Biochemical and Structural Characterisation of a Novel D-Lyxose Isomerase From the Hyperthermophilic Archaeon sp.

A novel D-lyxose isomerase has been identified within the genome of a hyperthermophilic archaeon belonging to the species. The enzyme has been cloned and over-expressed in and biochemically characterised. This enzyme differs from other enzymes of this class in that it is highly specific for the substrate D-lyxose, showing less than 2% activity towards mannose and other substrates reported for lyxose isomerases.

Glucose Metabolism and Acetate Switch in Archaea: the Enzymes in Haloferax volcanii.

The halophilic archaeon has been proposed to degrade glucose via the semiphosphorylative Entner-Doudoroff (spED) pathway. Following our previous studies on key enzymes of this pathway, we now focus on the characterization of enzymes involved in 3-phosphoglycerate conversion to pyruvate, in anaplerosis, and in acetyl coenzyme A (acetyl-CoA) formation from pyruvate. These enzymes include phosphoglycerate mutase, enolase, pyruvate kinase, phosphoenolpyruvate carboxylase, and pyruvate-ferredoxin oxidoreductase.

Acetate Metabolism in Archaea: Characterization of an Acetate Transporter and of Enzymes Involved in Acetate Activation and Gluconeogenesis in .

The haloarchaeon grows on acetate as sole carbon and energy source. The genes and proteins involved in uptake and activation of acetate and in gluconeogenesis were identified and analyzed by characterization of enzymes and by growth experiments with the respective deletion mutants. (i) An acetate transporter of the sodium: solute-symporter family (SSF) was characterized by kinetic analyses of acetate uptake into cells.