Involved in the asymmetric conversion of racemic 5-substituted hydantoins to the corresponding L-amino acids. Prefers L-carbamoyl-L-tryptophan and N-carbamoyl-L-tyrosine. Has weaker activity with N-carbamoyl-D,L-phenylalanine and N-carbamoyl-L-thienyalanine. Carbamoyl derivatives of beta-alanine and charged aliphatic amino acids are not accepted as substrates. an N-carbamoyl-L-alpha-amino acid + 2 H(+) + H2O = an L-alpha-amino acid + CO2 + NH4(+) Binds 2 divalent metal cations per subunit. kcat is 5.1 sec(-1) with L-carbamoyl-L-tryptophan as substrate. kcat is 6.5 sec(-1) with N-carbamoyl-L-tyrosine as substrate. kcat is 5.0 sec(-1) with N-carbamoyl-D,L-phenylalanine as substrate. kcat is 16.1 sec(-1) with N-carbamoyl-L-thienyalanine as substrate. Optimum pH is 8.5. Optimum temperature is 50 degrees Celsius. Homodimer. Can be used for the industrial production of optically pure L-amino acids. Belongs to the peptidase M20 family.