Screening process for hydantoin racemases
The present invention relates to a screening process for hydantoin racemases and to novel hydantoin racemases, to the nucleic acid sequences coding therefor and to a proces for mutagenesis. Hydantoin racemases are of interest in connection with the production of enantiomerically enriched amino acids from racemic hydantoins.
1. An isolated, mutated hydantoin racemase, comprising the amino acid sequence of SEQ ID NO:2 but wherein the the amino acids at positions 78-83 in SEQ ID NO:2 are: FX 1 DX 2 GL (SEQ ID NO:1), wherein X 2 represents P or T and X 1 is at position 79 and is an amino acid selected from the group consisting of: A, R, N, D, C, Q, E, H, I, L, K, M, F, P, S, T, Y and V.
2. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is A.
3. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is R.
4. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is N.
5. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is D.
6. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is C.
7. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is Q.
8. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is E.
9. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is H.
10. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is I.
11. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is K.
12. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is L.
13. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is M.
14. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is F.
15. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is P.
16. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is S.
17. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is T.
18. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is Y.
19. The mutated hydantoin racemase of claim 1 , wherein the amino acid at position 79 is V.
20. A method of making enantiomerically enriched N-carbamoyl-amino acids or amino acids comprising reacting hydantoin molecules with a hydantoinase and with the mutated hydantoin racemase of claim 1 .