Background：Pyrimidine nucleoside monophosphate kinase [UMP/CMP kinase(UMP/CMPK)](CMPK1) is also named as CMK, CMPK, UCK, UMK, UMPK and belongs to the adenylate kinase family. It plays a crucial role in the formation of UDP, CDP, and dCDP, which are required for cellular nucleic acid synthesis(PMID:11912132). CMPK1 can use a broad spectrum of phosphate donors but the best phosphate donors are ATP and dATP. The longest deduced protein contains 228 amino acids and has a calculated molecular mass of 26 kD. However, translation likely begins at the second initiation methionine, resulting in a protein of 196 amino acids(PMID:10462544). The shorter form is the endogenously translated protein(PMID:11912132).
