5-hydroxy-2-oxo-4-ureido-2,5-dihydro-1H-imidazole-5-carboxylate + H(+) <=> (S)-allantoin + CO2
5-hydroxy-2-oxo-4-ureido-2,5-dihydro-1h-imidazole-5-carboxylate + h(+) <=> (s)-allantoin + co2
5-hydroxy-2-oxo-4-ureido-2,5-dihydro-1H-imidazole-5-carboxylate + H(+) <=> (S)-allantoin + CO2
5-hydroxy-2-oxo-4-ureido-2,5-dihydro-1h-imidazole-5-carboxylate + h(+) <=> (s)-allantoin + co2