Enables prostaglandin-D synthase activity. Involved in prostaglandin biosynthetic process; regulation of fever generation; and sensory perception of pain. Acts upstream of or within negative regulation of cell population proliferation; positive regulation of prostaglandin secretion; and prostaglandin metabolic process. Located in cytoplasm and nuclear envelope lumen. Is expressed in several structures, including alimentary system; brain; genitourinary system; integumental system; and sensory organ. Orthologous to human PTGES (prostaglandin E synthase). [provided by Alliance of Genome Resources, Apr 2022]