Enables orotate phosphoribosyltransferase activity and orotidine-5'-phosphate decarboxylase activity. Involved in several processes, including UMP biosynthetic process; female pregnancy; and lactation. Predicted to be located in cytoplasm and nucleus. Human ortholog(s) of this gene implicated in orotic aciduria and purine-pyrimidine metabolic disorder. Orthologous to human UMPS (uridine monophosphate synthetase). [provided by Alliance of Genome Resources, Apr 2022]