Catalyzes the final step in the metabolic pathway of hydroxyproline. (4S)-4-hydroxy-2-oxoglutarate = glyoxylate + pyruvate (4R)-4-hydroxy-2-oxoglutarate = glyoxylate + pyruvate Inhibited by divalent cations. Homotetramer. Belongs to the DapA family. Extended C-terminus.