Hyperthermophilic Archaea colonizing unnatural habitats of extremes conditions such as volcanoes and deep-sea hydrothermal vents represent an unmeasurable bioresource for enzymes used in various industrial applications. Their enzymes show distinct structural and functional properties and are resistant to extreme conditions of temperature and pressure where their mesophilic homologs fail. In this review, we will outline carbohydrate-active enzymes (CAZymes) from hyperthermophilic Archaea with specific focus on the two largest families, glycoside hydrolases (GHs) and glycosyltransferases (GTs). We will present the latest advances on these enzymes particularly in the light of novel accumulating data from genomics and metagenomics sequencing technologies. We will discuss the contribution of these enzymes from hyperthermophilic Archaea to industrial applications and put the emphasis on newly identifed enzymes. We will highlight their common biochemical and distinct features. Finally, we will overview the areas that remain to be explored to identify novel promising hyperthermozymes.

Helicase proteins are known to use the energy of ATP to unwind nucleic acids and to remodel protein-nucleic acid complexes. They are involved in almost every aspect of DNA and RNA metabolisms and participate in numerous repair mechanisms that maintain cellular integrity. The archaeal Lhr-type proteins are SF2 helicases that are mostly uncharacterized. They have been proposed to be DNA helicases that act in DNA recombination and repair processes in Sulfolobales and Methanothermobacter. In Thermococcales, a protein annotated as an Lhr2 protein was found in the network of proteins involved in RNA metabolism. To investigate this, we performed in-depth phylogenomic analyses to report the classification and taxonomic distribution of Lhr-type proteins in Archaea, and to better understand their relationship with bacterial Lhr. Furthermore, with the goal of envisioning the role(s) of aLhr2 in Thermococcales cells, we deciphered the enzymatic activities of aLhr2 from Thermococcus barophilus (Tbar). We showed that Tbar-aLhr2 is a DNA/RNA helicase with a significant annealing activity that is involved in processes dependent on DNA and RNA transactions.

SF1 and SF2 helicases are important molecular motors that use the energy of ATP to unwind nucleic acids or nucleic-acid protein complexes. They are ubiquitous enzymes and found in almost all organisms sequenced to date. This article provides a comparative analysis for SF1 and SF2 helicase families from three domains of life archaea, human, bacteria. Seven families are conserved in these three representatives and includes Upf1-like, UvrD-like, Rad3-like, DEAD-box, RecQ-like. Snf2 and Ski2-like. The data highlight conservation of the helicase core motifs for each of these families. Phylogenetic analysis presented on certain protein families are essential for further studies tracing the evolutionary history of helicase families. The data supplied in this article support publication “Genome-wide identification of SF1 and SF2 helicases from archaea” (Chamieh et al., 2016) [1].

Free radical-induced damage plays a significant role in the development of type 2 diabetes and its complications. Extracellular superoxide dismutase (EC-SOD) or SOD3 is one of the important scavenger enzymes that protects against oxidative damage and the formation of free radicals. EC-SOD is a copper- and zinc-containing secretory enzyme located in tissues and primarily in the extracellular matrix. EC-SOD has been proposed to protect against pancreatic beta-cell damage, insulin resistance and vascular function in diabetic patients. The association between EC-SOD gene polymorphism and Type 2 diabetes mellitus is not completely understood. The aim of the study is to investigate the EC-SOD gene polymorphism in the exon 3 region and the susceptibility to type 2 diabetes mellitus and its complications among Lebanese patients. For this purpose, a genotype analysis involving 60 Type 2 Diabetes patients and 46 control subjects was carried out using PCR-based direct DNA sequencing. Results showed that the frequency of the Ala40Thr polymorphism of EC-SOD gene was significantly higher in type 2 diabetic patients compared to control group. Evaluation of clinical parameters of diabetic patients with their relative genotypes showed that patients with the Thr allele have higher HbA1c levels and fasting blood glucose compared to their Ala genotypes indicating a poor diabetes control in these patients. When diabetic complications including retinopathy, nephropathy and cardiovascular complications were correlated with Ala40Val polymorphism, a significant association was detected for complications and particularly for cardiovascular diseases in diabetic patients. Key words: Type 2 diabetes mellitus, oxidative stress, extracellular superoxide dismutase, genetic biomarker.