ExplorEnz: EC 5.1.99.5

Your query returned 1 entry. Printable version

5.1.99.5

Accepted name:

hydantoin racemase

Reaction:

D-5-monosubstituted hydantoin = L-5-monosubstituted hydantoin

Glossary:

hydantoin = imidazolidine-2,4-dione

Other name(s):

5′-monosubstituted-hydantoin racemase; HyuA; HyuE

Systematic name:

D-5-monosubstituted-hydantoin racemase

Comments:

This enzyme, along with N-carbamoylase (EC 3.5.1.77 and EC 3.5.1.87) and hydantoinase, forms part of the reaction cascade known as the "hydantoinase process", which allows the total conversion of D,L-5-monosubstituted hydantoins into optically pure D- or L-amino acids [7]. The enzyme from Pseudomonas sp. (HyuE) has a preference for hydantoins with aliphatic substituents, e.g. D- and L-5-[2-(methylsulfanyl)ethyl]hydantoin, whereas that from Arthrobacter aurescens shows highest activity with arylalkyl substituents, especially 5-benzylhydantoin, at the 5-position [2]. In the enzyme from Sinorhizobium meliloti, Cys⁷⁶ is responsible for recognition and proton retrieval of D-isomers, while Cys¹⁸¹ is responsible for L-isomer recognition and racemization [6].

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Watabe, K., Ishikawa, T., Mukohara, Y. and Nakamura, H. Purification and characterization of the hydantoin racemase of Pseudomonas sp. strain NS671 expressed in Escherichia coli. J. Bacteriol. 174 (1992) 7989–7995. [DOI] [PMID: 1459947]
2.	Wiese, A., Pietzsch, M., Syldatk, C., Mattes, R. and Altenbuchner, J. Hydantoin racemase from Arthrobacter aurescens DSM 3747: heterologous expression, purification and characterization. J. Biotechnol. 80 (2000) 217–230. [DOI] [PMID: 10949312]
3.	Martínez-Rodríguez, S., Las Heras-Vázquez, F.J., Mingorance-Cazorla, L., Clemente-Jiménez, J.M. and Rodríguez-Vico, F. Molecular cloning, purification, and biochemical characterization of hydantoin racemase from the legume symbiont Sinorhizobium meliloti CECT 4114. Appl. Environ. Microbiol. 70 (2004) 625–630. [DOI] [PMID: 14711700]
4.	Martínez-Rodríguez, S., Las Heras-Vázquez, F.J., Clemente-Jiménez, J.M. and Rodríguez-Vico, F. Biochemical characterization of a novel hydantoin racemase from Agrobacterium tumefaciens C58. Biochimie 86 (2004) 77–81. [DOI] [PMID: 15016445]
5.	Suzuki, S., Onishi, N. and Yokozeki, K. Purification and characterization of hydantoin racemase from Microbacterium liquefaciens AJ 3912. Biosci. Biotechnol. Biochem. 69 (2005) 530–536. [DOI] [PMID: 15784981]
6.	Martínez-Rodríguez, S., Andújar-Sánchez, M., Neira, J.L., Clemente-Jiménez, J.M., Jara-Pérez, V., Rodríguez-Vico, F. and Las Heras-Vázquez, F.J. Site-directed mutagenesis indicates an important role of cysteines 76 and 181 in the catalysis of hydantoin racemase from Sinorhizobium meliloti. Protein Sci. 15 (2006) 2729–2738. [DOI] [PMID: 17132860]
7.	Altenbuchner, J., Siemann-Herzberg, M. and Syldatk, C. Hydantoinases and related enzymes as biocatalysts for the synthesis of unnatural chiral amino acids. Curr. Opin. Biotechnol. 12 (2001) 559–563. [DOI] [PMID: 11849938]

[EC 5.1.99.5 created 2008]