A5084243464- Bacterial Genetics and Biotechnology
- DNA Repair Mechanisms
- Bacteriophages and microbial interactions
- RNA and protein synthesis mechanisms
- Enzyme Structure and Function
- Enzyme Production and Characterization
- Genomics and Phylogenetic Studies
- Microbial Metabolites in Food Biotechnology
- Protist diversity and phylogeny
- Seaweed-derived Bioactive Compounds
- DNA and Nucleic Acid Chemistry
- Methane Hydrates and Related Phenomena
- CRISPR and Genetic Engineering
- Microbial Community Ecology and Physiology
- RNA modifications and cancer
- Cancer Research and Treatments
- Glycosylation and Glycoproteins Research
- Protease and Inhibitor Mechanisms
- S100 Proteins and Annexins
- Invertebrate Immune Response Mechanisms
- Bone and Dental Protein Studies
- Photosynthetic Processes and Mechanisms
- RNA Research and Splicing
- Bacterial biofilms and quorum sensing
- Enterobacteriaceae and Cronobacter Research
Centre National de la Recherche Scientifique
2012-2024
Ifremer
2013-2024
Université de Bretagne Occidentale
2013-2024
Lebanese University
2021
Institut Universitaire Européen de la Mer
2006-2018
Centre National pour la Recherche Scientifique et Technique (CNRST)
2011
Biology of Extremophiles Laboratory
2007
Station Biologique de Roscoff
1999-2007
Sorbonne Université
2007
The hyperthermophilic euryarchaeon Pyrococcus abyssi and the related species furiosus horikoshii, whose genomes have been completely sequenced, are presently used as model organisms in different laboratories to study archaeal DNA replication gene expression develop genetic tools for hyperthermophiles. We performed an extensive re-annotation of genome P. obtain integrated view its phylogeny, molecular biology physiology. Many new functions predicted both informational operational proteins....
Two β-agarase genes, agaA and agaB, were functionally cloned from the marine bacterium Zobellia galactanivorans. The agaB genes encode proteins of 539 353 amino acids respectively, with theoretical masses 60 40 kDa. These two β-agarases feature homologous catalytic domains belonging to family GH-16. However, AgaA displays a modular architecture, consisting domain (AgaAc) C-terminal unknown function which are processed during secretion enzyme. In contrast, AgaB is composed module signal...
Abstract Replication Protein A (RPA) is a heterotrimeric single stranded DNA-binding protein with essential roles in DNA replication, recombination and repair. Little known about the structure of RPA Archaea, third domain life. By using an integrative structural, biochemical biophysical approach, we extensively characterize from Pyrococcus abyssi presence absence DNA. The obtained X-ray cryo-EM structures reveal that trimerization core interactions promoting clustering on ssDNA are shared...
M42 peptidases are half-megadalton aminopeptidases characterized by a tetrahedral architecture (TET) ubiquitous across all domains of life. Despite their widespread occurrence, evolutionary history and functional diversity remain largely unexplored. Here we show an unsuspected untapped wealth archaeal TET peptidases, exhibiting remarkable heterogeneity, as illustrated the characterization six novel enzymes. Using structural biology, phylogeny, enzymatic studies, establish robust criteria for...
ABSTRACT This work reports the first isolation and characterization of an alkaline phosphatase (AP) from a hyperthermophilic archaeon. An AP gene Pyrococcus abyssi , euryarchaeon isolated deep-sea hydrothermal vent, was cloned enzyme expressed in Escherichia coli . Analysis sequence showed conservation active site structural elements E. AP. The recombinant purified characterized. Monomeric homodimeric forms were detected, with monomer molecular mass 54 kDa. Apparent optimum pH temperature...
Only one virus-like particle (VLP) has been reported from hyperthermophilic Euryarchaeotes. This VLP, named PAV1, is shaped like a lemon and was isolated strain of "Pyrococcus abyssi," deep-sea isolate. Its genome consists double-stranded circular DNA 18 kb which also present at high copy number (60 per chromosome) free within the host cytoplasm but not integrated into chromosome. Here, we report results complete analysis PAV1 genome. All 25 predicted genes, except 3, are located on strand....
The gene encoding the alpha-agarase from "Alteromonas agarilytica" (proposed name) has been cloned and sequenced. product (154 kDa) is unrelated to beta-agarases instead belongs a new family of glycoside hydrolases (GH96). also displays complex modularity, with presence five thrombospondin type 3 repeats three carbohydrate-binding modules.
Abstract Background The production of stable and soluble proteins is one the most important steps prior to structural functional studies biological importance. We investigated parallel in a medium throughput strategy genes coding for from various marine organisms, using protocols that involved recombinatorial cloning, protein expression screening batch purification. This was applied order respond need post-genomic validation recent success large number genomic projects. Indeed, upcoming...
The complete genome sequence of the hyperthermophilic archaeon Pyrococcus abyssi revealed presence a family B DNA polymerase (Pol I) and D II). To extend our knowledge about euryarchaeal polymerases, we cloned genes encoding these two enzymes expressed them in Escherichia coli. polymerases I Pol II) were purified to homogeneity characterized. had molecular mass approximately 90 kDa, as estimated by SDS/PAGE. optimum pH Mg(2+) concentration 8.5-9.0 3 mm, respectively. II is composed subunits...
In this study, we developed a gene disruption system for Thermococcus barophilus using simvastatin positive selection and 5-fluoroorotic acid (5-FOA) negative or counterselection to obtain markerless deletion mutants single- double-crossover events. Disruption plasmids carrying flanking regions of each targeted were constructed introduced by transformation into wild-type T. MP cells. Initially, pyrF mutant was obtained as starting point the construction further mutants. A hisB also in...
In Archaea, the proteins involved in genetic information processing pathways, including DNA replication, transcription, and translation, share strong similarities with those of eukaryotes. Characterizations components eukaryotic-type replication machinery complex provided many interesting insights into both domains. contrast, repair processes hyperthermophilic archaea are less well understood very little is known about intertwining between synthesis, recombination pathways. The development...
A gene disruption system for Thermococcus barophilus was developed using simvastatin (HMG-CoA reductase encoding gene) positive selection and 5-Fluoroorotic acid (5-FOA), a pyrF negative selection. Multiple mutants were constructed with this system, which offers the possibility of complementation in trans, but produces many false positives (<80%). To significantly reduce rate positives, we used another counterselective marker, 6-methylpurine (6-MP), toxic analog adenine kodakarensis,...
The mechanisms underpinning the replication of genomic DNA have recently been challenged in
Abstract A network of RNA helicases, endoribonucleases and exoribonucleases regulates the quantity quality cellular RNAs. To date, mechanistic studies focussed on bacterial eukaryal systems due to challenge identifying main drivers decay processing in Archaea. Here, our data support that aRNase J, a 5′-3′ exoribonuclease β-CASP family conserved Euryarchaeota, engages specifically with Ski2-like helicase exosome potentially exert control over surveillance, at vicinity ribosome. Proteomic...