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Giovanni Sannia - One of the best experts on this subject based on the ideXlab platform.
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Glutamate-1-semialdehyde aminotransferase from Sulfolobus solfataricus
Biochemical Journal, 1996Co-Authors: Gianna Palmieri, Gennaro Marino, M Di Palo, Andrea Scaloni, Stefania Orrù, Giovanni SanniaAbstract: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 aminotransferase is indicative of the presence of pyridoxamine 5'-phosphate (PMP) cofactor, and the catalytic activity of the enzyme is further stimulated by addition of PMP. 3-Amino-2,3-dihydrobenzoic acid is an inhibitor of the aminotransferase activity. The N-terminal amino acid sequence of GSA-AT from S. solfataricus was found to share significant similarity with the eukaryotic and eubacterial enzymes. Evidence is provided that ALA synthesis in S. solfataricus follows the C5 pathway characteristic of plants, algae, cyanobacteria and many other bacteria.
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Tryptophan biosynthesis genes trpEGC in the thermoacidophilic archaebacterium Sulfolobus solfataricus.
Journal of bacteriology, 1993Co-Authors: Maria Luisa Tutino, Giovanni Sannia, Gennaro Marino, G Scarano, Maria Vittoria CubellisAbstract: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 same as those measured when comparing the eubacterial and eukaryotic sequences directly. These percentages did not rise significantly when a comparison with the proteins from Haloferax volcanii was drawn, while a slightly closer relationship with the proteins from Methanococcus thermoautotrophicum was found.
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The active site of Sulfolobus solfataricus aspartate aminotransferase.
Biochimica et biophysica acta, 1991Co-Authors: Leila Birolo, Maria Immacolata Arnone, Maria Vittoria Cubellis, Giuseppina Andreotti, Gianpaolo Nitti, Gennaro Marino, Giovanni SanniaAbstract:Abstract Aspartate aminotransferase from the archaebacterium Sulfolobus solfataricus binds pyridoxal 5′ phosphate, via an aldimine bond, with Lys-241. This residue has been identified by reducing the enzyme in the pyridoxal form with sodium cyanoboro[ 3 H]hydride and sequencing the specifically labeled peptic peptides. The aminoacidic sequence centered around the coenzyme binding site is highly conserved between thermophilic aspartate aminotransferases and differs from that found in mesophilic isoenzymes. An alignment of aspartate aminotransferase from Sulfolobus solfataricus with mesophilic isoenzymes, attempted in spite of the low degree of similarity, was confirmed by the correspondence between pyridoxal 5′ phosphate binding residues. Using this alignment it was possible to insert the archaebacterial aspartate aminotransferase into a subclass I, of pyridoxal 5′ phosphate binding enzymes comprising mesophilic aspartate aminotransferases, tyrosine aminotransferases and histidinol phosphate aminotransferases. These enzymes share 12 invariant amino acids most of which interact with the coenzyme or with the substrates. Some enzymes of subclass I and in particular aspartate aminotransferase from Sulfolobus solfataricus , lack a positively charged residue, corresponding to Arg-292, which in pig cytosolic aspartate aminotransferase interacts with the distal carboxylate of the substrates (and determines the specificity towards dicarboxylic acids). It was confirmed that aspartate aminotransferase from Sulfolobus solfataricus does not possess any arginine residue exposed to chemical modifications responsible for the binding of ω-carboxylate of the substrates. Furthermore, it has been found that aspartate aminotransferase from Sulfolobus solfataricus is fairly active when alanine is used as substrate and that this activity is not affected by the presence of formate. The K M value of the thermophilic aspartate aminotransferase towards alanine is at least one order of magnitude lower than that of the mesophilic analogue enzymes.
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The Functioning of Sulfolobus solfataricus Aspartate Aminotransferase
Enzymes Dependent on Pyridoxal Phosphate and Other Carbonyl Compounds As Cofactors, 1991Co-Authors: Leila Birolo, Maria Vittoria Cubellis, Gennaro Marino, M. Immacolata Arnione, Giovanni SanniaAbstract:ABSTRACT Aspartate aminotransferase from Sulfolobus solfataricus is a hypertermophilic enzyme. It shows the usual ping-pong mechanism and forms the expected internal and external aldimines. Surprisingly, however, erythro-3-hydroxy-aspartate does not give rise to a stable quinonoid intermediate as no absorbance is observed at 490nm. It is also worthwhile mentioning that the pKa of the chromophore is well below the values observed for other aspartate aminotransferases.
Mose Rossi - One of the best experts on this subject based on the ideXlab platform.
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a new pepstatin insensitive thermopsin like protease overproduced in peptide rich cultures of Sulfolobus solfataricus
International Journal of Molecular Sciences, 2014Co-Authors: Marta Gogliettino, Mose Rossi, Gianna Palmieri, Alessia Riccio, Ennio Cocca, Marco BalestrieriAbstract:In this study, we gain insight into the extracellular proteolytic system of Sulfolobus solfataricus grown on proteinaceous substrates, providing further evidence that acidic proteases were specifically produced in response to peptide-rich media. The main proteolytic component was the previously isolated SsMTP (Sulfolobus solfataricus multi-domain thermopsin-like protease), while the less abundant (named SsMTP-1) one was purified, characterized and identified as the sso1175 gene-product. The protein revealed a multi-domain organization shared with the cognate SsMTP with a catalytic domain followed by several tandemly-repeated motifs. Moreover, both enzymes were found spread across the Crenarchaeota phylum and belonging to the thermopsin family, although segregated into diverse phylogenetic clusters. SsMTP-1 showed a 75-kDa molecular mass and was stable in the temperature range 50–90 °C, with optimal activity at 70 °C and pH 2.0. Serine, metallo and aspartic protease inhibitors did not affect the enzyme activity, designating SsMTP-1 as a new member of the pepstatin-insensitive aspartic protease family. The peptide-bond-specificity of SsMTP-1 in the cleavage of the oxidized insulin B chain was uncommon amongst thermopsins, suggesting that it could play a distinct, but cooperative role in the protein degradation machinery. Interestingly, predictions of the transmembrane protein topology of SsMTP and SsMTP-1 strongly suggest a possible contribution in signal-transduction pathways.
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The prefoldin of the crenarchaeon Sulfolobus solfataricus.
Protein and peptide letters, 2008Co-Authors: Anna D'amaro, Mose Rossi, Anna Valenti, Alessandra Napoli, Maria CiaramellaAbstract:Prefoldin is a hetero-hexameric ATP-independent chaperone, shared by eukaryotes and archaea, which binds non-native proteins preventing them from aggregation. We report the identification and characterization in vivo and in vitro of the first prefoldin from a crenarchaeon, the hyperthermophile Sulfolobus solfataricus. A functional complex was obtained either co-expressing the α- and β-prefoldin subunits in Escherichia coli, or incubating at high temperature the separately expressed subunits. In S. solfataricus, prefoldin expression and apparent molecular weight were not affected by either heat or cold shock.
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The α-l-fucosidase from Sulfolobus solfataricus
Extremophiles, 2008Co-Authors: Beatrice Cobucci-ponzano, Mose Rossi, Fiorella Conte, Marco MoracciAbstract:Glycoside hydrolases form hyperthermophilic archaea are interesting model systems for the study of catalysis at high temperatures and, at the moment, their detailed enzymological characterization is the only approach to define their role in vivo. Family 29 of glycoside hydrolases classification groups α- l -fucosidases involved in a variety of biological events in Bacteria and Eukarya . In Archaea the first α- l -fucosidase was identified in Sulfolobus solfataricus as interrupted gene expressed by programmed −1 frameshifting. In this review, we describe the identification of the catalytic residues of the archaeal enzyme, by means of the chemical rescue strategy. The intrinsic stability of the hyperthermophilic enzyme allowed the use of this method, which resulted of general applicability for β and α glycoside hydrolases. In addition, the presence in the active site of the archaeal enzyme of a triad of catalytic residues is a rather uncommon feature among the glycoside hydrolases and suggested that in family 29 slightly different catalytic machineries coexist.
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Crystallization and preliminary X-ray diffraction analysis of the hyperthermophilic Sulfolobus solfataricus phosphotriesterase.
Acta Crystallographica Section F Structural Biology and Crystallization Communications, 2007Co-Authors: Mikael Elias, Mose Rossi, Giuseppe Manco, Jérôme Dupuy, Luigia Merone, Claude Lecomte, Patrick Masson, Eric ChabrièreAbstract:Organophosphates constitute the largest class of insecticides used worldwide and some of them are potent nerve agents. Consequently, organophosphate-degrading enzymes are of paramount interest as they could be used as bioscavengers and biodecontaminants. Phosphotriesterases (PTEs) are capable of hydrolyzing these toxic compounds with high efficiency. A distant and hyperthermophilic representative of the PTE family was cloned from the archeon Sulfolobus solfataricus MT4, overexpressed in Escherichia coli and crystallized; the crystals diffracted to 2.54 A resolution. Owing to its exceptional thermostability, this PTE may be an excellent candidate for obtaining an efficient organophosphate biodecontaminant. Here, the crystallization conditions and data collection for the hyperthermophilic S. solfataricus PTE are reported.
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Highly Productive Autocondensation and Transglycosylation Reactions with Sulfolobus solfataricus Glycosynthase
Chembiochem : a European journal of chemical biology, 2005Co-Authors: Antonio Trincone, Mose Rossi, Assunta Giordano, Giuseppe Perugino, Marco MoracciAbstract:Transglycosylation reactions (autocondensation of the substrate or transfer of the glycon donor moiety to different acceptors) with the hyperthermophilic glycosynthase from Sulfolobus solfataricus acting in dilute sodium formate buffer at pH 4.0 are reported; the use of 4-nitrophenyl beta-glucopyranoside as both donor and acceptor in the self-transfer reaction and a highly productive reaction with 1.1 M 2-nitrophenyl beta-glucopyranoside were possible. Interesting effects, governed by the anomeric configuration and lipophilicity of heteroacceptors, on the regioselectivity and yield of reactions were found for the first time with this enzyme and are discussed. The results demonstrate the unexplored synthetic potential of this glycosynthase; the tuning of the reaction conditions and the choice of different donors/acceptors can lead to products of applicative interest.
Udo Bläsi - One of the best experts on this subject based on the ideXlab platform.
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Antisense regulation by transposon-derived RNAs in the hyperthermophilic archaeon Sulfolobus solfataricus.
EMBO reports, 2013Co-Authors: Birgit Märtens, David Hasenohrl, Andrea Manica, Salim Manoharadas, Udo BläsiAbstract:We report the first example of antisense RNA regulation in a hyperthermophilic archaeon. In Sulfolobus solfataricus, the transposon-derived paralogous RNAs, RNA-2571–4, show extended complementarity to the 3′ UTR of the 1183 mRNA, encoding a putative phosphate transporter. Phosphate limitation results in decreased RNA-2571 and increased 1183 mRNA levels. Correspondingly, the 1183 mRNA is faster degraded in vitro upon duplex formation with RNA-2571. Insertion of the 1183 3′ UTR downstream of the lacS gene results in strongly reduced lacS mRNA levels in transformed cells, indicating that antisense regulation can function in trans.
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Translation initiation in the crenarchaeon Sulfolobus solfataricus: eukaryotic features but bacterial route
Biochemical Society transactions, 2013Co-Authors: Anna La Teana, Dario Benelli, Paola Londei, Udo BläsiAbstract:The formation of the translation initiation complex represents the rate-limiting step in protein synthesis. Translation initiation in the crenarchaeon Sulfolobus solfataricus depends on several translation IFs (initiation factors), some of which have eukaryal but no bacterial counterparts. In the present paper, we review the current knowledge of the structure, function and evolution of the IFs in S. solfataricus in the context of eukaryotic and bacterial orthologues. Despite similarities between eukaryotic and S. solfataricus IFs, the sequence of events in translation initiation in S. solfataricus follows the bacterial mode.
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Sulfolobus solfataricus translation initiation factor 1 stimulates translation initiation complex formation
RNA, 2006Co-Authors: David Hasenohrl, Dario Benelli, A Barbazza, Paola Londei, Udo BläsiAbstract:The eukaryotic translation initiation factor 1 binds to the ribosome during translation initiation. It is instrumental for initiator-tRNA and mRNA binding, and has a function in selection of the authentic start codon. Here, we show that the archaeal homolog aIF1 has analogous functions. The aIF1 protein of the archaeon Sulfolobus solfataricus is bound to the small ribosomal subunit during translation initiation and accelerates binding of initiator-tRNA and mRNA to the ribosome. Accordingly, aIF1 stimulated translation of an mRNA in a S. solfataricus in vitro translation system. Moreover, this study suggested that the C terminus of the factor is of relevance for its function.
Simonetta Bartolucci - One of the best experts on this subject based on the ideXlab platform.
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Development of a genetic system for hyperthermophilic Archaea: expression of a moderate thermophilic bacterial alcohol dehydrogenase gene in Sulfolobus solfataricus.
FEMS microbiology letters, 2003Co-Authors: Patrizia Contursi, Raffaele Cannio, Santina Prato, Gabriella Fiorentino, Mauro Rossi, Simonetta BartolucciAbstract:The Escherichia coli/Sulfolobus solfataricus shuttle vector pEXSs was used as a cloning vehicle for the gene transfer and expression of two bacterial genes in Sulfolobus solfataricus. The alcohol dehydrogenase (adh) from the moderate thermophilic Bacillus stearothermophilus (strain LLDR) and a mutagenised version encoding a less thermostable ADH enzyme were the selected genes. S. solfataricus adh promoter and aspartate aminotransferase terminator were used to drive the heterologous gene expression and to guarantee the correct termination of the transcripts, respectively. The constructed vectors were found to be able to carry these ‘passenger’ genes without undergoing any rearrangements. The active transcription of bacillar mRNAs was ascertained in vivo by RT-PCR. Transformed S. solfataricus expressed functional exogenous ADHs that showed unaffected kinetic and chemical–physical features.
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An Autonomously Replicating Transforming Vector for Sulfolobus solfataricus
Journal of bacteriology, 1998Co-Authors: Raffaele Cannio, Mose Rossi, Patrizia Contursi, Simonetta BartolucciAbstract:A plasmid able to transform and to be stably maintained both in Sulfolobus solfataricus and in Escherichia coli was constructed by insertion into an E. coli plasmid of the autonomously replicating sequence of the virus particle SSV1 and a suitable mutant of the hph (hygromycin phosphotransferase) gene as the transformation marker. The vector suffered no rearrangement and/or chromosome integration, and its copy number in Sulfolobus was increased by exposure of the cells to mitomycin C.
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a thioredoxin from the extreme thermophilic archaeon Sulfolobus solfataricus
International Journal of Biochemistry, 1994Co-Authors: Annamaria Guagliardi, Valentina Nobile, Simonetta Bartolucci, Mose RossiAbstract:Abstract 1. 1. A purification procedure for a thioredoxin from the extremophilic archaeon Sulfolobus solfataricus is described. 2. 2. The thioredoxin is active in the dithiothreitol-dependent reduction of insulin disulfide bonds. 3. 3. The thioredoxin is a monomer of 24,800 Da; it is an acidic protein with a pi of 4.5. 4. 4. The protein is stable to heating for 3 hr at 90°C. 5. 5. The amino acid composition of S. solfataricus thioredoxin is reported.
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Isolation of a thermostable enzyme catalyzing disulfide bond formation from the archaebacterium Sulfolobus solfataricus
FEBS letters, 1992Co-Authors: Annamaria Guagliardi, Mose Rossi, Mario De Rosa, Laura Cerchia, Simonetta BartolucciAbstract:A disulfide bond-forming enzyme was purified from the cytosol of the archaebacterium Sulfolobus solfataricus, strain MT-4. The enzyme, assayed by its ability to oxidize and reactivate reductively denatured ribonuclease A, had a small molecular size and displayed a high thermostability. The N-terminal amino acid sequence is reported.
Paola Londei - One of the best experts on this subject based on the ideXlab platform.
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Translation initiation in the crenarchaeon Sulfolobus solfataricus: eukaryotic features but bacterial route
Biochemical Society transactions, 2013Co-Authors: Anna La Teana, Dario Benelli, Paola Londei, Udo BläsiAbstract:The formation of the translation initiation complex represents the rate-limiting step in protein synthesis. Translation initiation in the crenarchaeon Sulfolobus solfataricus depends on several translation IFs (initiation factors), some of which have eukaryal but no bacterial counterparts. In the present paper, we review the current knowledge of the structure, function and evolution of the IFs in S. solfataricus in the context of eukaryotic and bacterial orthologues. Despite similarities between eukaryotic and S. solfataricus IFs, the sequence of events in translation initiation in S. solfataricus follows the bacterial mode.
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Sulfolobus solfataricus translation initiation factor 1 stimulates translation initiation complex formation
RNA, 2006Co-Authors: David Hasenohrl, Dario Benelli, A Barbazza, Paola Londei, Udo BläsiAbstract:The eukaryotic translation initiation factor 1 binds to the ribosome during translation initiation. It is instrumental for initiator-tRNA and mRNA binding, and has a function in selection of the authentic start codon. Here, we show that the archaeal homolog aIF1 has analogous functions. The aIF1 protein of the archaeon Sulfolobus solfataricus is bound to the small ribosomal subunit during translation initiation and accelerates binding of initiator-tRNA and mRNA to the ribosome. Accordingly, aIF1 stimulated translation of an mRNA in a S. solfataricus in vitro translation system. Moreover, this study suggested that the C terminus of the factor is of relevance for its function.
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The 23 S Ribosomal RNA of Sulfolobus solfataricus (Strain MT4): Sequence, Structure and Functional Homology with Other 23 S rRNAs of Thermophilic, Sulfur-Dependent Archaea
Systematic and Applied Microbiology, 1993Co-Authors: Aline Martayan, Elisabetta Caprini, Paola LondeiAbstract:Summary The primary and secondary structures of the 23 S ribosomal RNA of the archaeon (archeabacterium) Sulfolobus solfataricus strain MT4, were deduced from the sequence of the cloned gene. The structure of the “processing stem” of the 23 S rRNA was also deduced and the position of some processing cuts was experimentally determined. Sulfolobus solfataricus 23 S rRNA was found to resemble closely in both sequence and structure the 23 S rRNAs of other thermophilic, sulphur-dependent archaea (crenarchaeota), particularly that of Desulfurococcus mobilis. However, ribosome reconstitution experiments demonstrated that the 23 S rRNAs of Sulfolobus and Desulfurococcus were not functionally interchangeable, possibly because of subtle but crucial differences in a region involved in the binding of an assembly-initiating protein.
