Function
Uridylate kinase (UK) catalyzes the reversible transfer of phosphate from UMP to UDP using ATP as a phosphate source. UDP is the starting point of synthesis of all other pyrimidine nucleotides. The eukaryotic UK has specificity to both UMP and CMP while the bacterial one is specific for UMP. The bacterial UK is Mg+2 dependent and is activated by GTP and repressed by UTP. The bacterial UK is composed of a C terminal ATP-binding domain and an N terminal UMP-binding domain[1].
Structural highlights
The biological assembly of Uridylate kinase from Sulfolobus solfataricus (2j4k) is . The and excludes purine nucleotides[2]. Water molecule is shown as red sphere.