Ruta (commonly known as rue) is a genus of strongly scented evergreen subshrubs, 20–60 cm tall, in the family Rutaceae, native to the Mediterranean region, Macaronesia and southwest Asia. There are perhaps 8 to 40 species in the genus. The most well-known species is Ruta graveolens (rue or common rue).

Pyrimidine oxygenase (, RutA) is an enzyme with system name uracil,FMNH₂:oxygen oxidoreductase (uracil hydroxylating, ring-opening) . This enzyme catalyses the following chemical reaction