KEGG Orthology (KO) [BR:std00001] 09100 Metabolism 09104 Nucleotide metabolism 00240 Pyrimidine metabolism [PATH:std00240] SPPN_05105 thymidine kinase K00857 tdk; thymidine kinase [EC:2.7.1.21] Enzymes [BR:std01000] 2. Transferases 2.7 Transferring phosphorus-containing groups 2.7.1 Phosphotransferases with an alcohol group as acceptor 2.7.1.21 thymidine kinase SPPN_05105 thymidine kinase K00857 tdk; thymidine kinase [EC:2.7.1.21]