Enables prostaglandin-D synthase activity and prostaglandin-E synthase activity. Involved in several processes, including prostaglandin biosynthetic process; response to lipopolysaccharide; and response to retinoic acid. Located in intracellular membrane-bounded organelle and perinuclear region of cytoplasm. Biomarker of Barrett's esophagus; ischemia; papilloma; peptic esophagitis; and transitional cell carcinoma. Orthologous to human PTGES (prostaglandin E synthase). [provided by Alliance of Genome Resources, Apr 2022]