這個基因編碼尿苷5'-單磷酸合酶。編碼的蛋白質是一種雙功能酶，對從頭嘧啶生物合成途徑的最后兩個步驟進行催化。第一個反應是由N-末端的酶-磷酸核糖基轉移酶進行的，該酶將乳清酸轉化為5'-單磷酸鹽。末端反應是由C末端酶OMP脫羧酶進行的，該酶能將5'-單磷酸列替丁轉化為單磷酸尿苷。這個基因的缺陷是遺傳性口腔酸尿的原因。交替剪接導致多個轉錄變體。
This gene encodes a uridine 5'-monophosphate synthase. The encoded protein is a bifunctional enzyme that catalyzes the final two steps of the de novo pyrimidine biosynthetic pathway. The first reaction is carried out by the N-terminal enzyme orotate phosphoribosyltransferase which converts orotic acid to orotidine-5'-monophosphate. The terminal reaction is carried out by the C-terminal enzyme OMP decarboxylase which converts orotidine-5'-monophosphate to uridine monophosphate. Defects in this gene are the cause of hereditary orotic aciduria. Alternate splicing results in multiple transcript variants.