Phosphorylates thymidine, deoxycytidine, and deoxyuridine in the mitochondrial matrix (, ). In non-replicating cells, where cytosolic dNTP synthesis is down-regulated, mtDNA synthesis depends solely on TK2 and DGUOK . Widely used as target of antiviral and chemotherapeutic agents .
Subcellular locations: Mitochondrion
Predominantly expressed in liver, pancreas, muscle, and brain.