A Phosphofructokinase Homolog from Pyrobaculum calidifontis Displays Kinase Activity towards Pyrimidine Nucleosides and Ribose 1-Phosphate

Abstract

The discovery of the pentose bisphosphate pathway in Thermococcus kodakarensis has clarified how this archaeon can degrade nucleosides. Homologs of the enzymes of this pathway are present in many members of the Thermococcales, suggesting that this metabolism occurs in these organisms. However, this is not the case in other archaea, and degradation mechanisms for nucleosides or ribose 1-phosphate are still unknown. This study reveals an important first step in understanding nucleoside metabolism in Crenarchaeota and identifies an ATP-dependent ribose 1-phosphate kinase in Pyrobaculum calidifontis . The enzyme is structurally distinct from previously characterized archaeal members of the ribokinase family and represents a group of proteins found in many crenarchaea.