or modified t7 dna polymerase (sequenase). this difference leads to significantly improved genomic sequencing, methylation analysis, and in vivo footprinting with ... | 1992 | 1736283 |
| analysis of mutations using pcr and denaturing gradient gel electrophoresis. | denaturing gradient gel electrophoresis (dgge) separates dna molecules based on primary sequence. under the appropriate conditions, all base pair (bp) substitutions, frame-shifts, and deletions less than about 10 bp can be resolved from the wild type sequence using dgge. polymerase chain reaction (pcr) permits facile amplification of a given region of the genome. we have combined pcr and dgge to: (i) localize mutations in the x-linked human androgen receptor gene. pcr/dgge was used to screen the ... | 1991 | 1748086 |
| nucleotide sequence of the genes encoding the l30, s12 and s7 equivalent ribosomal proteins from the archaeum thermococcus celer. | | 1991 | 1840672 |
| fidelity of thermococcus litoralis dna polymerase (vent) in pcr determined by denaturing gradient gel electrophoresis. | dna synthesis fidelities of two thermostable dna polymerases, thermus aquaticus (taq) and thermococcus litoralis (tli, also known as vent), and a non-thermostable enzyme, a modified t7 dna polymerase (sequenase), were determined by analyzing polymerase chain reaction (pcr) products using denaturing gradient gel electrophoresis (dgge). the error rates were 4.4, 8.9, and 2.4 x 10(-5) errors/bp for modified t7, taq, and tli polymerase, respectively. reducing the nucleotide triphosphate concentratio ... | 1991 | 1870973 |
| 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 |
| fidelity of dna synthesis by the thermococcus litoralis dna polymerase--an extremely heat stable enzyme with proofreading activity. | we demonstrate that the dna polymerase isolated from thermococcus litoralis (venttm dna polymerase) is the first thermostable dna polymerase reported having a 3'----5' proofreading exonuclease activity. this facilitates a highly accurate dna synthesis in vitro by the polymerase. mutational frequencies observed in the base substitution fidelity assays were in the range of 30 x 10(-6). these values were 5-10 times lower compared to other thermostable dna polymerases lacking the proofreading activi ... | 1991 | 1923765 |
| nucleotide sequence of the gene for elongation factor ef-1 alpha from the extreme thermophilic archaebacterium thermococcus celer. | | 1990 | 2115672 |
| 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 |
| extended secondary structure in 5s rrnas from a sulphur metabolizing archaebacterium, thermococcus celer. | while this sequence shares a significant homology with the 5s rnas of other archaebacteria and is consistent with current models for the secondary structure of 5s rnas, it contains three unusual features. the g + c content (72-74%) is significantly higher than other 5s rnas; the secondary structure is distinguished by unusually stable and extended helical structures and, most important, there is evidence for sequence heterogeneity in the form of complementary base substitutions and precursor pro ... | 1986 | 2418833 |
| aminoglycoside-induced mistranslation in thermophilic archaebacteria. | the effect of selected aminoglycoside antibiotics on the translational accuracy of poly(u) programmed ribosomes derived from the thermophilic archaebacteria thermoplasma acidophilum, sulfolobus solfataricus, thermococcus celer and desulfurococcus mobilis has been determined. under optimum temperature and ionic conditions for polyphenylalanine synthesis, the four species investigated are found to be markedly diverse in their response to the miscoding-inducing action of aminoglycoside antibiotics. ... | 1988 | 2465484 |
| phylogenetic conservation of antigenic determinants in archaebacterial elongation factors (tu proteins). | by using affinity chromatography methods, we have purified elongation factor tu (ef-tu) proteins from a host of archaebacteria covering all known divisions in the archaebacterial tree except halophiles, and from such distantly related eubacteria as thermotoga maritima and escherichia coli. polyclonal antibodies were raised against the tu proteins of sulfolobus solfataricus, thermoproteus tenax, thermococcus celer, pyrococcus wosei, archaeoglobus fulgidus, methanococcus thermolitotrophicus, therm ... | 1989 | 2470483 |
| the structure and evolution of archaebacterial ribosomal rnas. | a cladistic analysis of 553 5s rrna sequences has revealed a ur-5s rrna, the ancestor of all present-day 5s rrna molecules. previously stated characteristic differences between the eubacterial and eukaryotic molecules, namely, the length base-pairing schemes of helices d, can be used as a marker for the various archaebacterial branches. one model comprises thermococcus, thermoplasma, methanobacteria, and halobacteria; a second comprises the sulfolobales; and a third is represented only by the si ... | 1989 | 2470487 |
| multiple termination sites in an unlinked 5s rrna operon in the archaebacterium, thermococcus celer. | the termini of transcripts from an unlinked 5s rrna operon were analyzed in the archaebacterium, thermococcus celer. while the sequences of the 5' termini were completely consistent with the presently accepted consensus promoter sequences, putative multiple termination sites were identified which differed significantly from those identified in other organisms, including archaebacteria. although termination appears to be dependent on a stem/loop structure this structure does not immediately prece ... | 1989 | 2473387 |
| genes encoding 5s rrna and trnas in the extremely thermophilic archaebacterium methanothermus fervidus. | methanothermus fervidus was shown to have two 5s rrna-encoding genes linked in rrna operons to 16s and 23s rrna-encoding genes. sequencing of a cloned 5s rrna gene confirmed that m. fervidus is a member of the methanobacteriales, although its 5s rrna is also similar in both primary sequence and predicted secondary structure to the 5s rrna of the non-methanogenic, but also extremely thermophilic archaebacterium, thermococcus celer. two clusters of trna genes have also been cloned and sequenced fo ... | 1989 | 2473943 |
| chromosome map of the thermophilic archaebacterium thermococcus celer. | a physical map for the chromosome of the thermophilic archaebacterium thermococcus celer vu13 has been constructed. thirty-four restriction endonucleases were tested for their ability to generate large restriction fragments from the chromosome of t. celer. of these, the enzymes nhei, spei, and xbai yielded the fewest fragments when analyzed by pulsed-field electrophoresis. nhei and spei each gave 5 fragments, while xbai gave 12. the size of the t. celer chromosome was determined from the sum of ... | 1989 | 2512284 |
| quinones from archaebacteria, ii. different types of quinones from sulphur-dependent archaebacteria. | from the sulphur-dependent, anaerobically grown archaebacterium sulfolobus ambivalens caldariella quinone, cq-6(12h) and the new sulfolobus quinone sq-6(12h), 6-(3,7,11,15,19,23-hexamethyltetracosyl)-5-methyl-benz[b]thioph en-4, 7-quinone have been isolated as main components. lower homologues sq-5-(10h), sq-4(8h), sq-3(6h), phylloquinone-like species cq-6(10h), sq-6(10h) and the menaquinone mk-6(12h) are present as minor components. the results are compared with those from sulfolobus acidocalda ... | 1986 | 3085688 |
| differential features of ribosomes and of poly(u)-programmed cell-free systems derived from sulphur-dependent archaebacterial species. | the properties of poly(u)-directed cell-free systems developed from the sulphur-dependent, thermophilic archaebacteria desulfurococcus mobilis, thermoproteus tenax, sulfolobus solfataricus, thermococcus celer and thermoplasma acidophilum have been compared. all systems are truly thermophilic in requiring incubation at temperatures close to the physiological optimum for cell growth. under optimized conditions the error frequency in trna selection is less than 0.4% at 80 degrees c, and synthetic e ... | 1986 | 3087750 |
| unique antibiotic sensitivity of archaebacterial polypeptide elongation factors. | the antibiotic sensitivity of the archaebacterial factors catalyzing the binding of aminoacyl-trna to ribosomes (elongation factor tu [ef-tu] for eubacteria and elongation factor 1 [ef1] for eucaryotes) and the translocation of peptidyl-trna (elongation factor g [ef-g] for eubacteria and elongation factor 2 [ef2] for eucaryotes) was investigated by using two ef-tu and ef1 [ef-tu(ef1)]-targeted drugs, kirromycin and pulvomycin, and the ef-g and ef2 [ef-g(ef2)]-targeted drug fusidic acid. the inte ... | 1986 | 3087957 |
| an unlinked 5 s ribosomal rna gene in the archaebacterium, thermococcus celer. | we have determined the nucleotide sequence of an unlinked 5 s rrna gene region from a thermophilic archaebacterium, thermococcus celer. this 5 s rrna gene is flanked by a single trna(asp) sequence and appears to be transcribed as part of a very short operon consisting of only two gene sequences. comparative studies indicate features in the 5' and 3' flanking sequences, which bear similarity with promoter and termination signals in eubacteria, but also reflect unusual features found in at least s ... | 1988 | 3136316 |
| vitamin contents of archaebacteria. | the levels of six water-soluble vitamins of seven archaebacterial species were determined and compared with the levels found in a eubacterium, escherichia coli. biotin, riboflavin, pantothenic acid, nicotinic acid, pyridoxine, and lipoic acid contents of halobacterium volcanii, methanobacterium thermoautotrophicum delta h, "archaeoglobus fulgidus" vc-16, thermococcus celer, pyrodictium occultum, thermoproteus tenax, and sulfolobus solfataricus were measured by using bioassays. the archaebacteria ... | 1988 | 3137215 |
| thermococcus peptonophilus sp. nov., a fast-growing, extremely thermophilic archaebacterium isolated from deep-sea hydrothermal vents. | two extremely thermophilic archaebacteria, strains og-1 and sm-2, were isolated from newly discovered deep-sea hydrothermal vent areas in the western pacific ocean. these strains were cocci, obligately anaerobic archaea about 0.7-2 microm in diameter. optimum growth conditions for og-1 and sm-2 were at 85-90 degrees c (range 60-100 degrees c), ph 6 (range ph 4-8), a nacl concentration of 3% (range 1-5%), and a nutrient concentration (tryptone plus yeast extract) of 0.2% (range 0.005-5%). element ... | 1995 | 7545383 |
| transcription in archaea: similarity to that in eucarya. | we present homologies between archaeal and eucaryal dna-dependent rna polymerase (rnap) subunits and transcription factors. the sequences of the sulfolobus acidocaldarius subunits d, e, and n and alignments with eucaryal homologs are presented here. the similarities between archaeal transcription factors and their eucaryal homologs tfiib and tbp have been established in other laboratories. the archaeal rnap subunits h, k, and n, respectively, show high sequence similarity to abc27, abc23, and ab ... | 1995 | 7597027 |
| the translation product of the presumptive thermococcus celer tata-binding protein sequence is a transcription factor related in structure and function to methanococcus transcription factor b. | a gene for a putative homolog of tata-binding protein (tbp) from thermococcus celer has been expressed in escherichia coli, and the function of the purified recombinant protein was studied in a methanococcus-derived cell-free transcription system. thermococcus tbp can replace archaeal transcription factor b (atfb) in cell-free transcription reactions. this transcriptional activation is tata box-dependent and occurs both on trna(val) and protein-encoding genes as templates indicating that thermoc ... | 1995 | 7629058 |
| effects of elemental sulfur on the metabolism of the deep-sea hyperthermophilic archaeon thermococcus strain es-1: characterization of a sulfur-regulated, non-heme iron alcohol dehydrogenase. | the strictly anaerobic archaeon thermococcus strain es-1 was recently isolated from near a deep-sea hydrothermal vent. it grows at temperatures up to 91 degrees c by the fermentation of peptides and reduces elemental sulfur (s(o)) to h2s. it is shown here that the growth rates and cell yields of strain es-1 are dependent upon the concentration of s(o) in the medium, and no growth was observed in the absence of s(o). the activities of various catabolic enzymes in cells grown under conditions of s ... | 1995 | 7642502 |
| purification, characterization, and metabolic function of tungsten-containing aldehyde ferredoxin oxidoreductase from the hyperthermophilic and proteolytic archaeon thermococcus strain es-1. | thermococcus strain es-1 is a strictly anaerobic, hyperthermophilic archaeon that grows at temperatures up to 91 degrees c by the fermentation of peptides. it is obligately dependent upon elemental sulfur (s(o)) for growth, which it reduces to h2s. cell extracts contain high aldehyde oxidation activity with viologen dyes as electron acceptors. the enzyme responsible, which we term aldehyde ferredoxin oxidoreductase (aor), has been purified to electrophoretic homogeneity. aor is a homodimeric pro ... | 1995 | 7642503 |
| molecular characterization of the genes encoding the tungsten-containing aldehyde ferredoxin oxidoreductase from pyrococcus furiosus and formaldehyde ferredoxin oxidoreductase from thermococcus litoralis. | the hyperthermophilic archaea pyrococcus furiosus and thermococcus litoralis contain the tungstoenzymes aldehyde ferredoxin oxidoreductase, a homodimer, and formaldehyde ferredoxin oxidoreductase, a homotetramer. herein we report the cloning and sequencing of the p. furiosus gene aor (605 residues; m(r), 66,630) and the t. litoralis gene for (621 residues; m(r), 68,941). | 1995 | 7642512 |
| determination of the [fe4s4]cys4 cluster geometry of desulfovibrio africanus ferredoxin i by 1h nmr spectroscopy. | 1d and 2d 1h nmr studies of the fe4s4 cluster containing ferredoxin i from desulfovibrio africanus have been carried out with the aim of determining the geometry of the cluster linkages with the 4 cys side chains that bind the cluster. this required the cys beta ch resonances of the oxidised protein to be sequence-specifically and stereo-specifically assigned, and this was accomplished by a combination of tocsy and noe measurements, allied to model building based on x-ray structures of related f ... | 1995 | 7729544 |
| insights into thermal stability from a comparison of the glutamate dehydrogenases from pyrococcus furiosus and thermococcus litoralis. | in the light of the solution of the three-dimensional structure of the nad(+)-linked glutamate dehydrogenase from the mesophile clostridium symbiosum, we have undertaken a detailed examination of the alignment of the sequences for the thermophilic glutamate dehydrogenases from thermococcus litoralis and pyrococcus furiosus against the sequence and the molecular structure of the glutamate dehydrogenase from c. symbiosum, to provide insights into the molecular basis of their thermostability. this ... | 1995 | 7758464 |
| nucleotide sequence of the genes encoding proline trna(ugg) and threonine trna(ggu) and consensus promoter model of thermococcus celer. | the nucleotide sequences of the genes encoding trna(pro)(ugg) and trna(thr)(ggu) from the extremely thermophilic archaeon (archaebacterium) thermococcus celer have been determined. a consensus promoter model was deduced from the comparison of the upstream regions of several stable rna genes with s1-mapped promoter regions of genes coding for ribosomal proteins and dna-dependent rna polymerase components. | 1993 | 7916630 |
| occurrence of tertiary and quaternary branched polyamines in thermophilic archaebacteria. | polyamines of thermophilic archaebacteria were analysed by high-performance liquid chromatography and gas chromatography. thermoplasma acidophilum and thermoplasma volcanium ubiquitously contained spermidine and spermine. four species of sulfolobus, s. acidocaldarius, s. solfataricus, s. metallicus and s. shibatae, two species of acidianus, a. brierleyi and a. infernus, and metallosphaera sedula, contained norspermidine and norspermine in addition to spermidine and spermine, but quantitative dis ... | 1994 | 7968661 |
| growth requirements of hyperthermophilic sulfur-dependent heterotrophic archaea isolated from a shallow submarine geothermal system with reference to their essential amino acids. | three hyperthermophilic sulfur-dependent heterotrophs were isolated from a shallow submarine hydrothermal system at an inlet of kodakara-jima island, kagoshima, japan. the isolates grew at 60 to 97 degrees c, with the optimum temperatures at 85 to 90 degrees c. sensitivity to rifampin and the existence of ether lipids indicated that the isolates are hyperthermophilic archaea. partial sequencing of the genes coding for 16s rrna showed that the three isolates are closely related to the genus therm ... | 1994 | 8085828 |
| characterization of aromatic aminotransferases from the hyperthermophilic archaeon thermococcus litoralis. | the hyperthermophilic archaeon (formerly archaebacterium) thermococcus litoralis grows at temperatures up to 98 degrees c using peptides and proteins as the sole sources of carbon and nitrogen. cell-free extracts of the organism contained two distinct types of aromatic aminotransferases (ec 2.6.1.57) which were separated and purified to electrophoretic homogeneity. both enzymes are homodimers with subunit masses of approximately 47 kda and 45 kda. using 2-oxoglutarate as the amino acceptor, each ... | 1994 | 8125113 |
| purification and characterization of nadp-specific alcohol dehydrogenase and glutamate dehydrogenase from the hyperthermophilic archaeon thermococcus litoralis. | thermococcus litoralis is a strictly anaerobic archaeon that grows at temperatures up to 98 degrees c by fermenting peptides. little is known about the primary metabolic pathways of this organism and, in particular, the role of enzymes that are dependent on thermolabile nicotinamide nucleotides. in this paper we show that the cytoplasmic fraction of cell extracts contained nadp-specific glutamate dehydrogenase (gdh) and nadp-specific alcohol dehydrogenase (adh) activities, neither of which utili ... | 1994 | 8135516 |
| sequence, assembly and evolution of a primordial ferredoxin from thermotoga maritima. | a gene coding for the ferredoxin of the primordial, strictly anaerobic and hyperthermophilic bacterium thermotoga maritima was cloned, sequenced and expressed in escherichia coli. the ferredoxin gene encodes a polypeptide of 60 amino acids that incorporates a single 4fe-4s cluster. t. maritima ferredoxin expressed in e. coli is a heat-stable, monomeric protein, the spectroscopic properties of which show that its 4fe-4s cluster is correctly assembled within the mesophilic host, and that it remain ... | 1994 | 8168477 |
| the sequence, and its evolutionary implications, of a thermococcus celer protein associated with transcription. | through random search, a gene from thermococcus celer has been identified and sequenced that appears to encode a transcription-associated protein (110 amino acid residues). the sequence has clear homology to approximately the last half of an open reading frame reported previously for sulfolobus acidocaldarius [langer, d. & zillig, w. (1993) nucleic acids res. 21, 2251]. the protein translations of these two archaeal genes in turn are homologs of a small subunit found in eukaryotic rna polymerase ... | 1994 | 8171001 |
| transcription factor iid in the archaea: sequences in the thermococcus celer genome would encode a product closely related to the tata-binding protein of eukaryotes. | the first step in transcription initiation in eukaryotes is mediated by the tata-binding protein, a subunit of the transcription factor iid complex. we have cloned and sequenced the gene for a presumptive homolog of this eukaryotic protein from thermococcus celer, a member of the archaea (formerly archaebacteria). the protein encoded by the archaeal gene is a tandem repeat of a conserved domain, corresponding to the repeated domain in its eukaryotic counterparts. molecular phylogenetic analyses ... | 1994 | 8183889 |
| factors affecting reproducibility of random amplified polymorphic dna fingerprinting. | the reproducibility of random amplified polymorphic dna (rapd) was tested using two different thermal cyclers and three brands of taq dna polymerase. three different oligonucleotides were used to obtain patterns of amplified fragments from three dna samples (escherichia coli, bacillus subtilis, and thermococcus littoralis). experiments were repeated three to six times. apart from the expected between-oligonucleotide and between-dna variations, between-thermal cycler and between-dna polymerase va ... | 1993 | 8248630 |
| enzymes and proteins from organisms that grow near and above 100 degrees c. | microorganisms that can grow at and above 100 degrees c were discovered a decade ago, and about 20 different genera are now known. these so-called hyperthermophiles are the most ancient of all extant life; all but two genera are classified as archaea. all have been isolated from geothermal heated environments including deep-sea hydrothermal vents. this group includes some methanogenic and sulfate-reducing species, but the majority are strictly anaerobic heterotrophs that utilize complex peptide ... | 1993 | 8257111 |
| predominant mutations induced by the thermococcus litoralis, vent dna polymerase during dna amplification in vitro. | we have analyzed the predominant mutations created during dna amplification by pcr utilizing a dna polymerase isolated from the thermococcus litoralis (vent dna polymerase). exon 3 of the human hypoxanthine guanine phosphoribosyl transferase (hprt) gene was amplified using conditions optimized for efficiency of dna amplification. the resulting pcr product was subjected to denaturing gradient gel electrophoresis (dgge) to separate polymerase-induced mutant sequences from correctly amplified seque ... | 1993 | 8324501 |
| characterization, cloning, and in vitro expression of the extremely thermostable glutamate dehydrogenase from the hyperthermophilic archaeon, es4. | glutamate dehydrogenase (gdh) from the hyperthermophilic archaeon es4 (optimal growth temperature 98 degrees c and maximum growth temperature 110 degrees c) was purified to homogeneity. the purified native enzyme had an m(r) of 270,000 +/- 5,000 and was shown by gel filtration and sds-polyacrylamide gel electrophoresis to be a hexamer with identical subunits of m(r) = 46,000 +/- 3,000. the hexameric subunit composition was also evident from electron micrographs, which show a triangular antiprism ... | 1993 | 8349661 |
| characterization of a novel tungsten-containing formaldehyde ferredoxin oxidoreductase from the hyperthermophilic archaeon, thermococcus litoralis. a role for tungsten in peptide catabolism. | thermococcus litoralis is a strictly anaerobic archaeon (archaebacterium) that grows at temperatures up to 98 degrees c by fermenting peptides. its growth is stimulated by tungsten, and a tungsten-containing iron-sulfur protein that has formaldehyde ferredoxin oxidoreductase (for) activity has been purified. for is a homotetramer with a subunit m(r) of 70,000. it contains approximately four irons, four acid-labile sulfides, and one tungsten atom per subunit. the tungsten appears to be present as ... | 1993 | 8390467 |
| characterization of a dna polymerase from the hyperthermophile archaea thermococcus litoralis. vent dna polymerase, steady state kinetics, thermal stability, processivity, strand displacement, and exonuclease activities. | we have isolated, cloned, and characterized a dna polymerase from the hyperthermophile archaea thermococcus litoralis, the tli dna polymerase (also referred to as vent dna polymerase). the enzyme is extremely thermostable, having a half-life of 8 h at 95 degrees c and about 2 h at 100 degrees c. pseudo-first-order kinetics at 70 degrees c reveal an extremely low km for a primed m13mp18 substrate (0.1 nm), coupled with a relatively high km for dntps (50 microm). accompanying extension rates are o ... | 1993 | 8420970 |
| identification of molybdopterin as the organic component of the tungsten cofactor in four enzymes from hyperthermophilic archaea. | the hyperthermophilic archaea represent some of the most ancient organisms on earth. a study of enzymatic cofactors in these organisms could provide basic information on the origins of related cofactors in man and other more recently evolved organisms. to this end, the nature of the tungsten cofactor in aldehyde ferredoxin oxidoreductases from pyrococcus furiosus and es-4 and in formaldehyde ferredoxin oxidoreductases from p. furiosus and thermococcus litoralis has been investigated. all four pr ... | 1993 | 8444863 |
| structures of the modified folates in the extremely thermophilic archaebacterium thermococcus litoralis. | the chemical structures of the two modified folates present in thermococcus litoralis were established. these compounds, each containing a core structure of 1-[4-[[1-(2-amino-7-methyl- 4-oxo-6-pteridinyl)-ethyl]amino]phenyl]-1-deoxy-[1-alpha-d- ribofuranosyl]-ribitol, were characterized. the five position of the ribose in this core structure was beta-linked to the c-1 of a poly-beta (1-->4)n-acetylglucosamine having a chain length of four or five n-acetylglucosamine residues. thus, these compoun ... | 1993 | 8501071 |
| a hyperthermophilic sulfur-reducing archaebacterium, thermococcus sp. dt1331, isolated from a deep-sea hydrothermal vent. | a hyperthermophilic archaebacterium was isolated from a deep-sea black smoker chimney (depth, 760 m) at the minami-ensei knoll (28 degrees 23'n, 127 degrees 38'e). the strain, designated dt1331, was a coccoid shaped bacterium about 0.5 to 1.0 microns in diameter. the cells were surrounded by a cell envelope. the temperature for growth was between 55 degrees c and 93 degrees c with an optimum 80 degrees c. the growth occurred from ph 4.5 to 8.5 and the optimum ph was 6.0. dt1331 required 1% to 5% ... | 1995 | 8520110 |
| properties and stabilization of an extracellular alpha-glucosidase from the extremely thermophilic archaebacteria thermococcus strain an1: enzyme activity at 130 degrees c. | an extracellular alpha-glucosidase from the thermophilic archaebacterium thermococcus strain an1 was purified 875-fold in five steps (hiload q-sepharose, phenyl sepharose, hpht-hydroxyapatite, gel filtration and mono q chromatography) with a yield of 4%. it is a monomer with a molecular mass of about 60 kda and a pi around 5. at 98 degrees c, the purified enzyme in buffer has a half-life around 35 min, which is increased to around 215 min in presence of 1% (w/v) dithiothreitol and 1% (w/v) bsa. ... | 1996 | 8547344 |
| characterization of 2-ketoisovalerate ferredoxin oxidoreductase, a new and reversible coenzyme a-dependent enzyme involved in peptide fermentation by hyperthermophilic archaea. | cell extracts of the proteolytic and hyperthermophilic archaea thermococcus litoralis, thermococcus sp. strain es-1, pyrococcus furiosus, and pyrococcus sp. strain es-4 contain an enzyme which catalyzes the coenzyme a-dependent oxidation of branched-chain 2-ketoacids coupled to the reduction of viologen dyes or ferredoxin. this enzyme, termed vor (for keto-valine-ferredoxin oxidoreductase), has been purified from all four organisms. all four vors comprise four different subunits and show amino-t ... | 1996 | 8550513 |
| thermococcus alcaliphilus sp. nov., a new hyperthermophilic archaeum growing on polysulfide at alkaline ph. | a novel coccoid-shaped, hyperthermophilic, heterotrophic member of the archaea was isolated from a shallow marine hydrothermal system at vulcano island, italy. the isolate grew between 56 and 90 degrees c with an optimum around 85 degrees c. the ph range for growth was 6.5 to 10.5, with an optimum around 9.0. polysulfide and elemental sulfur were reduced to h2s. sulfur stimulated the growth rate. the isolate fermented yeast extract, peptone, meat extract, tryptone, and casein. isovalerate, isobu ... | 1995 | 8588740 |
| 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 thermostable dna polymerases from hyperthermophilic marine archaea with emphasis on thermococcus sp. 9 degrees n-7 and mutations affecting 3'-5' exonuclease activity. | five extremely thermophilic archaea from hydrothermal vents were isolated, and their dna polymerases were cloned and expressed in escherichia coli. protein splicing elements (inteins) are present in many archaeal dna polymerases, but only the dna polymerase from strain gb-c contained an intein. of the five cloned dna polymerases, the thermococcus sp. 9 degrees n-7 dna polymerase was chosen for biochemical characterization. thermococcus sp. 9 degrees n-7 dna polymerase exhibited temperature-sensi ... | 1996 | 8643567 |
| a gene, han1a, encoding an archaeal histone-like protein from the thermococcus species an1: homology with eukaryal histone consensus sequences and the implications for delineation of the histone fold. | the han1a gene, encoding a subunit of the histone-like protein han1 from the thermococcus species an1, has been cloned and sequenced. sequence analysis of the translation product of the gene demonstrates homology with other archaeal histone-like proteins of the 'hmf family' and eukaryal consensus sequences, particularly h4. the region of highest homology between the an1 histone subunit, termed the han1a1 subunit, and the h4 consensus is suggested, by the 3-dimensional structure of the histone oc ... | 1996 | 8652658 |
| culturability and survival of an extreme thermophile isolated from deep-sea hydrothermal vents | the culturability of a strictly anaerobic, extremely thermophilic archaeon, thermococcus peptonophilus (optimal growth temperature: 85° c), was studied during survival stages at various temperatures (98, 85, 70, and 4° c). total cell number (determined by dapi staining), active cells (rhodamine-stained cells), and culturable cells (using most-probable-number) were counted over time. the number of culturable cells decreased under each condition tested. the total number of cells significan ... | 1996 | 8661946 |
| tungsten in biological systems. | tungsten (atomic number 74) and the chemically analogous and very similar metal molybdenum (atomic number 42) are minor yet equally abundant elements on this planet. the essential role of molybdenum in biology has been known for decades and molybdoenzymes are ubiquitous. yet, it is only recently that a biological role for tungsten has been established in prokaryotes, although not as yet in eukaryotes. the best characterized organisms with regard to their metabolism of tungsten are certain specie ... | 1996 | 8672295 |
| properties of glutamate dehydrogenase and its involvement in alanine production in a hyperthermophilic archaeon, thermococcus profundus. | thermococcus profundus, a hyperthermophilic archaeon, did not exhibit detectable glutamine synthetase activity, although the organism possessed an extraordinarily high level of glutamate dehydrogenase (gdh), the content of which reached over 10% of total soluble proteins. this gdh was purified to homogeneity. the enzyme had a molecular weight of 263,000 and was composed of six homogeneous subunits of molecular weight 43,000. the enzyme was extremely thermostable with a half life of 1 h at 90 deg ... | 1995 | 8690722 |
| a cell-free transcription system for the hyperthermophilic archaeon pyrococcus furiosus. | we describe here the establishment of a cell-free transcription system for the hyperthermophilic archaeon pyrococcus furiosus using the cloned glutamate dehydrogenase (gdh) gene as template. the in vitro system that operated up to a temperature of 85 degrees c initiated transcription 23 bp downstream of a tata box located 45 bp upstream of the translational start codon of gdh mrna, at the same site as in pyrococcus cells. mutational analyses revealed that this tata box is essential for in vitro ... | 1996 | 8710509 |
| 1h nmr investigation of the secondary structure, tertiary contacts and cluster environment of the four-iron ferredoxin from the hyperthermophilic archaeon thermococcus litoralis. | the solution molecular structure of the four-iron ferredoxin (fd) from the hyperthermophilic archaeon thermococcus litoralis (tl) has been investigated by 1h nmr spectroscopy. tocsy and noesy experiments in h2o, tailored to detect both weakly and strongly relaxed resonances, together with steady-state noes in both h2o and d2o, allowed the identification of 58 of the 59 residues, with one residue near the paramagnetic center undetected. it is shown that the contact shifted and strongly relaxed si ... | 1996 | 8720830 |
| high-affinity maltose/trehalose transport system in the hyperthermophilic archaeon thermococcus litoralis. | the hyperthermophilic marine archaeon thermococcus litoralis exhibits high-affinity transport activity for maltose and trehalose at 85 degrees c. the k(m) for maltose transport was 22 nm, and that for trehalose was 17 nm. in cells that had been grown on peptone plus yeast extract, the vmax for maltose uptake ranged from 3.2 to 7.5 nmol/min/mg of protein in different cell cultures. cells grown in peptone without yeast extract did not show significant maltose or trehalose uptake. we found that the ... | 1996 | 8759837 |
| l-alanine production from glucose fermentation by hyperthermophilic members of the domains bacteria and archaea: a remnant of an ancestral metabolism? | new members of the order thermotogales were isolated from nonvolcanically heated geothermal environments, including oil fields and waters of the great artesian basin of australia, thereby extending their known habitats, previously recognized primarily as volcanic. the hyperthermophilic and thermophilic members of thermotogales of volcanic origin, together with the recently described nonvolcanic species of this order and three new isolates described in this paper, were all found to produce l-alan ... | 1996 | 8779604 |
| molecular model of the solution structure for the paramagnetic four-iron ferredoxin from the hyperthermophilic archaeon thermococcus litoralis. | a molecular model for the three-dimensional solution structure of the paramagnetic, four-iron ferredoxin (fd) from the hyperthermophilic archaeon thermococcus litoralis (tl) has been constructed on the basis of the reported 1h nmr spectral parameters [donaire, a. (1996) j. biomol. nmr 7, 35-47]. the conventional use of long mixing time noesy cross-peak intensity, backbone angles, and hydrogenbonding constraints for building the structure was augmented by short mixing time noesy, steady-state noe ... | 1996 | 8784186 |
| characterization of a fourth type of 2-keto acid-oxidizing enzyme from a hyperthermophilic archaeon: 2-ketoglutarate ferredoxin oxidoreductase from thermococcus litoralis. | thermococcus litoralis is a strictly anaerobic archaeon (archaebacterium) that grows at temperatures up to 98 degrees c by fermenting peptides. it is known to contain three distinct ferredoxin-dependent, 2-keto acid oxidoreductases, which use pyruvate, aromatic 2-keto acids such as indolepyruvate, or branched-chain 2-keto acids such as 2-ketoisovalerate, as their primary substrates. we show here that t. litoralis also contains a fourth member of this family of enzymes, 2-ketoglutarate ferredoxin ... | 1996 | 8830683 |
| 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 |
| purification and characterization of a histone-like protein from the archaeal isolate an1, a member of the thermococcales. | we have purified and characterized the histone-like protein, termed han1, and an han1-associated dna-binding protein (hdbp) from nucleoids of the hyperthermophilic thermococcus-like an1. han1 is shown to be composed of two subunits, to be thermally stable and to compact dna in a reversible manner. the n-terminal sequence of han1 shares a high degree of homology with hmf, the histone-like protein from methanothermus fervidus. consistent with this, the toroidal wrapping of dna by han1 resembles th ... | 1996 | 8861206 |
| thermococcus fumicolans sp. nov., a new hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent in the north fiji basin. | an extremely thermophilic archaeon, strain st557t (t = type strain), was isolated from a deep-sea hydrothermal vent in the north fiji basin. this strain is a strictly anaerbic coccus whose cells are about 0.8 to 2 microns in diameter. the optimum temperature, ph and sea salt concentration for growth are 85 degrees c, 8.5, and 20 to 40 g/liter, respectively. strain st557t grows preferentially in the presence of elemental sulfur on proteinaceous substrates and on a mixture of 20 amino acids. it gr ... | 1996 | 8863444 |
| genomic structure of the maize tata-box binding protein 1 (tbp-1): conserved exon/intron structure in eukaryotic tbp genes. | the gene system of the tata-box binding protein (tbp) is well suited for the study of the evolutionary conservation of essential components of eukaryotic transcription initiation. in this context we have isolated and sequenced the maize tbp gene for a comparison with tbp genes from other organisms. in particular, a molecular phylogenetic analysis of the exon/intron structure of these genes including the archaeal tbp homolog (thermococcus celer) was performed, revealing that the intron insertion ... | 1996 | 8863736 |
| uv and ethyl methanesulfonate effects in hyperthermophilic archaea and isolation of auxotrophic mutants of pyrococcus strains. | the lethal and mutagenic effects of ethyl methanesulfonate (ems) and uv on nine archaeal strains belonging to each of the two described genera of thermococcales, pyrococcus and thermococcus, were investigated. to test the efficiency of the ems and uv mutagenesis under a variety of experimental conditions, we chose pyrococcus abyssi strain ge5 as a model strain. we observed a strong induced mutagenicity in both cases, since the spontaneous mutation frequency (expressed as the frequency of resista ... | 1996 | 8900104 |
| vacuolar-type atpase in a hyperthermophilic archaeum, thermococcus sp. ki. | membrane atpase was purified from a hyperthermophilic heterotrophic archaeum, thermococcus sp. ki, which grew anaerobically at 90 degrees c in the presence of sulfur. the purified enzyme had an optimal temperature of 90 degrees c and its molecular mass was estimated to be 600 kda. it consisted of 4 subunits with molecular masses of 70, 60, 29 and 15 kda. while the atpase activity was resistant to most atpase inhibitors, the activity was reduced by nitrate, an inhibitor of the vacuolar (v)-type a ... | 1996 | 8954937 |
| 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 |
| dna topology in hyperthermophilic archaea: reference states and their variation with growth phase, growth temperature, and temperature stresses. | in order to address the dynamics of dna topology in hyperthermophilic archaea, we analysed the topological state of several plasmids recently discovered in thermococcales and sulfolobales. all of these plasmids were from relaxed to highly positively supercoiled in vitro, i.e. they exhibited a significant linking excess compared to the negatively supercoiled plasmids from mesophilic organisms (both archaea and bacteria). in the two archaeal orders, plasmid linking number (lk) decreased as growth ... | 1997 | 9106217 |
| structures and functions of four anabolic 2-oxoacid oxidoreductases in methanobacterium thermoautotrophicum. | methanobacterium thermoautotrophicum (strain marburg), which grows autotrophically on h2 and co2, was found to contain 2-oxoisovalerate oxidoreductase (vor) and indolepyruvate oxidoreductase (ior) besides pyruvate oxidoreductase (por) and 2-oxoglutarate oxidoreductase (kor). so far, vor and ior have only been detected in peptide-utilizing hyperthermophilic archaea. the four 2-oxoacid oxidoreductases were purified and characterized with respect to their subunit composition, n-terminal amino acid ... | 1997 | 9108258 |
| identification of a gene in the euryarchaeal thermococcus species an1 encoding a protein homologous to the alpha subunit of the eukaryal signal recognition particle (srp) receptor. | we describe here the sequence and transcriptional analysis of a gene from the euryarchaeal thermococcus species an1 (dsm 2770) encoding a protein homologous to the alpha subunit of the eukaryal srp receptor (sr alpha). the an1 protein is found to share the highest degree of homology with the only other described archaeal sr alpha homolog characterized from the hyperthermophilic crenarchaeal sulfolobus solfataricus. sequence analysis of the translation of the an1 gene reveals the presence of the ... | 1997 | 9116022 |
| biochemical and phylogenetic characterization of two novel deep-sea thermococcus isolates with potentially biotechnological applications. | the partial 16s rdna gene sequences of two thermophilic archaeal strains, ty and tys, previously isolated from the guaymas basin hydrothermal vent site were determined. lipid analyses and a comparative analysis performed with 16s rdna sequences of similar thermophilic species showed that the strains isolated from deep-sea vents were not identical to the other species belonging to the genus thermococcus. on the basis of the results of the phylogenetic analyses, lipid analyses, and previously repo ... | 1997 | 9148682 |
| genetic information 'created' by archaebacterial dna polymerase. | dna polymerase catalyses replication of cellular dna. the reaction requires a primer-template complex, and a new dna chain grows from the 3' end of the primer along the template; no genetic information is created in this reaction. we demonstrate that dna polymerase from thermococcus litoralis, a hyperthermophilic marine archaea, can synthesize up to 50000 bp of linear double-stranded dna in the complete absence of a primer-template complex, indicating that genetic information is 'created.' the p ... | 1997 | 9182732 |
| purification and sequence analysis of a novel nadp(h)-dependent type iii alcohol dehydrogenase from thermococcus strain an1. | an nadp(h)-dependent alcohol dehydrogenase was isolated from the hyperthermophilic archaeon thermococcus strain an1. this enzyme is a homotetramer with a subunit molecular weight of 46,700. the enzyme oxidizes a series of primary linear alcohols but not methanol. the ph and temperature optima with ethanol as the substrate are 6.8 to 7.0 and 85 degrees c, respectively. the enzyme readily reduced acetaldehyde with nadph as the cofactor. the gene encoding this enzyme has been cloned and sequenced. ... | 1997 | 9209068 |
| pressure and temperature effects on growth and viability of the hyperthermophilic archaeon thermococcus peptonophilus. | we studied the effects of high temperatures and elevated hydrostatic pressures on the physiological behavior and viability of the extremely thermophilic deep-sea archaeon thermococcus peptonophilus. maximal growth rates were observed at 30 and 45 mpa although no significant increases in cell yields were detected. growth at 60 mpa was slower. the optimal growth temperature shifted from 85 degrees c at 30 mpa to 90-95 degrees c at 45 mpa. cell viability during the stationary phase was also enhance ... | 1997 | 9211707 |
| thermococcus hydrothermalis sp. nov., a new hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent. | an extremely thermophilic archaeon, strain al662t, was isolated from a deep-sea hydrothermal vent located on the east pacific rise at a latitude of 21 degrees n. this strain is a strictly anaerobic coccus, and its cells range from 0.8 to 2 microns in diameter. the optimum temperature, ph, and sea salt concentration for growth are 85 degrees c, 6, and 20 to 40 g/liter, respectively. strain al662t grows preferentially on proteolysis products, on a mixture of 20 amino acids, and on maltose in the p ... | 1997 | 9226891 |
| development of a technique for multiple site-directed mutagenesis of the ftf gene of streptococcus salivarius containing palindromic sequences. | attempts at site-directed mutagenesis of the fructosyltransferase (ftf) gene of streptococcus salivarius atcc 25975 using standard protocols were unsuccessful and resulted in a series of deletions. these deletions appeared to commence at points within the ftf gene where there were palindromic sequences which were capable of forming closed loop structures that acted as terminators under the conditions of mutagenesis. to overcome this problem, two modified mutagenic techniques were developed. they ... | 1997 | 9271874 |
| 4-alpha-glucanotransferase from the hyperthermophilic archaeon thermococcus litoralis--enzyme purification and characterization, and gene cloning, sequencing and expression in escherichia coli. | 4-alpha-glucanotransferase was purified from cells of thermococcus litoralis, a hyperthermophilic archaeon. the molecular mass of the enzyme was estimated to be approximately 87 kda by gel filtration. the optimal temperature for its activity was 90 degrees c. the enzyme catalyzed the transglycosylation of maltooligosaccharides, yielding maltooligosaccharides of various lengths and glucose. when maltoheptaose was used as the substrate, glucoamylase-resistant and glucoamylase-sensitive saccharides ... | 1997 | 9310375 |
| structural and functional characterization of homo-oligomeric complexes of alpha and beta chaperonin subunits from the hyperthermophilic archaeum thermococcus strain ks-1. | to elucidate the function of group ii chaperonin, the gene for the chaperonin from the hyperthermophilic archaeum thermococcus strain ks-1 was cloned and sequenced. two distinct genes coding for chaperonin subunits, designated alpha and beta, were obtained, and their deduced amino acid sequences are highly homologous to those of group ii chaperonins from other sources. the alpha and beta subunits were individually expressed in escherichia coli. both of the recombinant subunits assemble to consti ... | 1997 | 9356252 |
| alpha- and beta-subunits of a v-type membrane atpase in a hyperthermophilic sulfur-dependent archaeum, thermococcus sp. ki. | the genes encoding alpha- and beta-subunits of a v-type atpase in a sulfur-dependent hyperthermophilic archaeum, thermococcus sp. ki, were cloned and sequenced. the deduced amino acid sequences were approximately 60, 50 and 25% identical to those of other archaeal, eukaryotic v-type and e. coli f-type atpase, respectively. phylogenetic analysis revealed that thermococcus atpase was closely related to that of thermus, and those of methanosarcina and halobacterium. | 1997 | 9370240 |
| the phylogenetic position of the thermococcus isolate an1 based on 16s rrna gene sequence analysis: a proposal that an1 represents a new species, thermococcus zilligii sp. nov. | the 16s rrna gene from the thermococcus new zealand isolate an1 was cloned and sequenced. analysis of the gene revealed the presence of signature sequences, indicating that strain an1 represents a new species of the genus thermococcus. since the isolate an1 differed from other thermococci in both its lower optimal nacl concentration and generally lower optimal temperature for growth, in its unusual lipid membrane composition, and in its sensitivity to antibiotics, we propose that strain an1 repr ... | 1997 | 9382704 |
| purification and properties of an extremely thermostable nadp+-specific glutamate dehydrogenase from archaeoglobus fulgidus. | nadp+-specific glutamate dehydrogenase (ec 1.4.1.4) was purified to homogeneity from the extremely thermophilic, strictly anaerobic, sulfate-reducing archaeon archaeoglobus fulgidus strain 7324. the native enzyme (263 kda) is composed of subunits of mol. mass 46 kda, suggesting a hexameric structure. the temperature optimum for enzyme activity was > 95 degrees c. the enzyme was highly thermostable, having a half-life of 140 min at 100 degrees c. potassium phosphate, kcl, and nacl enhanced the th ... | 1997 | 9385147 |
| homology modelling of two subtilisin-like proteases from the hyperthermophilic archaea pyrococcus furiosus and thermococcus stetteri. | the hyperthermophilic archaeon pyrococcus furiosus produces an extracellular, glycosylated hyperthermostable subtilisin-like serine protease, termed pyrolysin (voorhorst,w.g.b., eggen,r.i.l., geerling,a.c.m., platteeuw,c., siezen,r.j. and de vos,w.m. (1996) j. biol. chem., 271, 20426-20431). based on the pyrolysin coding sequence, a pyrolysin-like gene fragment was cloned and characterized from the extreme thermophilic archaeon thermococcus stetteri. like pyrolysin, the deduced sequence of this ... | 1997 | 9415440 |
| cloning and characterisation of a thermostable alpha-dna polymerase from the hyperthermophilic archaeon thermococcus sp. ty. | the gene for an extremely thermostable dna polymerase has been cloned from chromosomal dna of the recently characterised hyperthermophilic archaeon thermococcus sp. ty by using degenerate primers derived from consensus sequences of known archaeal enzymes. the corresponding enzyme was overexpressed in escherichia coli. sequence comparison of the gene with related dna polymerase genes revealed that it is interrupted by three regions showing high similarities to self-splicing protein elements, so-c ... | 1997 | 9434178 |
| archaeal binding protein-dependent abc transporter: molecular and biochemical analysis of the trehalose/maltose transport system of the hyperthermophilic archaeon thermococcus litoralis. | we report the cloning and sequencing of a gene cluster encoding a maltose/trehalose transport system of the hyperthermophilic archaeon thermococcus litoralis that is homologous to the malefg cluster encoding the escherichia coli maltose transport system. the deduced amino acid sequence of the male product, the trehalose/maltose-binding protein (tmbp), shows at its n terminus a signal sequence typical for bacterial secreted proteins containing a glyceride lipid modification at the n-terminal cyst ... | 1998 | 9457875 |
| characterization of homo-oligomeric complexes of alpha and beta chaperonin subunits from the acidothermophilic archaeon, sulfolobus sp. strain 7. | the chaperonin from the acidothermophilic archaeon, sulfolobus sp. strain 7, is composed of two kinds of subunits designated as scp alpha and scp beta. in this study, we characterized the recombinant scp alpha and scp beta, which were separately expressed in escherichia coli. both of them were able to assemble to homo-oligomeric double-ring complexes, similar to subunits of group ii chaperonins from thermoplasma acidophilum and thermococcus strain ks-1. both complexes have no or at most trace at ... | 1998 | 9464270 |
| isolation of thermostable phosphatase from the hyperthermophilic archaeon thermococcus pacificus by immobilized metal affinity chromatography. | phosphatase was isolated from cells of the hyperthermophilic marine archaeon thermococcus pacificus by a procedure including chromatography on butyl-fractogel tsk-650 and ni(2+)-iminodiacetic-agarose. enzyme activity is maximal at 90 degrees c, and the enzyme half-life time at this temperature is 1 h. the ph optimum of phosphatase activity is 6.0. electrophoresis under denaturating conditions yielded a subunit molecular weight of 45 kda. on gel-filtration on sephacryl s-300 hr three peak corresp ... | 1998 | 9530518 |
| thermococcus gorgonarius sp. nov. and thermococcus pacificus sp. nov.: heterotrophic extremely thermophilic archaea from new zealand submarine hot vents. | two extremely thermophilic archaea, designated w-12 and p-4, were isolated from a geothermal vent in the tidal zone of whale island, new zealand, and from geothermally heated bottom deposits of the bay of plenty, new zealand, respectively. cells of isolate w-12 are irregular cocci, 0.3-1.2 microns in diameter, motile with polar flagella. the cell envelope consists of one layer of subunits with a major protein of m(r) 75,000. cells produce protrusions of different kinds: prostheca-like, chains of ... | 1998 | 9542072 |
| lipids of thermococcus hydrothermalis, an archaea isolated from a deep-sea hydrothermal vent. | the membrane lipids of a deep-sea hydrothermal vent archaea, thermococcus hydrothermalis, were isolated, purified, and structurally characterized. on the basis of acid methanolysis and spectroscopic studies, the polar lipids, amounting to 4.5% (w/w) of the dry cells, comprised diphytanyl glycerol diethers and dibiphytanyldiglycerol tetraethers, in a 45:55 ratio. no cyclopentane ring was present in the tetraethers. from the neutral lipids, accounting for 0.4% (w/w) of the dry cells, besides low a ... | 1998 | 9560807 |
| thermostable archaeal o6-alkylguanine-dna alkyltransferases. | archaea represent some of the most ancient organisms on earth, and they have relatively uncharacterized dna repair processes. we now show, using an in vitro assay, that extracts of two crenarchaeota (sulfolobus acidocaldarius and pyrobaculum islandicum) and two euryarchaeota (pyrococcus furiosus and thermococcus litoralis) contain the dna repair protein o6-alkylguanine-dna alkyltransferase (atase). the atase activities found in the archaea were extremely thermostable, with half-lives at 80 degre ... | 1998 | 9618477 |