Phosphorylates deoxyguanosine and deoxyadenosine in the mitochondrial matrix, with the highest efficiency for deoxyguanosine (PubMed:8692979, PubMed:8706825, PubMed:11687801, PubMed:17073823, PubMed:23043144). In non-replicating cells, where cytosolic dNTP synthesis is down-regulated, mtDNA synthesis depends solely on DGUOK and TK2. Phosphorylates certain nucleoside analogs (By similarity). Widely used as target of antiviral and chemotherapeutic agents. 2'-deoxyguanosine + ATP = ADP + dGMP + H(+) 2'-deoxyadenosine + ATP = ADP + dAMP + H(+) Homodimer. Ubiquitous. Highest expression in muscle, brain, liver and lymphoid tissues. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the DCK/DGK family.