In enzymology, an UMP kinase (EC 188.8.131.52) is an enzyme that catalyzes the chemical reaction
- ATP + UMP ADP + UDP
Thus, the two substrates of this enzyme are ATP and UMP, whereas its two products are ADP and UDP.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with a phosphate group as acceptor. The systematic name of this enzyme class is ATP:UMP phosphotransferase. Other names in common use include uridylate kinase, UMPK, uridine monophosphate kinase, PyrH, UMP-kinase, and SmbA. This enzyme participates in pyrimidine metabolism.
Structural studies 
As of March 2010, 19 structures have been solved for this class of enzymes, and are deposited in the PDB. All have a 3-layer (aba) sandwich) architecture (CATH code 3.40.1160.10). These include accession codes 2J4J, 2J4K, 2J4L, and 2VA1.
Search for all UMP Kinases in the PDB using the enzyme Browser at PDBe. (input the EC number)
- Gilles AM, Barzu O (1995). "Escherichia coli UMP-kinase, a member of the aspartokinase family, is a hexamer regulated by guanine nucleotides and UTP". Biochemistry. 34 (15): 5066–5074. doi:10.1021/bi00015a018. PMID 7711027.
- Marco-Marin C, Gil-Ortiz F, Rubio V (2005). "The crystal structure of Pyrococcus furiosus UMP kinase provides insight into catalysis and regulation in microbial pyrimidine nucleotide biosynthesis". J. Mol. Biol. 352 (2): 438–454. doi:10.1016/j.jmb.2005.07.045. PMID 16095620.