Deoxynucleoside kinases

The biosynthesis of deoxynucleoside triphosphates in most living organisms is performed by two pathways, the de novo and the salvage pathway. The principal salvage enzymes are deoxynucleoside kinases, which phosphorylate deoxynucleozides to the corresponding deoxynucleoside monophosphates. A new multifunctional deoxynucleoside kinase, Dm-dNK, was purified from the fruit fly. This enzyme was characterized regarding the kinetics and the corresponding gene was cloned. Several mutants of Dm-dNK were isolated and characterised for substrate specificity and kinetic parameters. In addition, similar enzymes from different organisms, were characterized.