The structure of glucose dehydrogenase from the extreme halophile Haloferax mediterranei has been solved at 1.6-Å resolution under crystallization conditions which closely mimic “ in vivo ” intracellular environment. decoration enzyme’s surface with acidic residues is only partially neutralized by bound potassium counterions, also appear to play a role substrate binding. shows expected reduction hydrophobic character, surprisingly not changes associated loss exposed but rather arising...

Despite being the subject of intensive investigations, many aspects mechanism zinc-dependent medium chain alcohol dehydrogenase (MDR) superfamily remain contentious. We have determined high-resolution structures a series binary and ternary complexes glucose dehydrogenase, an MDR enzyme from Haloferax mediterranei. In stark contrast to textbook in which zinc ion is proposed stationary attached common set protein ligands, analysis these reveals that each complex, there are dramatic differences...

Abstract A set of 110 extremely halophilic archaeal strains were isolated from seven distinct saline habitats located in different regions Algeria. The physicochemical characterization the samples showed that these thalassohaline. carotenoid production varied 0.1 to 3.68 µg/ml. Based on their physiological characteristics and pigment production, 43 selected identified by means phenotypic tests 16S ribosomal RNA gene sequencing. Phylogenetic analysis indicated isolates corresponded class...

Haloferax mediterranei, an extreme halophilic archaeon thriving in hypersaline environments, has acquired significant attention biotechnological and biochemical research due to its remarkable ability flourish salinity conditions. Transcription factors, essential regulating diverse cellular processes, have become focal points understanding adaptability. This study delves into the role of Lrp transcription factor, exploring modulation glnA, nasABC, lrp gene promoters vivo through...

The first gene encoding a glucose dehydrogenase (GDH) from halophilic organism has been sequenced. Amino acid sequence alignments of GDH Haloferax mediterranei show high degree homology with the thermoacidophilic GDHs and other enzymes medium chain dehydrogenase/reductase family. Heterologous overexpression using mesophilic Escherichia coli as host performed expression product was obtained inclusion bodies. To obtain enzyme in its native form refolding reactivation saline environment were...

Microorganisms, including Bacteria and Archaea, play a key role in denitrification, which is the major mechanism by fixed nitrogen returns to atmosphere from soil water. While enzymology of denitrification well understood Bacteria, details last two reactions this pathway, catalyse reduction nitric oxide (NO) via nitrous (N2 O) ), are little studied hardly at all haloarchaea. This work describes an extensive interspecies analysis both complete draft haloarchaeal genomes aimed identifying...

The Sm protein superfamily includes Sm, like-Sm (Lsm), and Hfq found in the Eukarya, Archaea, Bacteria domains. Archaeal Lsm proteins have been shown to bind sRNAs are probably involved various cellular processes, suggesting a similar function regulating by bacteria. Moreover, archaeal represent ancestral domain from which eukaryotic evolved. In this work, Haloferax mediterranei was used as model organism because it has widely investigate nitrogen cycle its regulation Haloarchaea. Predicting...

Since the Industrial Revolution, nearly 700 Gt of carbon (GtC) have been emitted into atmosphere as CO2 derived from human activities, which 292 GtC remain uncontrolled. By end this century, atmospheric concentration is predicted to surpass ppm. The effects sudden release on worldwide biogeochemical cycles and balances are not yet fully understood, but global warming climate change undeniable, with gas playing a starring role. Governmental policies international agreements emission reduction...

Abstract Haloarchaea, known for their resilience to environmental fluctuations, require a minimum salt concentration of 10% (w/v) growth and can survive up 35% salinity. In biotechnology, these halophiles have diverse industrial applications. This study investigates the tolerance responses nine haloarchaea: Haloferax mediterranei , volcanii gibbonsii Halorubrum californiense litoreum, Natrinema pellirubrum altunense Haloterrigena thermotolerans Haloarcula sinaiiensis under various stressful...

Generally, halophilic enzymes present a characteristic amino acid composition, showing an increase in the content of acidic residues and decrease basic residues, particularly lysines. The latter appears to be responsible for reduction proportion solvent‐exposed hydrophobic surface. This role was investigated by site‐directed mutagenesis glucose dehydrogenase from Haloferax mediterranei , which surface aspartic were changed lysine residues. From biochemical analysis mutant proteins, it is...

Small RNAs have been studied in detail domains Bacteria and Eukarya but, the case of domain Archaea, knowledge is scarce physiological function these small (sRNAs) still uncertain. To extend sRNAs Archaea their possible role regulation nitrogen assimilation metabolism haloarchaea, Haloferax mediterranei has used as a model microorganism. The bioinformatic approach allowed for prediction 295 putative genes genome H. mediterranei, 88 which verified by means RNA-Sequencing (RNA-Seq). secondary...

Haloarchaea can survive and thrive under exposure to a wide range of extreme environmental factors, which represents potential interest biotechnology. Growth responses different stressful conditions were examined in the haloarchaeon Haloferax mediterranei R4. It has been demonstrated that this halophilic archaeon is able grow between 10 32.5% (w/v) sea water, at 32–52 °C, although it expected temperatures lower than 32 5.75 8.75 pH. Moreover, also high metal concentrations (nickel, lithium,...

The Archaea domain consists of a heterogeneous group microorganisms with unique physiological properties that occupy wide variety niches in nature. Haloferax mediterranei is an extremely halophilic archaeon classified the Phylum Euryarchaeota, which requires high concentration inorganic salts for optimal growth. In haloarchaea, transcription factors play fundamental role adequate adaptation to environmental and nutritional changes, preserving survival integrity organism. To deepen knowledge...

The glutamine synthetase (EC 6.3.1.2) from the haloarchaeon Haloferax mediterranei has been purified and characterized in order to understand ammonium assimilation haloarchaea. Based on sodium dodecyl sulfate polyacrylamide gel electrophoresis gel-filtration chromatography, enzyme consists of eight subunits 51.7 kDa, suggesting that this belongs type II. with respect its optimum temperature (45 degrees C) pH value (8.0). optimal NaCl or KCl concentrations for reaction were 0.5 0.25 M,...