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| Zappa, Sebastien; Rolland, Jean-luc; Flament, Didier; Gueguen, Yannick; Boudrant, Joseph; Dietrich, Jacques. |
| This work reports the first isolation and characterization of an alkaline phosphatase (AP) from a hyperthermophilic archaeon. An AP gene from Pyrococcus abyssi, a euryarchaeon isolated from a deep-sea hydrothermal vent, was cloned and the enzyme expressed in Escherichia coli. Analysis of the sequence showed conservation of the active site and structural elements of the E. coli AP. The recombinant AP was purified and characterized. Monomeric and homodimeric active forms were detected, with a monomer molecular mass of 54 kDa. Apparent optimum pH and temperature were estimated at 11.0 and 70 degreesC, respectively. Thus far, P. abyssi AP has been demonstrated to be the most thermostable AP, with half-lives at 100 and 105 degreesC of 18 and 5 h, respectively.... |
| Tipo: Text |
Palavras-chave: Escherichia coli; Characterization; Isolation; Gene; Alkaline phosphatase; Pyrococcus abyssi; Archaeon. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1268.pdf |
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| Godfroy, Anne; Raven, N; Sharp, R. |
| The deep-sea vent archaeon Pyrococcus abyssi strain ST549 was grown in batch cultures in closed bottles and by continuous culture in a gas-lift bioreactor, both in the presence and in the absence of elemental sulfur. Growth on carbohydrates, proteinaceous substrates and amino acids was investigated. The disaccharides maltose and cellobiose were shown not to be able to enhance growth suggesting that P. abyssi ST549 is unable to use them as carbon sources. By contrast, proteinaceous substrates such as peptone and brain heart infusion were shown to be very good substrates for the growth of P. abyssi ST549 and allowed growth at high steady-state cell densities in continuous culture. Growth on brain heart infusion was shown to require additional nutrients when... |
| Tipo: Text |
Palavras-chave: Sulfur requirement; Continuous culture; Nutrition; Hyperthermophile; Pyrococcus abyssi. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-1087.pdf |
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| Henneke, Ghislaine; Gueguen, Yannick; Flament, Didier; Azam, Philippe; Querellou, Joel; Dietrich, Jacques; Hubscher, Ulrich; Raffin, Jean-paul. |
| The molecular organization of the replication complex in archaea is similar to that in eukaryotes. Only two proteins homologous to subunits of eukaryotic replication factor C (RFC) have been detected in Pyrococcus abyssi (Pab). The genes encoding these two proteins are arranged in tandem. We cloned these two genes and co-expressed the corresponding recombinant proteins in Escherichia coli. Two inteins present in the gene encoding the small subunit (Pab RFC-small) were removed during cloning. The recombinant protein complex was purified by anion-exchange and hydroxyapatite chromatography. Also, the Pab RFC-small subunit could be purified, while the large subunit (Pab RFC-large) alone was completely insoluble. The highly purified Pab RFC complex possessed an... |
| Tipo: Text |
Palavras-chave: PCNA binding domain; Pyrococcus abyssi; Hyperthermophile; Archaea; Replication factor C. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/2002/publication-675.pdf |
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| Malfatti, Matilde Clarissa; Henneke, Ghislaine; Balachander, Sathya; Koh, Kyung Duk; Newnam, Gary; Uehara, Ryo; Crouch, Robert J.; Storici, Francesca; Tell, Gianluca. |
| The presence of ribonucleoside monophosphates (rNMPs) in nuclear DNA decreases genome stability. To ensure survival despite rNMP insertions, cells have evolved a complex network of DNA repair mechanisms, in which the ribonucleotide excision repair pathway, initiated by type 2 ribonuclease H (RNase HII/2), plays a major role. We recently demonstrated that eukaryotic RNase H2 cannot repair damaged, that is, ribose monophosphate abasic (both apurinic or apyrimidinic) site (rAP) or oxidized rNMP embedded in DNA. Currently, it remains unclear why RNase H2 is unable to repair these modified nucleic acids having either only a sugar moiety or an oxidized base. Here, we compared the endoribonuclease specificity of the RNase HII enzymes from the archaeon Pyrococcus... |
| Tipo: Text |
Palavras-chave: Ribonuclease; Bacteria; Escherichia coli (E coli); Archaea; Oxidative stress; Abasic-ribose; Oxidized-ribonucleotides; Pyrococcus abyssi; Type 2 RNase H. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00506/61796/65801.pdf |
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