Enables ribose-5-phosphate isomerase activity. Predicted to be involved in D-ribose metabolic process; pentose-phosphate shunt, non-oxidative branch; and ribose phosphate metabolic process. Predicted to be active in intracellular membrane-bounded organelle. Is expressed in alimentary system; liver; lung; and respiratory system. Orthologous to human RPIA (ribose 5-phosphate isomerase A). [provided by Alliance of Genome Resources, Apr 2022]