The role of thymidine kinases in the activation of pyrimidine nucleoside analogues.

Deoxynucleoside analogues need activation by deoxynucleoside kinases to serve as antiviral or anticancer agents. Here we review the properties of cellular cytoplasmic thymidine kinase 1, mitochondrial thymidine kinase 2, the multisubstrate deoxynucleoside kinase from Drosophila melanogaster and Herpes virus 1 thymidine kinase. Important substrate activity relationships will be discussed.