| deoxynucleoside kinase | |
| Ec Number: | 2.7.1.145 |
| Cas Number: | 52227-81-3 |
| Go Code: | 0019136 |
Deoxynucleoside kinases are generally grouped into two families based on structural homology:
TK1 family. This family has got its name from the human enzyme thymidine kinase 1. The substrate specificity is restricted to thymidine (and to lesser extent deoxyuridine) among the natural substrates. TK1 family members are widespread and found in eukaryotes as well as prokaryotes.
Non-TK1-like family. This family includes deoxycytidine kinase (cytosolic) as well as the two mitochondrial enzymes deoxyguanosine kinase and thymidine kinase 2 in humans. The base specificity is generally broader than for the TK-1 family. Non-TK1 family members are widespread and found in eukaryotes as well as prokaryotes. Also the herpesvirus thymidine kinase belongs to this family although it is not obvious from the sequence homology (it is still structurally related).
In enzymology, a deoxynucleoside kinase is an enzyme that catalyzes the chemical reaction
ATP + 2'-deoxynucleoside
\rightleftharpoons
Thus, the two substrates of this enzyme are ATP and 2'-deoxynucleoside, whereas its two products are ADP and 2'-deoxynucleoside 5'-phosphate.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:deoxynucleoside 5'-phosphotransferase. Other names in common use include multispecific deoxynucleoside kinase, ms-dNK, multisubstrate deoxyribonucleoside kinase, multifunctional deoxynucleoside kinase, D. melanogaster deoxynucleoside kinase, and Dm-dNK.
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes,,,, and .